NYSGA 1965
GUIDEBOOK TO FIELD TRIPS
NEW YORK STATE GEOLOGICAL ASSOCIATION
37th Annual Meeting
Philip C. Hewitt and Leo M. Hall
Editors
Contributing Authors
Donald W. Fisher*
Yngvar W. Isachsen*
Philip C. Hewitt
Robert G. LaFleur
William E. McClennan
Harold Nilsson
Host
UNION COLLEGE
Schenectady, N. Y.
April I-May 2, 1965
* Published by permission of the Assistant Commissioner, New York State Museum and Science Service.

A: MOHAWK VALLEY STRATA AND STRUCTURE
Saratoga to Canajoharie
by Donald W. Fisher
State Paleontologist
New York State Museum & Science Service
"The crust of our earth is a great cemetery, where the rocks are tombstones, on which the buried dead have written their own epitaphs".
Agassiz

A: MOHAWK VALLEY STRATA AND STRUCTURE

Normanskill Graywacke
Outcrop of Middle Ordovician Normanskill Graywacke and Shale along east (northbound) lane. This is the westernmost extent of a large area of Normanskill, interpreted as a thrust outlier of the Taconic Allochthon or as a north-trending anticline protruding from beneath a cover of younger rocks.

Crossing Mohawk River
These dual tied-arch bridges won an award in 1958 for their design.

Former channel of the Mohawk River.
Crossing former channel of the Mohawk River. To the east, Round Lake occupies a portion of this now abandoned channel.

Snake Hill Shale
Long exposure in Middle Ordovician Snake Hill Shale, a dark gray silty facies of the Canajoharie Shale of the Mohawk Valley.

STOP 1. Lester Park
This is the type section for the Late Cambrian Hoyt Limestone, noted for its biostromal reefs of colonial algae called  Cryptozoon (see Fig. 9, Plate 1). The lowest reef has been planed by glacial erosion revealing the algal heads in horizontal section; a higher reef, in the recently enlarged road cut, exhibits a vertical section of  Cryptozoon. A still higher reef in the abandoned Hoyt Quarry displays a reef of algal mats rather than heads. Between the lowest and middle reefs is a coarse-grained dolomitic limestone with oolites and trilobite fragments; the genera  Prosaukia, Saratogia, Plethometopus, Plethopeltis, and  Dikellocephalus have been collected here, thereby establishing a Trempealeau age.
DEC Links 1 2 3

Petrified Gardens and Old Quarry
On left (east.) is entrance to Petrified Gardens, a privately owned exhibit of the Hoyt Limestone and its  Cryptozoon reefs. On right is old quarry in the Ritchie Limestone, either a local facies of the Hoyt or a slightly younger unit. Its rare fossils (the gastropod  Rhachopea) are not diagnostic. An east-trending normal fault separates this quarry from Lower Ordovician Gailor Dolomite on the downthrown, southern side.
DEC Links 1 2 3

STOP 2 ROCK CITY FALLS stratigraphic section.
In addition to studying several rock units here, there is a fine display of the Lower Ordovician-Middle Ordovician unconformity (disconformity) between the older Gailor Dolomite forming the face of the falls and the Amsterdam Limestone. The falls marks a fault-line scarp, upthrown on the west. The downthrown block exhibits Middle Ordovician Larrabee Limestone beneath the road bridge, some 70 feet lower than in the quarry on the upthrown block.

Glacial features
Morainal pond on north side of road; extensive cover of glacial sand and gravel in this region.

STOP 3
Basal Paleozoic cobble conglomerate consisting of quartz cobbles, derived from a Precambrian quartzite atop the hill to the north, in a siliceous, pyritic matrix. Midway in the exposure is some coarse textured, bedded, quartzose sandstone. This entire unit has been called Potsdam in the past because of its basal position and subjacency to the Theresa Formation, which crops out along the road to the west. Lithologically it is atypical for Potsdam; it seems to be a talus deposit, probably formed at the base of a sea cliff in Late Cambrian time., Precambrian biotite-gneiss may be uncovered by digging beneath this basal Paleozoic conglomerate.

Theresa Formation
Road cut in Theresa Formation, a unit with alternating quartzose dolomites and dolomitic sandstones with occasional golf-ball size quartzite pebbles.

Fault-line scarp
Climb fault-line scarp; this is the northern extension of the Hoffmans Fault, the most easterly of the Mohawk Valley normal or step faults.

