NYSGA 2012
Field Trip Guidebook
for the
84th Annual Meeting of the
New York State Geological Association
Edited by: Todd W. Rayne
Hosted by:
Hamilton College
Clinton, NY
September 28th-30th, 2012
This guidebook was published by the New York State Geological Association.
Additional copies may be obtained from the Executive Secretary of the NYSGA.
Dr. Alan Benimoff
Executive Secretary, NYSGA
Dept of Engineering, Physics, and Science
College of Staten Island
Staten Island, NY 10314

A1: GEOLOGY OF THE BLACK RIVER VALLEY AND THE WESTERN ADIRONDACK HIGHLANDS.
Robert S. Darling
Geology Department
SUNY College at Cortland
Cortland, NY 13045
robert.darling@cortland.edu
INTRODUCTION
The Black River, in northern New York State, flows along a course that mostly follows the unconformity between Ordovician sedimentary rocks (to the west) and Proterozoic gneisses of the Adirondack Highlands (to the east; Figure 1). Consequently, the region has attracted sedimentologists, stratigraphers, paleontologists, mineralogists, and metamorphic & igneous petrologists. Our trip, however, will focus almost entirely on the Proterozoic metaigneous and meta-sedimentary rocks.
The Adirondack region of northern New York State is a roughly circular dome of highgrade metamorphic and igneous rocks that form a southeast extension of the Grenville Province in Canada (inset of Figure 2). The Adirondack Highlands comprise mostly metaigneous rocks (anorthosites, charnockites, mangerites, gabbros, and granites) whereas the Adirondack Lowlands comprise mostly meta-sedimentary rocks (calc-silicates, marbles, metapelites). The Lowlands are separated from the Highlands by the Carthage-Colton mylonite zone (CCMZ), which shows extensive down-to-the-northwest relative motion from the collapse of the Ottawan phase of the Grenville Orogenic cycle (Rivers, 2008). The CCMZ is a metamorphic facies boundary as well, with upper amphibolite facies metamorphic rocks in the Lowlands and granulite facies metamorphic rocks in the Highlands.
As shown in Figure 2, Proterozoic rocks in the western Adirondacks are characterized by mostly charnockites and granites, with lesser amounts of amphibolite and metasedimentary rocks (metapelites and calcsilicates). Radiometric dating in the area has largely concentrated on the Lyon Mtn granite (McLelland et al., 2001, 2002b) and surrounding metapelites (Florence et al., 1995). The radiometric dates of zircon fall into two general categories, those associated with the Ottawan phase of the Grenville Orogeny (ca. 1050-1090 Ma) and those associated with earlier anorthosite-mangerite-charnockite-granite (AMCG) magmatism (1145-1160 Ma).
The metapelitic rocks have been the focus of two metamorphic studies (Florence et al., 1995; Darling et al., 2004) and pressure-temperature (PT) conditions of 700-770°C, 4.0-6.4 kb near Port Leyden, NY, and 830°C and 6.0-7.2 kb near Moose River, NY, have been determined, respectively. These PT conditions are well into the granulite-facies, but the lower than average pressures reported by Florence et al. (1995) suggest mid-crustal burial depths with an elevated geotherm. The metamorphic temperatures determined in the aforementioned studies are considerably higher than those projected by Bohlen et al. (1985) for the western Adirondacks.
On this trip, we will visit a number of unusual meta-igneous and meta-sedimentary rock types. The basic itinerary is as follows:
Stop 1.— Calc-silicate and sillimanite bearing gneisses on Rt. 12.
Stop 2.— Port Leyden nelsonite.
Stop 3.— Ordovician-age spheroidal weathering at the Knox unconformity.
Stop 4.— Two-pyroxene amphibolite at Lyons Falls, NY
Stop 5.— Hydrothermal quartz + sillimanite veins and pegmatite at Lyonsdale, NY
Stop 6.— Prismatine locality at Moose River, NY
More detailed rock descriptions and interpretations are included under each of the six stops.

A1: GEOLOGY OF THE BLACK RIVER VALLEY AND THE WESTERN ADIRONDACK HIGHLANDS.

STOP 1. Calc-silicate- and sillimanite-bearing gneisses.
The large roadcut here comprises strongly foliated, northwest dipping, augite + K-feldspar + quartz + biotite gneiss. This rock occurs in a narrow but traceable band extending to the northeast under the Pleistocene deltaic sands and reappearing along the Moose River (Florence et al., 1995). The unconformity with Middle Ordovician sedimentary rocks is directly across the highway from this exposure, although it is not well exposed.
Other minerals occurring here include grandite garnet, titanite, wollastonite, calcite and scapolite. Florence and Darling (1997) report that the garnet is mostly grossular and the scapolite is mostly meionitic. The wollastonite contains thin rims of retrograde garnet similar to that described by Valley et al. (1983) from drill cores just 3 km northeast of this location. Interestingly, the garnet described by Valley et al. (1983) contains up to 0.76 wt. % stoichiometric fluorine. Wollastonite is also in contact with calcite and quartz.
As noted in some other Adirondack marbles, the presence of regional metamorphic wollastonite suggests a locally H2O-rich fluid composition (Valley and Essene, 1977; 1980). At PT conditions in this region (700-750°C, 4-6 kbar; Florence et al., 1995) a fluid composition of XH2O = 0.8 to 0.9 is necessary to stabilize wollastonite, quartz and calcite (Jacobs and Kerrick, 1981). The margins of some quartz + pink K-feldspar veins are characterized by epidote + specular hematite suggesting a higher fluid O2 fugacity than in the country rock interior. Very small and uncommon grains of amethyst have been observed in veins here, consistent with high O2 fugacities.
A few meters to the north is a small exposure of leucocratic feldspar + quartz + sillimanite gneiss. Small amounts of biotite, magnetite and almandine garnet occur as well. The sillimanite does not occur in quartz veins like at Stop 5, but instead as small, sometimes radiating clusters. The rock’s proximity to the calc-silicates suggests a metasedimentary origin. Also, note the convoluted reddish-pink color patterns in the gneiss. Note that the reddish-pink color is absent from rocks close to small fractures in the gneiss. This suggests that reducing fluids at one time penetrated these reddish-pink rocks, and either dissolved or replaced the earthy hematite inclusions that occupied fractures and cleavages in the K-feldspar. It is conceivable that the reddish-pink color of felsic gneiss here and elsewhere in proximity to the Knox unconformity throughout the Black River Valley is the result of Ordovician-age chemical weathering, an argument supported by spheroidal weathering at Stop 3.

STOP 2. Port Leyden nelsonite
This is one of two occurrences of nelsonite in New York State (Darling and Florence, 1995). The other occurs near Cheney Pond, 110 km to the northeast, in the High Peaks region of the Adirondacks (Kolker, 1980; 1982). At Port Leyden, the nelsonite occurs as a dike about 3 to 4 meters wide and is traceable for about 30 meters to the north. The host rock is metapelitic gneiss comprising K-feldspar, quartz, garnet, biotite, sillimanite and spinel.
Nelsonites are igneous rocks comprising apatite and Fe-Ti oxides such as ilmenite, or magnetite and rutile. The Port Leyden nelsonite has 32-50% magnetite, 8-15% ilmenite, 30-45% apatite, and 5-11% pyrite (Darling and Florence, 1995). Chlorite and garnet occur as well, and zircon and monazite are observed in thin section. A characteristic feature is its overall fine-grain texture, a common attribute of nelsonites (A. Philpotts, personal communication). See Figure 3.
Nelsonites are normally associated with anorthosite-suite rocks (like at Cheney Pond) and there are two competing theories on their origin. They are believed to form by either magmatic immiscibility (Philpotts, 1967; 1981) or by cumulate processes (Dymek and Owens, 2001), but in both cases the source rocks are either anorthosites or oxide-apatite gabbro norites. Neither of these two rocks occurs within the vicinity of Port Leyden and so the parent rock of the Port Leyden nelsonite is unknown. It is possible that the parent rocks once existed in the Port Leyden area and were eroded away. This is plausible because Philpotts (1981) suggests that nelsonites actually intrude downward in the crust due to their high liquid density (∼4.0 gm/cm3). It is also possible that anorthosite-suite rocks currently located near Carthage, NY (∼50 km to the north-northwest) could be a potential source rock as the Adirondack Lowlands once existed structurally on top of the Adirondack Highlands and slid in a NW direction along the CCMZ late in the history of the Grenville Orogeny (Rivers, 2008). This would require greater that 50 km of horizontal displacement along the CCMZ, however.
Radiometric dates have not been published for the Port Leyden nelsonite but it is believed to coincide with intrusion of the AMCG suite, which McLelland et al. (2004) state occurred ca. 1155 Ma. This is interesting because the nelsonite dike cross-cuts the foliation in the metapelite, which would suggest that deformation and metamorphism of the host rocks predates the AMCG igneous event. This is not the case, however, because the nelsonite shows evidence of a weak foliation (mostly in form of oriented pyrite grains). It is interpreted that both the nelsonite and surrounding country rocks experienced regional metamorphism and deformation after the nelsonite intruded, but both deformation and metamorphism were much less pronounced in the nelsonite.
Small lenses (2 cm width) of nelsonite are locally observed in the surrounding metapelitic gneiss. One such lens occurring in rock excavated from the small hydroelectric plant on the Black River at the end of North St. was found to contain small (1 mm), highly fractured sapphires (Darling and Crysler, 2012). Their rich blue color is attributed to the presence of high amounts (up to 0.22 wt.%) of TiO2, which is not surprising given the composition of the host lens. Although these sapphires are not gem quality, their presence here demonstrates that conditions necessary to form sapphire did exist in the Adirondacks and that gem grade material may exist elsewhere.
OHM 2019: This is pretty far from where Darling put it on roadlogs in 1997 and 2000, but is close to where he put it in online sources (Minedat) correcting his 1995 paper.

STOP 3. Ordovician spheroidal weathering in Proterozoic gneiss
Walk down to the exposures of pink feldspathic gneiss along Roaring Brook. Here fractured bedrock contains very good examples of spheroidal weathering preserving between the fractures sets (Figure 4). The spheroidal weathering is characterized by closely spaced (3-4 mm) bands of iron hydroxide, the bands extending a few centimeters into the gneiss (from the fracture sets). Microscopically, the bands are characterized by fine-grained iron-hydroxide, calcite, chlorite, and possibly serpentine. Locally, the bands are filled with medium-grained calcite, suggesting open fracture deposition.
From this location, walk upstream about 30 meters and observe the lowermost strata of the Pamelia Formation (Middle Ordovician) resting directly on top of Proterozoic gneiss. This is the widely known Knox unconformity and is very well preserved in the stream bed. Spheroidal weathering also occurs directly below the non-conformable contact, but is observed only during low water levels (normally late summer). The spheroidal weathering directly below the nonconformity and ∼30 meters downstream (location of Fig. 4) are the only locations where it has been observed. Both are located within one vertical meter of the nonconformity. Exposures of felsic gneiss farther downstream, which are a few meters below the projection of the unconformity, show little or no evidence of spheroidal weathering. The proximal relationship between the nonconformity and the spheroidal weathering is interpreted as evidence of Ordovician-age chemical weathering. Middle Ordovician time, therefore, was likely tropical or sub-tropical, which is consistent with paleomagnetic studies (Niocaill, et al., 1997).
Because the closely spaced bands of iron hydroxide (in the spheroidal weathered portion of the gneiss) contain chlorite, the rocks must have been buried to “chlorite-grade” depths following middle Ordovician deposition. This is interpreted to have occurred during the late Paleozoic Alleghanian Orogeny (Isachsen et al., 1991). Consequently, the chlorite cannot be associated with any retrograde metamorphism that occurred during exhumation of Proterozoic rocks following the Grenville Orogeny.

LUNCH and Restroom Stop

Former Lyons Falls Pulp & Paper Co. on left; Gould Mansion on right.

Site of former "three-way bridge" of Lyons Falls

STOP 4. Two-pyroxene amphibolite at Lyons Falls
Lyons Falls drops about 63 feet here and has been harnessed as a power source since the mid-1800’s. The base of the falls served as an initial settlement for French explorers of the “Castorland Company,” in June of 1794 (Hough, 1860).
Lyons Falls occurs here because of a ∼100 meter wide band of highly resistant amphibolite gneiss that strikes SW-NE, normal to the course of the Black River. The amphibolite here is strongly lineated with discontinuous, thin, plagioclase-rich bands. Foliation is poorly developed. The unit has a sharp contact with quartz-feldspar gneiss to the south (observed at the foot of the upstream board dam) but the north contact is not exposed.
Petrologically, the unit is best described as a medium-grained, two-pyroxene amphibolite. Hornblende and plagioclase are the dominant mineral phases. A red-brown (presumably Ti-rich) biotite and opaque magnetite occurs as well (Figure 5). Unlike the central and eastern Adirondacks, the amphibolite at Lyons Falls contains no garnet, despite the fact they are compositionally similar.
The absence of garnet in amphibolites from the western Adirondacks has been known for a long time (Buddington, 1939; de Waard, 1967 and references therein). Its absence is due to lower metamorphic pressures in this region of the Adirondacks as compared to the central and eastern Adirondack Highlands. Figure 6 shows that the amphibolite of Lyons Falls is located to the west of the garnet + clinopyroxene isograd. In mafic rock compositions, this isograd is based on the reaction:
orthopyroxene + anorthite = clinopyroxene + garnet + quartz (1),
where garnet is present on the higher pressure side of the reaction. The famous garnet amphibolites (e.g. Gore Mtn.), so common in the central and eastern Adirondacks could not form in the western Adirondacks simply because the rocks were not buried deep enough.
Also occurring at Lyons Falls are some meter-scale potholes carved into the amphibolite. These are best observed during low-water levels and closer to the water fall.

STOP 5. Undeformed pegmatite and hydrothermal sillimanite + quartz veins in Lyon Mtn. granite.
This stop demonstrates important igneous and hydrothermal features of Lyon Mtn. granite along the Moose River. These exposures were studied extensively by McLelland et al. (2001, 2002a, 2002b) and Selleck et al. (2004). Their overall interpretation is that Lyon Mtn. granite experienced contemporaneous intrusion and hydrothermal alteration at about 1035 Ma. The hydrothermal activity leached large cations (K+, Na+) from the granite but left behind Al3+ and Si4+ to form quartz-sillimanite veins. Early vein sets were ductily deformed (due to magmatic flow or tectonic shear) and younger veins sets formed afterward.
These rocks were included in a large unit of mapped metapelites in Figure 1 of Florence et al. (1995) but the composition and textural features are more consistent with igneous rocks. Some of the country rocks into which the Lyon Mtn. granite intruded are indeed metapelites, and numerous exposures of sillimanite + garnet + hercynite + quartz + K-feldspar gneiss occur in the area.
Looking west from the bridge on the northern side of the Moose River, one can observe an undeformed pegmatite cutting hydrothermally altered Lyon Mtn. granite. The pegmatite is shown in Figure 7 and is compositionally zoned with an uncommon magnetite-rich core. McLelland et al. (2001) dated well-zoned igneous zircons from this pegmatite at 1034 ± 10 Ma. Because the pegmatite is undeformed, the 1034 Ma zircon age has been interpreted as the terminus of Ottawan deformation in the Adirondacks (Orrell and McLelland, 1996).
The bedrock exposed farther downstream show excellent examples of quartz + sillimanite veins hosted by Lyon Mtn. granite (see Figure 8). These veins occur in two prominent orientations, N20E and N50E (McLelland et al., 2002a). At other locations in the area (e.g. Ager’s Falls), the quartz-sillimanite veins are nodular in shape and strongly deformed (McLelland et al., 2002a,b).

1876 red school house on right.