Cliff of Little Falls Dolomite, upthrown side
Intersection with West Galway Road, proceed straight ahead. Cliff of Upper Cambrian Little Falls Dolomite on upthrown side of fault parallels road on the right.

Larrabee Limestone, downthrown block
Middle Ordovician Larrabee Limestone along road, on right, opposite old cemetery. This is the eastern downthrown block. Scarp veers southwestward.

STOP 4
There are two normal (gravity) faults here, both downthrown on the east with a small fault block (horse) caught between them (see Fig. 11, Plate 1). The eastern block shows steep east-dipping Larrabee Limestone with included round pebbles of a black, fine-grained, limestone (Amsterdam?) dragged against slightly westward dipping fine-grained, tan-gray, white weathering Lowville Limestone. The Lowville within this horse is overlain directly by the gray, coarse-grained Larrabee Limestone; the Amsterdam Limestone is missing from its accustomed position between the two in the Lower Mohawk Valley. Like all other horses observed by me, this one dips north or reverse from the regional dip. The west block exposes nearly horizontal Little Falls Dolomite.

Hoffmans fault
LEAVE horse, continue west on town road, crossing main branch of Hoffmans Fault.

View of Mohawk Valley to the SW
Atop hill, good view of Mohawk Valley to the southwest, looking down dip.

Underlain by Little Falls Dolomite
This region underlain by Little Falls Dolomite.

Little Falls Dolomite
Long road cut in Little Falls Dolomite (both sides of road). Quartz crystals and chert are absent here although we are less than 50 feet below the Tribes Hill Fm.

Pre-glacial valley
Lower area to west is the course of a pre-glacial valley, tributary to the Mohawk.

Hoffman's Fault
Straight ahead at intersection with West Glenville Road. Outcropping of thick-bedded, coarse-grained, light gray Larrabee Limestone (with "Shoreham" fossil  Cryptolithus) on lumpy-bedded, fine-grained, dark gray to black Amsterdam Limestone on southwest corner. This is the fault-line scarp of the Hoffmans Fault.

STOP 5
WOLF HOLLOW and LUNCH Park on left,horse on right. The road and stream follow the fault trace of the Hoffmans Fault which, here, has a vertical displacement (throw) of at least 1000 feet and very probably as much as 1600 feet (see Figure 8). The downthrown (east) block exposes Middle Ordovician Schenectady Graywacke and Shale in the southern part of the Hollow and Canajoharie black shale in the northern part. The upthrown (west) block shows the Lower Ordovician Gailor Dolomite forming the impressive cliff. A small horse on the west side of the road of "Shoreham" Limestone and Canajoharie Shale dips north. Wolf Hollow well exemplifies the role exerted by faults in controlling drainage.

Fault exposure
Sharp left curve. Schenectady Graywacke and Shale dragged at a 40° angle, diminishing to less than 5° at eastern limit of exposure, some 500' distant.

Cliff
Long high road cut begins where Toureuna Road joins NY 5; lower 40' is Little Falls Dolostone and the remainder of the cliff is Gailor Dolostone. A small hill atop the cliff exhibits Lowville, Amsterdam, Larrabee, and "Shoreham" Limestones and Canajoharie Shale in their normal stratigraphic positions. Thus, the stratigraphic succession can be demonstrated conclusively in this single section.

Road cut on NY 5 at railroad overpass. The two middle members of the Tribes Hill Formation are exposed here;the massive Wolf Hollow dolomitic calcilutite (fine-grained limestone) is in contact with the thin bedded Palatine Bridge dolomitic shale and quartzose calcisiltite (medium grained limestone) and calcilutite. Note the white and buff fretwork weathering of the Wolf Hollow member with the buff dolomite in relief. The Palatine Bridge member is lighter colored and more quartzose and pyritic. A single dolomite bed, 2 1/2 feet thick, in the lower part of the Wolf Hollow member can be traced throughout the Valley; it is a bluish-gray, medium-textured dolostone with pockets (vugs) of dolomite crystals. Fossils are scarce in both members. The Wolf Hollow member has a molluscan fauna of large, loosely coiled gastropods and straight or gently curved ellesmeroceroid and clarkoceroid cephalopods. In contrast, the Palatine Bridge member has an arthropod (trilobite) and brachiopod fauna. Both faunas indicate an Early Canadian (=Tremadoc) age.

Fort Johnson
Baronial home of Sir William Johnson built in 1749 on northwest corner.

Tribes Hill Fault
Cross Tribes Hill Fault, upthrown on west.

Roadcut with weathered rock
On north side of NY 5 is a cut in the same portion of the section viewed at the previous stop. Note the change in appearance owing to longer weathering (exposed initially in 1958). When first revealed, there was a two-foot iron oxide zone at the top of the Palatine Bridge member; this corresponds to the two-foot dolomitic shale zone at the previous stop.

Parking area
Parking area, splendid view of Mohawk Valley with Schoharie Valley in distance.

On north side of NY 5, Middle Ordovician Canajoharie Shale, here more of a calcareous argillite which is typical of the lowest 200' of the formation, has graptolites (See Figure 13, Plate 1) in the upper few feet of the exposure. These extinct animals, excellent guide fossils for subdividing the Ordovician and Silurian Periods, are thought to have been floaters (plankton) and, thus, achieved wider distribution in a relatively short period of time as compared to bottom dwellers.

STONE RIDGE This is a critical section in deciphering structure and Ordovician stratigraphy in the Valley.
The three upper members of the Tribes Hill Formation are exposed (upper Palatine Bridge and Wolf Hollow in Van Wie Creek to the west of Borden Road and Fonda member in road ditch and road cut). The Chuctanunda Creek Dolostone is missing due to erosion. This is a superb example of a disconformity (See Figure 7). The older Tribes Hill Formation has been subjected to subaerial erosion and the crevices at its summit are filled, in places, with whiteweathering Lowville Limestone with vertical worm borings. Lumpy bedded limestone (Amsterdam or Larrabee ?) occurs above; the fossils are not diagnostic in distinguishing which Middle Ordovician unit crops out in this cut. Further up Van Wie Creek, undoubted Larrabee and "Shoreham" Limestones are overlain by Canajoharie Shale. In the road ditch a coarse grained limestone (calcarenite) with glauconite yields abundant fossils. Most of these are stained with iron oxide and are water-worn. Gastropods are abundant but the unusual pelecypod-like arthropod,  Ribeiria, (See Figure 14, Plate 1) exceeds all others in numbers. Trilobites, ellesmeroceroid cephalopods, and brachiopods round out the major faunal elements. Rare calyx plates of cystids and conodonts complete the known fauna.

Fonda wash plain across river
Note flat topped Fonda wash plain across river. This is an Ice Age delta consisting of water-laid gravels and sands which extends north for 4 1/2 miles and west for 3.5 miles from Fonda to the Noses Fault.

NOSES FAULT and ANTICLINE ? NONCONFORMITY or FAULT CONTACT ?
Park next to barn at intersection of Anderson and Currytown Roads, walk across bridge over Yatesville Creek through private property to rock exposures along railroad and old Erie Canal.
Precambrian garnet-biotite-gneiss brought to surface along old canal and railroad in upthrown (western) block of Noses Fault. These exposures of the basement could be due to relief of the Precambrian surface or to an anticline being upwarped slightly west ? of the Noses Fault. The basal Paleozoic rock here is the Late Cambrian Little Falls Dolostone. This Precambrian outcrop (one of five within this inlier) is capped by a one foot shaly zone rich in quartz and pyrite; some traces of gold and silver were reported by Darton (1895). Is the shaly zone fault gouge or is it residual soil atop the Precambrian? One must look to the basal Little Falls breccia to determine whether it is tectonic or sedimentary. You be the Judge! Much of the Little Falls Dolostone here is heavily chertified; quartz crystals may be found after careful search. Elsewhere within the inlier, the basal Little Falls is not brecciated but is a dolostone rich in rounded quartz grains. At the Precambrian exposure north of the river along NY 5, a six foot wide mafic dike (unmetamorphosed) cuts the older garnet-biotite-gneiss. The basal Little Falls is concealed but exposures 20 feet above the Precambrian are not penetrated by the dike. Presumably, the dike was injected during a late Precambrian (Keewanawan) orogenic episode. Very scarce lingulid brachiopods are the sole fossils discovered in place in the lower Little Falls at the Noses Inlier. A loose  Elvinia free cheek was found by me along the raIlroad in 1949. Within the Late Cambrian this would signify an early Franconian age.