STOP 6. Moose River Prismatine locality
Follow the all-terrain vehicle path downstream for about 200 meters. The path passes through the stone foundations of the former Moose River tannery and then follows rapids as the Moose River flows southwest. Here, the river cuts through northwest-dipping, calcsilicate gneisses and quartzites. Stay high on the river bank until the rapids disappear. The path will descend and cross a small, wet, muddy creek bed. Afterwards, the Moose River pools and turns north and the first outcrops on the west side of the river are the prismatine-bearing rocks. Please exercise caution while walking among the river boulders and talus at the base of the outcrops. Also, please DO NOT USE HAMMERS at this stop and refrain from collecting prismatine specimens unless you’re planning to study them scientifically; a future geologist will be grateful someday.
Prismatine, the boron-rich end member of the kornerupine solid solution (Grew et al., 1996; ideally Mg3Al6Si4BO21(OH)) occurs in metapelitic and quartzitic rocks along the Moose River. Kornerupine-group minerals are generally rare, having been described from nine localities in the Grenville Province (Grew, 1996; Darling et al., 2004; Korhonen and Stout, 2005) including two in the Adirondacks (Farrar and Babcock, 1993; Farrar, 1995; Darling et al., 2004).
Along the Moose River, prismatine occurs at two locations (separated by about 400 meters, Figure 10) within a unit of heterogeneous metasedimentary rocks (Figure 10, unit BL) mapped by Whitney et al. (2002). This unit comprises mostly quartzite and biotite-quartz-plagioclase gneiss with lesser amounts of calcsilicate rocks, and minor amphibolite, quartzofeldspathic gneiss, and calcite marble (Whitney et al., 2002). These rocks are interlayered with other metasedimentary and meta-igneous rocks (Figure 10). These units occur in a complex, southeast-verging overturned synform bordered on the northwest by a tabular, northwest-dipping body of charnockitic gneiss (CG) several kilometers thick, and on the southeast by a domical body of batholithic proportions consisting of relatively leucocratic CG (Whitney et al, 2002). Although the granitic and charnockitic rocks have not been dated, they are lithologically and geochemically similar to felsic rocks of the ca. 1150 Ma anorthosite-mangerite-charnockite-granite (AMCG) suite found throughout much of the Adirondack Highlands (McLelland et al., 2001; Whitney et al., 2002).
In addition to prismatine-bearing assemblages, the surrounding rocks contain metapelitic assemblages of a) cordierite + spinel + sillimanite + garnet + plagioclase + quartz + ilmenite + rutile ±biotite, b) cordierite + orthopyroxene + biotite + K-feldspar + quartz, and c) orthopyroxene + plagioclase + K-feldspar + quartz +/- biotite, ± garnet (Darling et al., 2004).
The feature of geologic interest at STOP 6 are the exceptionally well-developed prismatine crystals in coarse-grained, feldspathic lenses. Here, prismatine crystals form dark greenish-black, euhedral, elongated grains (up to 10 cm in length). Ed Grew (personal communication) indicates that only the prismatine crystals from the Larsemann Hills, Antarctica (Grew and Carson, 2007) are comparable in length to those at Moose River. The prismatine commonly displays radiating patterns in feldspathic lenses one to three cm thick (Figure 11A).
The prismatine crystals appear to have grown only within the plane of the foliation. However, upon closer examination, the prismatine grains are seen to be arranged randomly, but the longest and best-developed crystals formed parallel to the foliation plane. Because of this, Darling et al. (2004) inferred that nondeviatoric pressure conditions prevailed locally during prismatine formation. It should also be noted that a number of prismatine-bearing feldspathic lenses are located adjacent to fine-grained tourmaline + plagioclase + biotite–rich zones near the north end of the exposed rocks. In these locations, the prismatine-bearing feldspathic lenses texturally embay, cross-cut earlier foliation, and appear to form at the expense of the tourmaline-bearing zones (Figure 11B). The embayed country rocks, coarser grain size, and the random arrangement of the prismatine crystals led Darling et al. (2004) to interpret the feldspathic lenses and the prismatine found in them to be of anatectic origin.
Plagioclase, K-feldspar, minor quartz and rutile are the most common phases associated with prismatine, but biotite, cordierite, garnet and rarely sillimanite occur locally as well. The prismatine contains 0.73 to 0.79 formula units of B (out of 1.0) and has Mg / Mg + Fe between 0.70 and 0.73 (Table 3 of Darling et al., 2004). After determining the associated mineral compositions, Darling et al. (2004) proposed the following prismatine-forming reaction:
Tourmaline + sillimanite + biotite + cordierite → prismatine + rutile + melt (2).
Reaction 2 is similar to a number of proposed prismatine-forming reactions from other granulite terranes (Grew, 1996), including those in sapphirine-free rocks found in the Reading Prong, New Jersey (Young, 1995), and in Waldheim, Germany (Grew, 1989). In those cases, garnet rather than cordierite was a proposed reactant.
Metamorphic temperatures and pressures are difficult to estimate from prismatine-bearing mineral assemblages as little is known about the stability of boron-rich kornerupine at pressures less than 10 kb (Schreyer and Werding, 1997). However, the prismatine occurs in proximity to low-variance metapelitic assemblages in the surrounding rocks. Specifically, thermobarometry calculations from net transfer and exchange equilibria record temperatures and pressures of 850° ± 20°C and 6.6 ± 0.6 kilobars for orthopyroxene + garnet assemblages and 675° ± 50°C and 5.0 ± 0.6 kilobars for cordierite + garnet + sillimanite + quartz assemblages (Darling et al., 2004). The former assemblage is interpreted to have formed during partial melting whereas the latter assemblage is interpreted to have formed on the early retrograde metamorphic path (Darling et al., 2004). The ∼850°C temperatures derived from the orthopyroxene + garnet assemblage are reasonable for partial melting conditions. Although the cordierite + garnet + sillimanite + quartz assemblage occurs at STOP 6, it and the orthopyroxene + garnet assemblage are better developed farther downstream at the second prismatine location (the westernmost open circle in Figure 10). These exposures can be reached by following the footpath on the south bank of the Moose River for a distance of about 400 meters.
Because many of the prismatine-bearing feldspathic lenses are saturated in both quartz and rutile, Storm and Spear (2009) intensely studied the prismatine-bearing lenses as part of a natural test of the titanium-in-quartz geothermometer of Wark and Watson (2006). Storm and Spear (2009) determined a wide range of metamorphic temperatures, specifically from 630 + 63 / -86 to 879 ± 8 °C, but most determinations fell between 700°C and 880°C (see Figure 8a of Storm and Spear, 2009). This is in good agreement with metamorphic temperatures determined by the aforementioned methods (Darling et al., 2004). Storm and Spear (2009) also provide convincing textural evidence that prismatine was locally replaced by leucosomatic quartz, most likely during melting of prismatine. Interestingly, it was the leucosomatic quartz that yielded the highest Ti-in-quartz temperatures (800-880°C; Figure 8a of Storm and Spear, 2009).
The age of partial melting is unknown at this time but is likely associated with either intrusion of the AMCG suite at ∼1160-1145 Ma, or burial associated with the Ottawan phase of the Grenville Orogenic cycle and the associated intrusion of Lyon Mtn. granite at ∼ 1050-1030 Ma (McLelland et al., 2010).

A2: QUATERNARY GEOLOGY OF THE ONEIDA LAKE BASIN
Eugene W. Domack,
Hamilton College, Clinton, NY
edomack@hamilton.edu
Madhav Krishna and Lewis A. Owen
University of Cincinnati, Cincinnati, OH
Dale P. Hess, Brock University
St. Catharines, Ontario, Canada
Todd W. Rayne and David A.Tewksbury
Purpose:
The purpose of today's field excursion is to introduce you to the diversity of landforms and processes acting upon the landscape of the eastern end of Oneida Lake. The content is intentionally not exhaustive. However, we will examine one of the the most dynamic landscapes in New York State, learn of the natural history, and discuss human induced alterations that have taken place in the last hundred years. The summary presented in this field guide represents over 10 years of work by Hamilton College Students (Hiscott, 2000,; Fadem, 2001; Cleary, 2002; Arnold, 2004; Fung 2008; Houlden, 2008; Talia-Murray, 2010 and others in progress) and a collaborative study with the Madison county planning Dept. (Scott Ingmire) via grants from NYS-DEC to CNYRPDB. Our work is ongoing and we hope to have more to contribute in the years to come. We will attempt to visit 7 stops this afternoon; some are no more than way points on our travels others are deserving of more comment, and, hopefully, discussion.

A2: QUATERNARY GEOLOGY OF THE ONEIDA LAKE BASIN
E.W.Comack, M.Krishna, L.A.Owen, D.P.Hess, T.W.Rayne, D.A.Tewksbury

STOP 1. Irish Ridge Road, grounding line moraine.
Here at Grove Cemetery we can view the last of the glacial margins of the Ontario Lobe of the Cordilleran Ice Sheet, as marked by Irish Ridge Road Moraine. Irish Ridge is cored with stratified sand and gravel and is likely much longer than its apparent trend from the map alone. This is because it is buried by overlying lake sediments of Glacial Lake Iroquois to the north and south. The ridge served as a temporary grounding line of the retreating ice sheet as indicated by the steep (up-ice) western side, and the more gentle (down-ice) eastern side. The internal structure of the ridge is revealed by ground penetrating radar which shows a series of foresets, (dipping reflectors) of sand and gravel that indicate material being shed to the east, off the glacial margin as it stood in a proglacial lake, proto Glacial Lake Iroquois.
E.W.Comack, M.Krishna, L.A.Owen, D.P.Hess, T.W.Rayne, D.A.Tewksbury

STOP 2. Reticulated ground moraine with rhombohedral ridge pattern.
We will walk over to the top of the linear ridge which runs oblique to the road and have a discussion.
E.W.Comack, M.Krishna, L.A.Owen, D.P.Hess, T.W.Rayne, D.A.Tewksbury

STOP 3. Rome Sand Plains, parabolic dune complex
Proceed to the excavation dug into the forested hill side directly northwest from the parking area.
After discussion and examination of the sedimentary structures return to the vehicles.

STOP 4. Kame terrace, glaciofluvial deposits
We have permission to examine, excavate, and sample if we wish. This is a great stop for sedimentary structures so bring your cameras.

STOP 5. Barrier beach spit complex Glacial Lake Iroquois ? shoreline.
Some discussion will follow here and examination of deep excavation into fossiliferous gravels.
The forested landscape here is deceiving as this once was the eastern extent of Glacial Lake Iroquois; the prominent set of ridges is today covered by relict dunes, old growth white pine, beech, oak and maple. The beach ridge landforms extend to both sides of the Fish Creek - Barge Canal waterway as can be seen in topographic maps and on air photographs (see cover). We have only completed detailed work on the easternmost set of ridges and those south of the Fish Creek divide. Between the ridges are wetlands that were once bays, protected from the open lake by the beach ridges which stood 20' above paleo lake level. Excavations and ground penetrating radar indicated sediment layers that dip both to the west (the shore face) and to the east (over wash). Grain size of the beach material is much coarser than the modern day beach sand, likely reflecting the direct derivation of the former from underlying glacial sediment. Within these sand and gravels large shell fragments can be found, including the species:
Lasmignoa compressa
Sphaerium simile, (Grooved Fingernail Clam) and
Helisoma campanulatum campanulatum.
Radiocarbon dates on these shells range from 10,990 ±40 to 9,760±40, thus providing one of the oldest sets of radiocarbon ages from this part of New York (Fadem, 2001). The two most prominent ridges likely started as spits, growing northward across the lake bay system. The are also the only ridges to be capped by a thick eolian dune system of well sorted medium grained sand.

STOP 6. Second ridge complex with eolian dune complex superimposed.
Some discussion will follow here.