Noses Fault and Yatesville Creek
Proceed south (uphill) paralleling Noses Fault. Note that Yatesville Creek's course is largely controlled by the fault.

Dragged Shale
Dragged Canajoharie Shale along road on right. Dips up to 75° E.

Ledge of Wolf Hollow Limestone
Ledge of Wolf Hollow Limestone crosses to the east of the road. Canajoharie Shale in road ditch near house. Upper Tribes Hill (Fonda), Chuctanunda Creek Dolostone and Lowville, Amsterdam, Larrabee, and "Shoreham" Limestones are missing here owing to either non-deposition or, more probably, erosion. The Canajoharie Shale, too, is but 350' thick. This area atop the Noses is considered to be the crest of the Adirondack Axis and was an effective barrier to sedimentation and faunal interchange during the Wilderness and early Barneveld Stages of the Mohawkian Series.

Look back at scarp
Looking backward, note Noses scarp extending north toward Precambrian Adirondack Mountains. Land to the east (downthrown block) underlain by Middle Ordovician Schenectady Formation. Throw of the Noses Fault here about 500'.

Largest Horst
For the next two miles we are traveling across the top of the largest horst in the Mohawk Valley.

View to Southwest
Note hills to the southwest near Cherry Valley composed of Lower and Middle Devonian strata. At Sharon Springs, 8 miles south of Canajoharie, Late Silurian Brayman Shales are in contact with Medial Ordovician Schenectady shales. A few miles west of Cherry Valley, the Medial Silurian Clinton Group intervenes between the Late Ordovician Frankfort Shale and the Late Silurian Vernon Shale. The Paleozoic section, thus, thickens markedly as one proceeds west from the Adirondack Axis. The section also thickens markedly east of the Axis but the thickening occurs within the Medial Ordovician.

Dropping off horst
Dropping off western side of the Noses horst; good view looking up the Mohawk Valley toward Fort Plain and St. Johnsville.

River alluvium
Cross Flat Creek and drive on river alluvium to Canajoharie.

Inactive quarry at eastern limit of Canajoharie on south side of NY 5-S exposes the Cambrian-Ordovician contact, i.e. Little Falls Dolostone-Tribes Hill Formation. The uppermost Little Falls Dolostone is stained red with interstitial hematite and has vugs of quartz and anthraxolite. Anthraxolite is a black mineral with 92-98% carbon with much the same composition as anthracite coal. The physical properties, however, are quite different. For example, anthraxolite does not ignite. Note that anthraxolite occupies the lower half of the vugs; the upper half is usually filled with quartz but sometimes dolomite crystals complete the cavity. Anthraxolite is believed to be a hydrocarbon residue of petroleum and to have been derived from algal reefs in the Late Cambrian seas.
The overlying Fort Johnson member of the Tribes Hill Formation is a calcitic dolostone to dolomitic calcilutite. Its scarce fossils (Ophileta, Finkelnburgia, Asaphellus) denote an early Canadian age. Because the uppermost Little Falls Dolostone here has not yielded any fossils (except the non-diagnostic  Cryptozoon we cannot be certain whether the Little Falls - Tribes Hill contact here is a paraconformity (surface of erosion but with no relief) indicating a gap ip the record or whether the subtle change from relatively pure dolomite below to dolomitic limestone above indicates continuous sedimentation from the Cambrian into the Ordovician Period. The physical clues (zone of hematite, vuggy dolomite with contained minerals) lean toward the paraconformity view (see Figure 7). The splendid long stratigraphic sections along Flat and Canajoharie Creeks cannot be examined by large groups. They are, however, critical in reconstructing the geologic history of the Valley and are accordingly included in Figure 3.

Water Gap
Valley narrows to water gap at the "Noses"; valley walls are entirely Little Falls Dolostone.

Dike
Across river, road cut in Precambrian on NY 5 showing six-foot dike cutting garnet-biotite-gneiss.

Anticlinal Effect
Precambrian gneiss and Little Falls Dolostone on right along old Erie Canal and West Shore branch of N.Y. Central Railroad displaying anticlinal effect.

Two Kames
Across river, two kames (chocolate-drop-shaped hills) of gravel and sand in shadow of Noses escarpment. Fonda flat-topped wash plain extends from here for 3.5 miles eastward to Fonda.

Gravel over boulder till
Water-laid gravel and sand overlying boulder till blankets much of the inner valley from here eastward.