STOP 7.Sylvan Beach headland, mouth of Fish Creek and Barge Canal
If it is windy we may relocated to a more sheltered location.
Here we will summarize and discuss the evidence for lake level fluctuations and the evolution of Lake Iroquois to Oneida Lake from seismic reflection and core work in modern Oneida Lake. We will also discuss the last century of shoreline modification and environmental issues related to the installation of the NY Stat Barge Canal.
Fish Creek is a large continuously flowing stream that drains the Tug Hill Plateau and the Rome Sand Plains to the NE. It is a bed load river with a dominant sand sized load. In the past the river was the major migratory path for Atlantic Salmon and other fish, but today it's far less important. Since 1838 there have been a number of interruptions in the normal flow of water from either Fish Creek or Wood Creek as various canals (Oneida Lake Canal, Erie Canal, and now New York State Barge Canal) intersected the waterways some distance east of the lake shore. Hence the natural base level of the two creeks was at various time, and is now, at the juncture of the canal and the streams, not the lake. The sandy bed load is thus deposited locally at the conjunction of the three waterways, making dredging necessary every other year.

A3: PEGMATITES OF NEW YORK STATE: THE BATCHELLERVILLE PEGMATITE
Abigail R. Seadler
American Geosciences Institute, Alexandria, VA 22302
arseadler@gmail.com
Marian Lupulescu
New York State Museum, Albany, NY 12230
mlupules@mail.nysed.gov
David G. Bailey
Hamilton College, Clinton, NY 13323
dbailey@hamilton.edu
INTRODUCTION
Despite their interesting petrographic features, geological associations, and mineral assemblages, there are only a few modern scientific studies on the pegmatite bodies of New York State (Tan 1966; Putman and Sullivan 1979). The pegmatites are found in two geological units: the Grenville-age (1300 - 1000 Ma) metamorphic rocks of the Adirondack Mountains (Figure 1) and the Taconic-age (∼ 450 Ma) metamorphic rocks of southern New York. There are approximately 25 significant pegmatite bodies known in New York, and they can be placed into six different geologic / geographic groups:
A. The Bedford pegmatite district consisting of the amazonite- and the peristerite-bearing pegmatites at Valhalla in Westchester County, and the small pegmatite bodies in the Taconic-age metamorphic rocks of the Manhattan Prong (New York City) that are xenotime, or beryl- and chrysoberyl-bearing;
B. The Cranberry Creek (Mayfield), Batchellerville, Greenfield, Day (Overlook), and Corinth belt of pegmatites in the southern Adirondack Highlands;
C. The Crown Point, Rose Rock, Spar Bed Hill, Chestertown, and Fort Ann pegmatites in the central-eastern Adirondack Highlands;
D. The Scott Farm - Benson Mines pegmatite belt in the northwestern Adirondack Highlands;
E. The Lyons Falls and Stiles Farm pegmatites in the western Adirondacks; and
F. The McLear and other small pegmatite bodies in the Adirondack Lowlands.
HISTORY
General
Interest in the pegmatites of New York started with the rush to find and mine high-quality feldspar in the second half of the nineteenth century. The second stage for pegmatite exploration began in 1950 when the USGS initiated a nationwide search for uranium resources. The first attempt to mine pegmatites in New York State began around 1878 at the Bedford pegmatite. Mining at Bedford lasted until 1949, and in 1962 and 1963 the dumps and most of the mine structures were leveled to build houses (Tan 1966).
The pegmatites in the east central Adirondacks were first mined for enamel, crushed stone, grit for chicken feed, and on a smaller scale, for quartz used in glass manufacturing. Mining began in the late nineteenth century and lasted until around 1926 (Tan 1966).
In the northwestern Adirondacks, the McLear pegmatite was discovered in 1907. Here, feldspar was found in high-quality masses 6 in to 3 feet in length with no iron staining, but with rare grains of pyrite as inclusions. The quarry was worked by the White Hill Mineral Company until 1937, and after that, by the Green Hill Mining Company. The feldspar that was mined was shipped to Trenton, New Jersey, and used in the ceramics industry. The mine was closed around 1938 (Tan 1966).

A3: PEGMATITES OF NEW YORK STATE: THE BATCHELLERVILLE PEGMATITE

STOP 1a. The "Lower Pit"
**NOTE: The Batchellerville pegmatite is on private property; trespassing is not allowed!/font Permission is required before entering the property for any reason. We are extremely fortunate that the landowner has allowed us to access the site for this field trip. Please do not jeopardize the possibility of future trips for scientific research by trespassing and/or any large-scale mineral collecting activities.

STOP 1b. The "Big Pit"

STOP 1c. The "Garnet Pit"

A5: A CENSUS OF DEVONIAN LIFE IN CENTRAL NEW YORK STATE: FOSSIL COLLECTING FOR TEACHERS AND STUDENTS
Constance M. Soja
Department of Geology, Colgate University, Hamilton, NY 13346
csoja@colgate.edu
Cynthia R. Domack
Department of Geosciences, Hamilton College, Clinton, NY 13323
cdomack@hamilton.edu
Richly fossiliferous rocks of Middle Devonian age (375 million years old) are exposed near Hamilton, NY, and represent some of the most complete fossil-bearing sequences that formed during this time period anywhere in the world. The shale we will examine was deposited at a time when the Acadian Mountains (precursor of the younger Appalachian Mountains) were forming in eastern New York state (present day Catskills Mountains area) as a result of collision between a microcontinent and eastern North America. Uplift and mountain building resulted in extensive erosion and transport of sediment towards Hamilton where these materials accumulated. As the fossils below indicate, the shallow epicontinental (epeiric) sea that once covered central New York State had abundant, teeming life.
Our goal during the field exercise is to accumulate as much information as possible to complete a detailed "census" and paleoecological analysis of the fossils. Upon arrival at the field site, participants will draw specialist roles from a hat and work in small groups collecting fossils. Time will be allotted for specialists to work together compiling data before our group discussion. We will brainstorm questions that paleontologists can ask and answer about the fossils preserved at the field site. Participants will depart the field site appreciating the diversity of life that existed in central New York State during the Devonian and the environmental conditions that were conducive to exquisite fossil preservation.
Field Trip Schedule
12:00 noon—group departs Hamilton College for fossil site near Lebanon Reservoir (32 miles + one quick restroom stop = 1 hour)
1:00 pm—bus arrives at fossil locality
1:00-1:15 pm—welcome and orientation
1:15-2:15 pm—group collects fossils in specialist teams
2:15-3:00 pm—each team compiles fossil data
3:00-3:45 pm—group discusses data and makes interpretations
3:45-4:00 pm—Q&A, participants pack up samples
4:00 pm—group departs Geer Road (+ one quick restroom stop)
5:00 pm—group arrives at Hamilton College
A fossil guide (Some Common Invertebrate Macrofossils of the Hamilton Group of Central New York modified by C. M. Soja) will be provided to each participant.

Geer road Quarry

A7: SILICIC APPALACHIAN MAGMATISM DURING THE ORDOVICIAN AND DEVONIAN: PERSPECTIVES FROM THE FORELAND BASIN, AND THE HINTERLAND
Charles Ver Straeten
New York State Museum and Geological Survey, 3140 Cultural Education Center,
Albany, NY 12230 cverstra@mail.nysed.gov
Gordon Baird
Department of Geosciences, SUNY Fredonia, Fredonia, NY 14063 Baird@fredonia.edu
Paul Karabinos
Geosciences, Williams College, Williamstown, MA 01267
Paul.M.Karabinos@williams.edu
Scott Samson
Earth Sciences Department, Syracuse University, Syracuse, NY 13244-1070
sdsamson@syr.edu
Carlton E. Brett
Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013
carlton.brett@uc.edu
INTRODUCTION
At times, viscous, silica-rich molten rock in the upper portion of a magma chamber is forced upward and out of the chamber, through conduits to the surface, where volcanoclastic materials are explosively erupted through the mouth of a volcano and high into the atmosphere. Once buoyantly aloft, the extruded pumice, ash, crystals and rock fragments become sediments, and settle out close to and far from the volcano, blanketing any and all environments downwind. These airborne volcanic sediments may sometimes be transported thousands of kilometers from the source volcano by wind.
The history of explosive silicic magmatism on Earth is recorded in the plutonic and volcanic igneous rocks of their source areas, in volcanic and magmatic arcs; and in sediments, modern and ancient, downwind of their eruptive centers. Reconstruction of the history of silicic paleovolcanism, especially when the igneous source areas have been deeply eroded over deep geologic time (e.g., the Appalachian mountains), may be best determined through data from both hinterland (orogenic belt) igneous and foreland sedimentary rocks.
The purpose of this article and fieldtrip is, perhaps for the first time, to bring together a diverse team of geologists and their perspectives on regional silica-rich magmatic activity during the Ordovician and Devonian Periods – from both foreland sedimentary and hinterland igneous/tectonic records.
Following an overview of volcanic tephra processes from the magma chamber to final burial in sedimentary deposits (by Ver Straeten), Paul Karabinos will present a tectonic overview of the Appalachian hinterland during the low to mid Paleozoic, and compare data on volcanism of that time from the hinterland and foreland. Scott Samson then examines the materials in foreland basin volcanic layers that yield geochronologic, isotopic and geochemical data, which in turn yield an overview of the composition, source characteristics and petrogenetic origins of Ordovician magmas in eastern North America. Baird presents a detailed analysis and discussion of the sedimentologic, preservational, and diagenetic histories of Late Ordovician airfall volcanic layers in the Mohawk Valley. Finally, Ver Straeten lays out the time-stratigraphic occurrence of foreland basin tephra layers in the Devonian of the eastern U.S., and then provides an example comparing foreland basin and hinterland data from the Lower Devonian, with implications for possible igneous sources. In turn, the field trip will stop at four localities, to examine Ordovician and Devonian airfall volcanic “tephra” layers in sedimentary rocks, and feature similar discussions.
Various terms are utilized for the volcanoclastic products of explosive volcanism (e.g., tephra, ash, tuff, bentonite, K-bentonite, and others), as seen in this paper. The term “K-bentonite” is often applied to these Paleozoic volcanic layers. However, such beds may be not only K-bentonites, as seen at Stops 1 and 2. There they occur in three to four different states; as clay-rich K-bentonites, as phenocryst-rich tuffs, and as clay-poor calcite-cemented layers in which the original glass was apparently altered to zeolite minerals instead of clays. Rather than use multiple terms that actually describe their multifarious diagenetic and sedimentologic histories, it is perhaps best to recognize their shared volcanic origin – and call them “tephras”, the term chiefly utilized by modern and recent volcanologists for the products of explosive volcanism.
Technically, tephra consists of various components: volcanic glass fragments (= “volcanic ash”), pumice clasts, and crystals formed in the magma (“phenocrysts”), plus or minus country rock fragments. This is commonly termed “volcanic ash”, but as just noted, ash actually represents only the fine volcanic glass component of volcanoclastic materials. “Tuff” is commonly used for coarser-grained volcanoclastic deposits. “Bentonite” is clay-rich altered tephra, in which the glassy ash is altered to smectitic clays; in “K-bentonites” or “metabentonites”, clays are further altered to potassium-rich, mixed layer illite-smectite clays.

A7: SILICIC APPALACHIAN MAGMATISM DURING THE ORDOVICIAN AND DEVONIAN: PERSPECTIVES FROM THE FORELAND BASIN, AND THE HINTERLAND

Summit Lake to right

Upper strata of Ordovician Utica Fm. on left.

Przewtrzelski family, owners of Stop 1 (Pretzel Farm)
Przewtrzelski family, owners of Stop 1 (Pretzel Farm) at 121 Brookman Road

Utica Shale on left, and both sides ahead.

STOP 1. Airfall volcanic tephras in Upper Ordovician Utica Shale, at Pretzel Farm, Hallsville
An expanse of gently westward-dipping, Upper Ordovician, black Utica Shale floors Otsquago Creek at Stop 1 (See Figure 5). This exposure displays a portion of the lower part of the Indian Castle Member that is exceptional for the abundance of classic Utica fossils such as exuviae and carcasses of the trilobite Triarthrus, as well as abundant orthoconic cephalopods and graptolites belonging to the Climacograptus spiniferus biozone (see Goldman et al. 1994; Figure 5). Several important tephra beds are present in this outcrop; these will be examined in ascending order from the downstream (east) end of this section. We will examine a thin, calcareous tephra bed near the base of this section that contains abundant volcanogenic phenocrysts and sand-size pumice clasts preserved in partial 3-D relief along the base of the layer. A higher, partially cemented tephra bed will also be a focus of examination and questions (See Figures 5, 6c,d).

Utica fm / Dolgeville Fm contact
Contact of Ordovician-age Indian Castle Member (Utica Formation) and Dolgeville Formation in creek near red footbridge on right.

Road on right to type section of Valley Brook Shale Member
Road on right to type section of Valley Brook Shale Member, Flat Creek Formation, below Dolgeville Formation

Floral Avenue on right; access to lower Canajoharie Gorge.
Beekmantown Group carbonates, with large potholes, are succeeded upstream by Black River and Trenton Group carbonates.

Note flattening of road uphill,
Note flattening of road uphill, marking bedrock shift from carbonates to shales.

STOP 2. Airfall volcanic tephras in Upper Ordovician Flat Creek Shale, at Wintergreen Park, Canajoharie
This section lies in the upper part of the gorge of Canajoharie Creek, upstream from the village of Canajoharie (see Figure 4). This is a classic Utica Shale section that exposes the entire Flat Creek Shale Member succession as well as higher strata of the Dolgeville Formation, which are visible high in the gorge face across from our entrance point. Vertical joint sets in the hard, calcareous shale are spectacularly displayed in the bank walls and creek floor along our route.
We will focus on a tephra-rich interval downstream from our point of ingress (Figure 4). Strata examined here contain graptolites belonging to the Orthograptus americanus biozone (Goldman et al. 1994). We will first examine several tephras exposed a short distance downstream from the path entrance that can be easily identified from the rusty stain of sulfides weathered from these layers (Figures 4, 6). Most notable among these beds is a coarse tephra layer, informally designated the “sand band” (Baird et al. 1994), that may record an episode of submarine erosion or sedimentary condensation (Figure 6a,b). This bed underlies an interval of calcareous shale and impure limestone layers containing numerous fossils, including the distinctive hemispherical bryozoan Prasopora and the large trilobite Isotelus.
Proceeding downstream, the creek canyon makes two scenic bends. On a high, east-facing wall, a cluster of orange-weathering tephra bands is conspicuously displayed. We will proceed to a minimally-weathered part of this face to look at the apparent record of countless thin laminae that record possible, “average” or “small-scale” volcanogenic events that constitute Ordovician background volcanic activity.

Enter village of Sharon Springs
Enter village of Sharon Springs, an old spa resort town based on spring waters that surface here.

Classic Lower and Middle Devonian outcrops along Rte. 20
Classic Lower and Middle Devonian outcrops along Rte. 20 near Cherry Valley for next 0.6 miles. Strata include (east to west, and stratigraphically high to low) the Oatka Creek and Union Springs (=“Marcellus subgroup”), Onondaga, Schoharie, Esopus, Oriskany and Kalkberg formations.

Outcrops of Kalkberg Formation begin on right

STOP 3. Lower to Middle Devonian airfall tephra beds
Roadcuts on the south side of Rte. 20 east of Rte. 166 expose a long, nearly continuous section of the Lower Devonian Kalkberg, Oriskany, Esopus and Schoharie formations, and the Middle Devonian Onondaga Formation. Additional outcrops to the east expose the Union Springs and Oatka Creek formations (Marcellus subgroup of Ver Straeten 2007b). See Figure 13 for more details.
The Lower Devonian Kalkberg Formation, lowest in this section, features up to 15 thin volcanic airfall tuffs assigned to the Bald Hill K-bentonites (Smith et al. 1988; Shaw et al. 1991). Rickard (1962) reported the first tephra in this interval, visible just east of the overpass as a prominent crevice, filled with light gray to tan, soapy-feeling, sticky clay about one to two meters above ground level (Figure 9a,b). Additional K-bentonitic tephras occur in the Kalkberg Formation here.
The Bald Hill Tephra Cluster is reported from New York to Virginia and West Virginia Rickard’s original bed from Cherry Valley was dated by Tucker et al. (1998) at 417.6+1.0 Ma (207Pb/206Pb, zircons). Silicic volcanic and plutonic rocks with overlapping age dates and biostratigraphy are found in Maine and maritime Canada Up the road, lower strata of the Esopus Formation here consist of 4.4 m of interbedded cherts, K-bentonites, shales and minor thin sandstones (Spawn Hollow Member). Fifteen 1 to 14 cm-thick clay to claystone layers with zircons, apatites, and other phenocrysts indicative of a volcanogenic origin (Sprout Brook K-bentonites) occur within the lower 3.6 m of the outcrop (Ver Straeten 2004b; Figure 9c). The site, now largely covered, is the type section of the Sprout Brook K-bentonites. Tephras of the Sprout Brook cluster are known only from eastern New York (Figure 9c-f). Two Sprout Brook beds from Cherry Valley were dated by Tucker et al. (1998) at 408.3+1.9 Ma (207Pb/206Pb). A number of silicic plutonic and volcanic rocks with dates that overlap that of the Sprout Brook K-bentonites are found in the northern Appalachians (e.g., the co-magmatic Katahdin Granite and Traveler Rhyolite, north-central Maine; Ver Straeten 2010; Figure 11).
Hanson (1995) reported a thin, discontinuous K-bentonite at the erosional base of the overlying sand-rich Schoharie Formation here (Carlisle Center Member). Another glauconite- and phosphate-rich clay bed marks the base of the Onondaga Limestone at Cherry Valley (Figure 10c). Best seen when dug out on the north side of Rte. 20 west of Rte. 166, the bed features a mix of detrital, authigenic, and volcanic grains (Ver Straeten 2004a).
Additional clay-dominated tephra beds occur through the lower three members of the Onondaga and equivalent units around the Appalachian basin. Most of these are difficult to find in relative shallower water facies in eastern New York, including at Cherry Valley.