Roadcut
Road cut along eastbound lane exposing uppermost Tribes Hill Formation, Amsterdam, Larrabee, and "Shoreham" Limestones.

Auriesville Shrine
Auriesville Shrine atop hill to the south.

Schoharie Creek
Schoharie Creek, east side of Schoharie Valley here is boulder till.

Gailor Dolostone
Across river, large cut in Gailor Dolostone, the dolomitic facies of the Tribes Hill Formation.

Hoffman's Fault
Crossing Hoffmans Fault.

Lower Ordovician Dolostone
Road cuts along eastbound lane in Lower Ordovician Dolostone.

Schenectady Graywackes and Shales
Hills forming Valley walls composed of Schenectady Graywackes and Shales.

Lake Albany Plain
Mohawk Valley broadens into Lake Albany Plain. Note gravels along north river bank. These thick gravels and sands are excellent reservoirs for ground water; the entire city of Schenectady and neighboring suburbs obtain their public water supplies from these almost inexhaustible water-bearing glacial deposits.

Climb out of Mohawk Valley
Climb over south valley wall out of Mohawk Valley proper.

Helderberg Escarpment
Prominent topographic feature straight ahead is the Helderberg Escarpment (not produced by faulting). Note terraces of Lower and Middle Devonian Limestones.

West shore of Lake Albany
Approximate west shore of glacial Lake Albany. Sand plains with profuse growth of pine trees extend from here to Albany. Area of sand dunes atop lacustrine varved clays, the dunes produced by wind whipping the relatively thin veneer of lacustrine sands into north-south trending hills.

Sand Dune
Sand dune.

Boulder till

B: GEOLOGIC EXCURSION FROM ALBANY TO THE GLEN VIA LAKE GEORGE
by Yngvar W. Isachsen

B: GEOLOGIC EXCURSION FROM ALBANY TO THE GLEN VIA LAKE GEORGE

Glacial Lake Albany terrace
The road cuts through an arrested sand dune developed on a former sand terrace of glacial lake Albany.
The excursion route between Albany and the Lake George region passes over the floor of this glacial lake. It is marked by lacustrine sand terraces which have, in part, been reworked by wind to form an undulating dune topography. The landscape has been further modified by post-glacial drainage. Beneath the sand veneer, which is generally less than 50 feet thick, is a rock terrace at about 300 feet elevation. This Tertiary erosion surface forms a broad platform extending between the block-faulted scarp of the Adirondack Highlands on the northwest, and the Taconic Mountains on the east and the Appalachian Uplands to the south.

Descend to Mohawk
Road descends toward the Mohawk River cutting through the blanket of lacustrine sands and into the Middle Ordovician Normanskill Formation which is exposed on the right. Lithologies represented are graywacke with mud pellets ("flysch and chips") and overlying shale. The large area of Normanskill of which this is a part has been interpreted alternatively as a thrust outlier of the Taconic klippe and as the core of a north-trending anticline.

Bridges
The attractive pair of tied arch bridges spanning the Mohawk River ahead received honorable mention for design in 1958 by the American Institute of Steel Construction.

Mohawk and Gorges
Cross the Mohawk River which here occupies a post-glacial gorge cut into the Normanskill Formation.
Immediately to the west is a deeply buried pre-glacial gorge referred to as the Colonie channel (Fig. 6). Since this paleostream channel has the flattest gradient of the tributaries as presently known, it may have been the major river draining the southeastern Adirondack region in Tertiary times. In contrast, the buried Tertiary Hudson channel probably drained the Hoosic and Batten Kill water sheds, as does the present Hudson River, but did not extend much farther north (Simpson, 1949). Beneath the present Hudson River at the foot of Madison Avenue in Albany, the buried Tertiary Hudson channel is almost 100 feet below sea level.
Immediately west of our present location, the floor of this filled channel is about 200 feet below the present Mohawk River which meanders across it at right angles. At the north end of Saratoga Lake it is about 45 feet above sea level, and west of the City of Albany about 80 feet below sea level.
The Northway roughly follows the course of this channel for the next 20 miles or more to a point at the north end of Saratoga Lake (Fig. 6). Beyond this, its extension is largely hypothetical, although supported where drawn across the present Hudson River near Glens Falls by an anomalous lack of outcrop in that short stretch. From Albany north for a distance of about 10 miles where the configuration is best known, it is a relatively steep walled channel, perhaps owing to glacial 'scour.'
The main tributary to the Colonie channel, the ancestral Mohawk Channel shown on figure 6., has been traced as far west as the Hoffman Fault where a 100 foot high waterfall may have existed in pre-glacial times (Simpson, 1949). There are about 200 feet of channel-fill in the stretch between Schenectady and Hoffmans, and the present Mohawk River meanders over its surface.'
Within the next mile the road climbs back up on the Pleistocene cover. Immediately to the east, a bedrock ridge protrudes a hundred feet above the level of the Tertiary terrace. Such relatively rare projections were islands in glacial lake Albany, which had a shoreline at about the present 300 feet contour.