Elongate outcrop of Seneca Member on right.
Black shales of Bakoven Member (Union Springs Formation, Marcellus subgroup) in covered slope above, capped at break in slope by Hurley and Cherry Valley members of the overlying Oatka Creek Formation (Marcellus subgroup).

STOP 4. Airfall tephra beds of the Middle Devonian Tioga A-G cluster
Upper limestones of the Onondaga Formation (Figure 13) are found in this and nearby roadcuts. Topmost Moorehouse Member strata are visible on the north side of Rte 20. Two meters of the overlying Seneca Member represent the full thickness of the member locally.
The Tioga B Tephra, at the base of the Seneca Member, occurs in a deep reentrant near the base of this outcrop (Figure 10a,b). The Tioga B (anomalously thin at 12 cm here) is correlatable throughout most of the Appalachian Basin, except near Albany, and in central Ohio (Ver Straeten 2004a, 2007b).
A second thin K-bentonite, found in a crevice 0.73 m above the Tioga B is also found widely around the Appalachian Basin. A third K-bentonite was dug out 2.0 m above base of the Tioga B, at the Onondaga-Union Springs (Marcellus) contact 0.3 miles east of Stop 4.
The Tioga A-G K-bentonites occur throughout the Appalachian Basin; one of the beds has been reported from as far west as Illinois (Collinson 1968). The Middle Devonian Tioga- B K-bentonite was dated by Roden et al. (1990) at 390.0+0.5 Ma.

B1: KIMBERLITIC ROCKS OF NEW YORK STATE: THE DEWITT “KIMBERLITE”
David G. Bailey
Hamilton College, Clinton, NY 13323
dbailey@hamilton.edu
Marian V. Lupulescu
New York State Museum, Albany, NY 12230
mlupules@mail.nysed.gov
One of the very first scientific descriptions of a kimberlite was published in 1839 by Lardner Vanuxem in his third annual report on the geology of central New York State (Vanuxem 1839). The locality and samples he described were from the city of Syracuse, and were provided by the Principal of the Syracuse Academy, Oren Root (Williams 1887a, b). These early samples all came from a cluster of complexly related small intrusions in the northern portion of the city (Figure 1). Vanuxem (1842) described these rocks as part of “a great mass” of “well characterized serpentine” containing “particles of a yellow or golden color” (phlogopite) and “others of the red color of blood-stone” (pyrope). These intrusions received moderate scientific interest over the next thirty years as geologists struggled to understand the presence of these unusual rocks in the middle of the flat-lying Paleozoic sedimentary sequence of upstate New York (Dana 1878; Geddes 1860; Hunt 1858). Following the breakthrough work of Lewis (1887), who was the first to recognize that serpentinized, mica-bearing peridotites were the source rocks of gem diamonds in South Africa, the interest in the kimberlitic rocks of central NY increased dramatically. Over the next twenty years, numerous scientific reports (Clark 1908; Clarke 1899; Darton and Kemp 1895; Kraus 1904; Schneider 1902, 1903; Williams 1887b) and stories in local newspapers ("Gems here at home" 1906; "Syracuse has diamond hunt" 1905; "Would advance cash to probe stratums" 1902) were published on the Syracuse kimberlites.

STOP 1. The Dewitt “Kimberlite”
Park near the LeMoyne College Physical Plant, and follow the well-maintained trails to the slopes of the reservoir. Centimeter to meter-scale blocks can be found in the woods along the slopes of the reservoir. Please do not dig or excavate large blocks from the slopes! We will examine a number of specimens and discuss the mineralogy and petrology of the intrusion.

B2: HYDROGEOLOGY OF A SAND AND PEAT AQUIFER, ROME SAND PLAINS, NEW YORk
Todd W. Rayne
Hamilton College, Clinton, NY 13323
trayne@hamilton.edu
The Rome Sand Plains is a mosaic of sand dunes, bogs, pine barrens, meadows, and deciduous forest that covers 16,000 acres in Oneida County, New York (Russell 1996). The area is one of the few remaining inland pitch pine barrens in the northeastern United States and is partly protected by a consortium of government agencies and conservation groups. The field site for this trip is located approximately 4 miles west of the city of Rome, New York, on Hogsback Road (Figure 1).
The field site is an area of parabolic dunes with an adjacent peat bog (Figure 2). There is approximately 50 feet of relief between the dune crests to the flat bog surfaces. The dunes were formed on what was probably a kame terrace that was about 50 feet above the surrounding lower area to the north (Eugene Domack, oral communication, 2012). When the ice melted, sand on the terrace surface was reworked by prevailing westerly winds into a series of parabolic dunes (Figures 2 and 3). The dunes are composed of fine to medium sand with a Fe hydroxide coating that gives it a yellowish color. The low areas between the dunes became bogs, partly because of a high water table that inhibited the growth of larger plants. The bogs are dominated by Sphagnum moss and a variety of distinctive plants such as bog rosemary and leatherleaf (Russell 1996). There are also sundew and pitcher plants in some bogs, but we probably won’t see any on our trip. Peat thickness ranges from less than 1 m in bogs that were mined for peat to ~8 m in undisturbed bogs. Water in the peat is acidic, with a pH of 4 to 5.

Rome Sand Plains - Parabolic Dunes and Peat Bog
The field site is an area of parabolic dunes with an adjacent peat bog (Figure 2). There is approximately 50 feet of relief between the dune crests to the flat bog surfaces. The dunes were formed on what was probably a kame terrace that was about 50 feet above the surrounding lower area to the north (Eugene Domack, oral communication, 2012). When the ice melted, sand on the terrace surface was reworked by prevailing westerly winds into a series of parabolic dunes (Figures 2 and 3). The dunes are composed of fine to medium sand with a Fe hydroxide coating that gives it a yellowish color. The low areas between the dunes became bogs, partly because of a high water table that inhibited the growth of larger plants. The bogs are dominated by Sphagnum moss and a variety of distinctive plants such as bog rosemary and leatherleaf (Russell 1996). There are also sundew and pitcher plants in some bogs, but we probably won’t see any on our trip. Peat thickness ranges from less than 1 m in bogs that were mined for peat to ~8 m in undisturbed bogs. Water in the peat is acidic, with a pH of 4 to 5.

B2: GEOMICROBIOLOGY OF A MEROMICTIC LAKE, GREEN LAKE, FAYETTEVILLE, NEW YORK
Michael L. McCormick
mmccormi@hamilton.edu
Meromictic lakes are composed of stratified non-mixing and geochemically distinct water bodies. The lack of annual turnover (meromixis) normally results in the depletion of oxygen in the bottom waters (monimolimnium) and a complementary limitation in nutrient return from sediments to surface waters (mixolimnium). Green Lake, located close to Fayetteville, New York, was the first meromictic lake described in North America (Eggleton, 1931). The earliest report of Green Lake (then named Lake Sodom) dates to 1839 in which the white marl that lines the shores and coats fallen trees was well described (Vanuxem, 1839). A decade later, the first qualitative geochemical assays of Green Lake confirmed the presence of hydrogen sulfide in the lake’s bottom water (Clark, 1849). An excellent review of the early Green Lake literature, which spans 150 years, is provided by Thompson et al. (1990). This long record led Thompson to speculate that Green Lake may be the most well studied meromictic lake in the world. While this may be true with regard to the geology and limnology of Green Lake, much remains unknown about the lake’s microbial ecology and biogeochemistry. Here I provide an overview of historic and recent work that addresses the relationship between Green Lake’s microbial communities and its remarkable geochemical features. I also describe a low cost method developed for acquiring aseptic samples at high spatial resolution and present partial results from a survey of microbial community composition and geochemistry throughout the water column of Green Lake using this technique.

STOP 1. Green Lakes State Park - Deadman's Point
Although the precise origins of Green Lake and its close neighbor Round Lake are debated, they are most commonly reported to have formed as waterfall plunge basins during the last glacial retreat (∼13,000 years ago) (reviewed in Hilfinger and Mullins, 1997). The basins of both lakes penetrate the Syracuse and Vernon formations and lie in an east-west oriented glacial melt water channel (Sissons, 1960). The lakes were privately owned until 1927, when the surrounding land was purchased by New York State to create Green Lakes State Park (New York State Office of Parks, 2004). Green Lake itself is shaped something like a comma, the central basin being nearly circular with a drainage channel to the northeast forming the comma’s tail (Figure 1). The lake is 55 m at its deepest point, has a small surface area (0.26 km2) and is surrounded by steeply rising hills to the northwest and southeast. These features (depth, small surface area and wind shelter) all contribute to the lake’s meromixis. The lake’s present elevation is 127 m, approximately equal to the Erie Canal, which lies just north of the park. The majority of recharge to Green Lake is comprised of ground water that enters the monimolimnium after percolating through the Syracuse Formation and Vernon Shale. The ground water is saline and contains high concentrations of Ca2+, Mg2+ and SO42- attributed to the dissolution of dolomite (CaMg(CO3)2), gypsum (CaSO4•H2O) and halite (NaCl) deposits (Thompson et al., 1990; Torgersen et al., 1981). This saline input sufficiently increases the density of the monimolimnium relative to the mixolimnium to establish stratification, thus Green Lake is a classic example of crenogenic meromixis (Bradley, 1929; Eggleton, 1956; Takahashi et al., 1968). To close hydrologic, isotopic and chemical balances on the lake, Takahashi et al. (1968) argued that a separate less saline ground water input must also enter the mixolimnium. A model of two ground water inputs was supported by the stratigraphic and sedimentological studies of Thompson et al. (1990) who suggested a shallow seep enters the mixolimnion along the Syracuse-Vernon contact (∼10 m depth) and a deeper more saline input enters along the contact between the green and red units of the Vernon Shale (∼18 m). This lower seep occurs at approximately the same depth as the chemocline, the transition zone lying between the mixolimnium and monimolimnium, marked by dramatic gradients in oxidized and reduced chemical species and a notable dense population of purple sulfur bacteria (Figure 2).