Ballston Creek
Northway crosses one of the glacial meltwater channels which is now occupied by Ballston Creek. Looking down the valley to the southeast the Round Lake depression may be seen. This and Saratoga Lake to the north represent unfilled depressions, perhaps kettle lakes, on the glacial debris occupying the pre-glacial Colonie channel (Woodworth, 1905; Cook, 1930 p. 197).

Drummond Creek
Road descends into the valley of Drummond Creek, and for one-half mile cuts into highly fissile black shale of the Snake Hill Formation.

McGregor Fault
The escarpment which has been intermittently visible to the west extends from Saratoga Springs northward for a distance of 25 miles. It is a fault line scarp produced by differential erosion along the McGregor fault which marks the boundary between the Precambrian (here composed mainly of east-west trending metasedimentary rocks) and the Paleozoics. On the basis of measured Paleozoic sections in the Mohawk and south Champlain valleys, it is estimated that the vertical displacement along the McGregor is at least 2200 feet.
It is only possible at present to date the normal faulting of the eastern and southern Adirondacks and the adjoining Mohawk Valley region as post-Frankfort (i.e. post Late Ordovician) inasmuch as these are the youngest rocks known to be involved. All of the faults in the Mohawk Valley region either hinge out before reaching the Silurian at the base of the Helderberg escarpment, or pass beneath it without being recognized. Field relationships do not permit an absolute resolution of this question, but the fault movement is inferred to have occurred during the Taconic disturbance (Kay, 1942, p. 1627).

Precambrian outcrop
Outcrop of Precambrian; the rock here a quartzo-feldspathic gneiss, similar to that exposed at STOP 1.

Large scale recumbent folding and related structures in biotitic paragneiss.

View of Lake George
Note views of Lake George which lies in a graben between two blocks of Precambrian gneiss.

You are standing on Paleozoic rocks at the floor of the Lake George complex graben, completely surrounded by Precambrian rocks. The steeply rising valley walls are fault-line scarps which give the region a spectacular relief such as is generally found only well within the Adirondack perimeter; the local relief here reaches 2000 feet. Combining this value with the 500 foot estimated thickness of the Paleozoics here gives a minimum vertical displacement of at least 2500 feet.
The crystal clear waters for which this lake is noted, result from the fact that only short mountain brooks drain into the lake, and hence the very fine clay fraction common to most drainage systems is virtually absent. Most of the lake is not deeper than 50 feet, although measured depths of up to 190 feet are shown on the hydrographic map published by the Lake George Power Squadron. The many islands in Lake George number 184, and of those 154 are State-owned. Most are composed of bedrock but several are gravel drumlins according to Newland and Vaughan (1942).
Lake George now drains northward into Lake Champlain, with a decent of more than 200 feet (from 319 ft. to 95 ft.). In Tertiary time, however, both lake basins were river valleys separated by a drainage divide. The Lake Champlain valley drained into the St. Lawrence as it does today, but the Lake George basin drained southward through the relatively wide graben valley located just east of French Mountain (Fig. 7). This valley is now clogged with glacial debris including a well-shaped drumlin 1 and 1/2 miles long (Fig. 7). The inferred Tertiary drainage course is shown in Figure 6.
At the close of the last ice advance, a glacial lake occupied the basin as indicated by the presence of sand terraces representing several transitory levels in the lowering of the lake to its present elevation. The highest of the terraces has an elevation of 600 feet, and is well represented 1 and 1/2 miles to the southeast, just uphill from the Northway exit on Route 9L (see mileage 56.3).
The Paleozoics here are exposed in the railroad bed of an abandoned spur of the Delaware and Hudson Railroad, which carried vacationers from down-state to Lake George via Fort Edward and Glens Falls, until 1957. The exposed dolomite strata are either Little Falls or Beekmantown equivalents; fossils have not been found. A fault breccia in the cut contains fragments of lithographic limestone which are probably down-dragged Beekmantown limestone.
A brief summary of Colonial history of the Lake George region is given in the appendix.