B5: IRONSTONES, CONDENSED BEDS, AND SEQUENCE STRATIGRAPHY OF THE CLINTON GROUP (LOWER SILURIAN) IN ITS TYPE AREA, CENTRAL NEW YORK
Nicholas Sullivan
[nsullivan742@gmail.com]
Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013
Carlton E. Brett
[brettce@ucmail.uc.edu]
Patrick McLaughlin
[pimclaughlin@wisc.edu]
Wisconsin Geological and Natural History Survey, 3817 Mineral Point Rd., Madison, WI 53705
ABSTRACT
The fossiliferous and oolitic ironstones of the Clinton Group (Silurian, late Llandovery to early Wenlock) in central New York have inspired considerable interest since the early surveys of Eaton in the 1820s. Although these ores have never been mined on industrial scales, they were processed extensively up to the mid 1900s for oxides used in red paints. Three of these horizons, Westmoreland, "basal Dawes" or Salmon Creek, and Kirkland, will be examined and discussed on this excursion, with emphasis placed on their sedimentology, taphonomy, correlation, and regional significance in the context of depositional cycles.
Recent work has recast these classic deposits in the context of sequence stratigraphy, wherein ironstones and related phosphatic and shelly deposits are viewed as condensed facies: the product of siliciclastic sediment starvation during periods of rapid transgression at the bases of small- and large -scale depositional sequences. These strata and the environmental conditions they represent will also be considered in the context of recently collected geochemical and geophysical data, which have implications for the correlation of these sections and their importance with regard to regional and global environmental changes and bioevents.
Although iron rich horizons in the sedimentary record are the subject of numerous studies, many critical questions remain concerning the processes of their formation (see Van Houten and Bhattacharyya, 1982; Kimberley, 1994 and references therein). Ferruginous strata of the lower Silurian (Aeronian-Sheinwoodian) Clinton Group in east central New York State feature prominently in this debate, owing to many excellent exposures and a rich history of study (e. g. Eaton, 1824; Vanuxem, 1839, James Hall, 1852, Smyth, 1918). These ores, commonly referred to as the “Clinton Ironstones”, have never been mined on industrial scales, but they were processed extensively up to the mid 1900s as a source of red paint pigment (for a more comprehensive history see also Van Houten, 1991; Williams, 1998). Eight named ironstones are recognized within the Clinton Group; although these strata are of little economic importance today, they hold considerable stratigraphic, paleoecological, taphonomic, and sedimentological interest (e. g. Smyth, 1918; Gillette, 1947; Schoen, 1964; Brett et al., 1998; see Van Houten, 1991 for a detailed review). Three of the aforementioned eight ironstones will be featured in this field excursion through the classic type area of the Clinton Group, with considerations given to their history, stratigraphic significance, depositional conditions, and sedimentological features.

B5: IRONSTONES, CONDENSED BEDS, AND SEQUENCE STRATIGRAPHY OF THE CLINTON GROUP (LOWER SILURIAN) IN ITS TYPE AREA, CENTRAL NEW YORK

STOP 1. Roaring Brook - Type Section of the Westmoreland Iron Ore
Roaring Brook is the informal name given to a small, south flowing tributary of Oriskany Creek found in Lairdsville, a small Hamlet of Clinton, New York, in Oneida County. This locality was designated by Gillette (1947; p. 91-93) as the type section for the Westmoreland Hematite, though no detailed description of the outcrop was given. This section is located on private property and those wishing to view it must first obtain permission from the residents of 7012 NY Rte. 5 (Seneca Turnpike), in Lairdsville, NY. The most straightforward way of accessing the stream bed is by walking down the western slope of the valley cut by the stream where several paths provide relatively easy access to the section. A large (3-4 meter) waterfall, capped by the Westmoreland Iron Ore is a notable feature of this locality. A smaller falls, upstream and closer to the road, is capped by the Salmon Creek Bed.
This section has been featured previously as stop 13 of Brett and Goodman (1996). Five named rock units are exposed here; they are described and illustrated in ascending order herein (Figure 7).
Unit 1 - Sauquoit Formation
All strata exposed below the large waterfall at this locality are assigned to the Sauquoit Formation of the Middle Clinton Group (Sequence S-III of Brett et al, 1990). The Sauquoit Formation is reported to be approximately 30 meters thick in this area; the upper 6-7 meters of the unit is relatively well exposed along an approximately 0.25 kilometer stretch of creek bed extending downstream from the large waterfall.
Here, the Sauquoit Formation is dominantly greenish grey clay shale with thin interbeds of varying lithology that include planar to cross laminated, fine- to medium-grained calcareous quartzose sandstone and phosphatic, quartz pebble conglomerates. Many of these interbeds display numerous sedimentary structures, including sole marks, gutter casts, and asymmetrical, symmetrical, and interference ripple marks. Several thick, cross bedded sandstone interbeds occur near the top of the Sauquoit Formation at this locality, which contain abundant phosphatic shell fragments tentatively interpreted as lingulid remains. Below these upper sandstone beds is a locally present, rippled quartz phosphate pebble conglomerate.
Macrofossils are relatively sparse, though bedding planes may contain abundant bivalves and brachiopods. The brachiopods Strophochonetes (?) cornutus, Leptaena rhomboidalis, and Eocoelia sulcata are all relatively common, suggesting assignment to Boucot’s (1975) benthic assemblage 2. Bivalves are also quite common on some bedding planes, and very rare large trilobites have been found here as well. The presence of Ostracodes belonging to the Mastigobolbina typus Zone suggest a mid Telychian (C-5) age for these beds.
Unit 2 - Westmoreland Iron Ore
The large waterfall at Roaring Brook is capped by a 70-80 centimeter thick interval of bright red hematitic beds assigned to the Westmoreland Iron Ore. This horizon has been mined extensively here, and large portions of this unit are removed.
The bed is composed primarily of small, sand sized "oolitic" sediments composed of concentric laminae of hematite, chamosite, and berthierine surrounding a nucleus that is usually composed of a rounded quartz grain (Schoen, 1962). Several conglomeratic horizons are also found in the Westmoreland Iron Ore at this locality, composed primarily of quartz and phosphatic pebbles surrounded by a matrix of oolitic, hematitic grains. Brett and Goodman (1996) reported centimeter wide rectilinear cracks infilled with quartz and phosphate grains underlying the Westmoreland, which they interpreted as sedimentation within emergent mudcracks forming in the underlying Sauquoit. The upper surface of the unit displays large (∼10 cm high) symmetrical ripple marks.
The Westmoreland is sparsely fossiliferous here, though conodonts of the Pterospathodus celloni to Pterospathodus amorphognathoides Zones have been reported from the unit here (M. Kleffner, pers. comm. 1990 in Brett and Goodman, 1996). Brett and Goodman (1996) also report Eocoelia sulcata, Eospirifer radiatus, and Eoplectodonta transversalis, suggesting a late Telychian age for this unit. The thin, fossiliferous black shale bed reported in the Westmoreland Iron Ore at other sections by Gillette (1947) is not present here.
Unit 3 - Willowvale Shale
Sharply overlying the Westmoreland Iron Ore is the Willowvale Shale, which is approximately 6.1-7.6 meters thick in this area. At Roaring Brook, the unit is primarily gray to olive grey shaly mudstone with minor interbeds of light colored, sandy fossiliferous dolostones.
The Willowvale Shale yields a diverse marine fossil assemblage interpreted as the remnants of a relatively deepwater fauna (Eckert and Brett, 1989). The lower 0.3 to 0.75 meters of the Willowvale Shale contains several dolostone interbeds, which contain abundant specimens of a small discoidal rugose coral identified as Palaeocyclus rotuloides a fossil that appears in equivalent late Telychian strata throughout the world.
Unit 4 - Salmon Creek - Basal Dawes Bed
Upstream from the Willowvale bank exposures, the stream takes a sharp bend that leads up to a second, small falls just below the culvert under NY Route 5. This small falls is capped by a 40-50 centimeter thick, pinkish, blocky, sandy dolostone, which contains numerous small stringers of hematite; in the past this unit has been misidentified as Kirkland iron ore at some sections. This bed is interpreted as the basal bed of the Dawes, also referred to as the Salmon Creek Bed. The dominant fossils found in this unit are fragments of stalked echinoderms, primarily crinoids which are highly disarticulated and often impregnated with hematite.
Unit 5 - Dawes Sandstone
Above Unit 4 are a few meters of interbedded siltstones, sandstones and shales assigned to the Dawes Sandstone, which is the highest stratigraphic unit observed in Roaring Brook on the south side of NY Route 5. The unit is not fossiliferous and it is poorly exposed, being largely covered by soil and rip-rap sitting below the culvert under the road. Better exposures of this unit and some of the underlying beds can be viewed at the next stop.

STOP 2. Theime Gulf
The outcrops exposed at Theime Gulf are found in the banks of a small, northwest flowing tributary of Oriskany Creek. Five named stratigraphic units are featured at this stop, which partially overlap the section exposed in Roaring Brook at Stop 2 (See Figure 8). These outcrops are located on a private residence at 4486 Theime Gulf Road, in Clinton New York; visitors must obtain permission before entering. This section has been featured previously as Stop 14 of Brett and Goodman (1996).
Unit 1 - Willowvale Shale
The lowest exposed strata at Theime Gulf are assigned to the upper part of the Willowvale Shale. Here the unit is primarily a dark grey shaly mudstone with very few interbeds. Only the upper few meters of the Willowvale Formation are exposed here, and these can only be accessed with some excavation. A single interbed was observed, approximately 15 centimeters below the base of Unit 2. This bed was a dark grey, orange-brown weathering dolomitic carbonate containing abundant fossils, particularly the high spired gastropod Murchisonia, which is commonly infilled by a black mineral interpreted as phosphate.
Unit 2 - Salmon Creek - Basal Dawes
Overlying the Unit 1 is an 80-90 centimeter, reddish pink sandy carbonate grainstone horizon interpreted as the Salmon Creek, or Basal Dawes Bed which supports a small falls near the bottom of this section. This horizon appears to be much more ferruginous at this locality than at Roaring Brook (Stop 2). The unit is blocky and heavily cross stratified. Its upper and lower contacts are sharp, and small rip-up clasts are observed at several horizons. In contrast to the overlying beds, the Salmon Creek Bed is fairly fossiliferous. Stalked echinoderm columnals are the primary constituent of this assemblage, many of which are stained dark red with hematite.
Unit 3 - Dawes Sandstone
Overlying Unit 2 are approximately 3.2 meters of dark grey shales, siltstones and sandstones assigned to the Dawes. Fine grained shales and siltstones are the predominant lithology this interval, in contrast to the coarser beds observed at Dawes Quarry Creek. These units are generally finely laminated, though the numerous 5-25 centimeter sandstone interbeds are often massive, with ripples on their upper surfaces. Near the top of this unit is an approximately half meter interval of sandstone and shale showing extensive deformation and ball and pillow structures, which are interpreted as post depositional soft-sediment deformation.
Unit 4- Kirkland Iron Ore
Approximately two meters of massive, dark red dolomitic carbonates overlie Unit 3; these beds are assigned to the Kirkland Iron Ore. The unit is a highly fossiliferous crinoidal, pack- to grainstone with hematitic cement. Although crinoids are the dominant component of the Kirkland's fossil assemblage, bryozoans such as Acanthoclema and Eridotrypa are also important components. Several beds of the Kirkland display prominent cross stratification. The basal contact of the unit is sharp, but its upper boundary with the overlying unit is gradational.

STOP 3. Willowvale Creek at Woodhaven Wildlife Refuge
The Woodhaven Wildlife Refuge is a privately owned nature preserve occupying the site of a former picnic area in Chadwicks, New York. At this locality several tens of meters of section can be observed in the bed of Willowvale Creek, a small east-flowing stream which eventually passes under Oneida Street in Chadwicks. This section was described in detail by Gillette (1947; Section 34), and it represents perhaps the most complete, and best exposed outcrop of the Clinton Group in its Type Area. However, only thin, ironstone bearing excerpts of this entire section have been drafted here. Those interested in a more detailed and comprehensive descriptions of the outcrop are referred to Gillette (1947).
The creek was dammed in three places, forming small artificial ponds along the creek. At least two ironstone horizons are located some distance upstream; they may be accessed by a short walk through the scenic preserve. All outcrops described herein are on private land, visitors must first obtain permission from the administrators of the Woodhaven Wildlife Refuge.
Unit 1 – Sauquoit Formation
Unit 1, assigned to the Sauquoit Formation, is at least 35 meters thick at this locality, consisting primarily of blue grey to green gray shales and mudstones with many interbeds composed of calcareous sandstone, siltstone, and quartz-phosphate pebble conglomerates. The unit is abundantly fossiliferous; bivalves, ostracodes, and brachiopods predominate though some trilobites have been reported here as well. Intervals containing ball-and-pillow structures have been observed in shales at several intervals of the Sauquoit at this locality, which are interpreted as the post depositional soft sediment deformation of units, possibly due to seismic activity. The upper few meters of the Sauquoit Formation at this locality are difficult to access, though a relatively complete reconstruction can be compiled through a comparison of creek bed and gully wall outcrops.
Unit 2 – The Westmoreland Hematite
Numerous fragments of oolitic ironstone litter the creek bed, where their bright red color makes them easy to pick out. Many of these fragments are believed to originate from Unit 2, which is assigned to the Westmoreland Hematite. The only outcrop of this bed is located at N 43° 01' 47.39", W 75° 16' 49.25", this is within a very steep gully above the lake formed behind the lowest of the three Willowvale dams (Figure 9). Accessing the outcrop is quite difficult.
The unit is composed primarily of sand sized, iron coated grains which are deeply weathered in the outcrop. These are bright red in color, and unfossiliferous. A black shale lens within the hematite was observed here, similar to the ones described by Gillette (1947), but no fossils were observed in this horizon either.
Unit 3 – Willowvale Shale
Unit 3 constitutes the predominantly shaly unit between the ironstones represented by Units 2 and 4.This interval is interpreted as the Willowvale Shale which, like the Sauquoit Formation, consists of dark grey shales with occasional interbedded, fossiliferous calcareous sandstones. Unlike the Sauquoit, the shales of the Willowvale are dark to olive grey in color, and there are no conglomeratic horizons. The coral Palaeocyclus is abundant in the beds of the lower part of this horizon, though these can only be accessed with difficulty here. Other common fossils are brachiopods, bivalves, ostracodes, and graptolites.
Unit 4 - Dawes Sandstone
Unit 4 is a succession of relatively unfossiliferous blue grey shales with sandstone and siltstone interbeds. Although these beds were interpreted previously by Gillette, 1947, as the Willowvale Formation, we submit that this is a manifestation of the Dawes Sandstone. Although the Dawes is more shaly here than at Roaring Brook and Theime Gulf the zone of ball-and-pillow structures is similar to that of those and other successions of the Dawes.
Unit 5 - Kirkland Hematite
Unit 5 is a ferruginous limestone that forms the caprock of a small waterfall at approximately N 43° 01' 44.40", W 75°16' 57.31", just upstream from the lake formed by the middle Willowvale Dam. This bed is interpreted as the Kirkland hematite (or flux ore), a calcareous, fossiliferous hematitic ore overlying a zone of soft sediment deformation in the upper Dawes Formation (Figure 10). The unit contains abundant crinoids and stalked echinoderms, which are often stained dark red by hematite.
Unit 6 – Herkimer Sandstone
The Herkimer sandstone consists of orange brown sandstone horizons interbedded with very dark grey silty shales. Abundant ripple marks and cross beds indicate the unit was likely deposited in a relatively shallow environment close to normal wave base. The unit is fairly unfossiliferous, though large brachiopods and cephalopods have been found occasionally. Trace fossils, such as Palaeophycus and Rusophycus are relatively common.

STOP 4. (Optional) Forever Wild Nature Preserve
The Forever Wild Nature Preserve is a heavily forested area east of Washington Mills. The property is a privately owned and permission must be obtained before entering the property. Several excellent exposures of Lower Silurian strata may readily accessed from Brookside Terrace, a small, dead-end lane connected to Meadowbrook Drive in New Hartford New York. A well exposed section is exposed in the creek just south this road. These outcrops are described and illustrated herein (Figure 11), to our knowledge, for the first time in publication.
Unit 1 - Oneida Conglomerate
Strata exposed in the lower part of this creek section are predominantly unfossiliferous interbedded dark grey sandstones and quartz-phosphate pebble conglomerates assigned herein to the Oneida Conglomerate. Several of the sandstone beds have rippled upper surfaces. A meter thick zone of cross bedded conglomerate occurs near the top of the unit; these beds are composed primarily gravel sized, rounded clasts of phosphate and quartz set within a matrix of dark red, hematitic sandstone. This zone is overlain by a 25 centimeter interval of blue grey shale, which is in turn overlain by a pair of hematitic, conglomeratic units with lithologies similar to the beds found in the cross bedded zone. The upper of these two beds contains very large, symmetrical ripple marks that have amplitudes up to 15 centimeters. The Oneida-Sauquoit contact is tentatively placed at the top of this unit.
Unit 2 - Sauquoit Formation
Overlying unit 1 is a succession of blue to greenish grey shales with interbedded calcareous sandstones assigned herein to the Sauquoit Formation. These calcareous sandstone interbeds often have ripple marks on their upper surfaces, and many display hummocky cross stratification. Several of these beds are fossiliferous, containing abundant gastropods, bivalves, brachiopods, and ostracodes. Near the top of the section illustrated in Figure 11, there is a zone of irregularly bedded shales interpreted as the product of post depositional, soft-sediment deformation, possibly as a result of seismicity.