Spheroidally weathered gabbro
Spheroidally weathered metagabbro is exposed in road cuts on the right.

Be alert for falling rock!
This outcrop is interpreted as an untransported soil (saprolith) formed by weathering during the Tertiary from biotitic quartz-feldspar gneiss. Note the degree which Precambrian structures, textures, and minerals are preserved. Above the Tertiary saprolith, the Pleistocene is represented by two fluvioglacial boulder gravel units. The lower gravel is weathered and hence of probable preclassical Wisconsin age; the upper gravel is unweathered and of presumed classical Wisconsin age.
When the exposure was first created in 1936, a 2 to 3 foot thick layer of varved clay was visible between the boulder gravels. This clay is thought to have-accumulated in a local body of water along the ice edge rather than as part of the main glacial lake that occupied the Lake George valley, inasmuch as the clay here is some 180 feet above the highest glacial sand terrace in Lake George Basin (Newland & Vaughan, 1942).
Tertiary saproliths such as this rarely survive Pleistocene glaciation, and are even more rarely exposed, owing to rapid mechanical disintegration and concomitant plant overgrowth. This steep outcrop apparently survives only due to constant removal of material for human use from its base. Similar saproliths have, however, been discovered in a number of localities in the Adirondacks, and in the Hudson Highlands as well, by geologists of the State Department of Public Works in connection with highway construction; they are generally short lived exposures. The structural and topographic conditions that control the preservation of these soils have not been investigated.

Spheroidally weathered gabbro
Where hill starts to level off, note the spheroidally weathered metagabbro cropping out on the right. A fresh outcrop of this lithology will be seen at STOP 5, just north of Warrensburg.

New road cuts being made for the Northway here expose pink, gray and green varieties of granitic gneiss. The typical pink granitic gneisses of the Adirondacks are composed chiefly of microcline or microperthite and quartz along with subordinate amounts of oligoclase and one or more of the dark minerals, hornblende, biotite, pyroxene. In most areas, these gneisses are equigranular, but in parts of the southeastern and northwestern Adirondacks they are inequigranular, containing pink microcline crystals (probably porphyroblasts) which measure up to an inch or more in length. This variety is generally considered to have formed by metasomatism of a biotite-quartz-plagioclase paragneiss into which it grades laterally. A subordinate lithology in this suite is leucogranitic (alaskitic) gneiss which is most prominent in the Northwest Lowlands, although it appears in the southern and southeastern Adirondacks. In the eastern Adirondacks, several large magnetite ore bodies occur in this gneiss. The granitic gneisses occur as sheets or lenses in a variety of other rock types.

Schroon River
The highway follows the flood plain of the meandering Schroon River. Sand terraces at an elevation of about 760 feet may be seen 80 feet above the valley floor. These are representative of Glacial Lake Warrensburg. (Miller, 1923).

Both contacts of this thick sill are clearly delimited, and the lower one is actually exposed.
Aside from obvious metasedimentaries, metagabbro is the only metamorphic rock in the Adirondacks whose origin has never been questioned for reasons given earlier.
Although all the minerals of this sill are the product of metamorphic recrystallization, the textures are relict igneous except at the very margin where the rock has been converted to a biotite schist.
The textures are best shown on weathered surfaces. Throughout most of its width, the sill displays a subophitic fabric, but within a few feet of the contact, the rock has a finer-grained chill border with a diabasic texture. The laths of plagioclase that define these relict textures are not single crystals of plagioclase, as originally, but granoblastic aggregates of andesine-labradorite which presumably represents an equilibrium composition for this metamorphic grade and for this bulk chemical composition. In some Adirondack metagabbros, cores of unrecrystallized igneous minerals have survived metamorphism; most notable are "dusty" plagioclase, augite, hypersthene, and olivine.
Primary constituents of the Adirondack metagabbros are plagioclase (labradorite to bytownite), augite, hypersthene, olivine, ilmenite, and magnetite. Re-equilibration of this mineral assemblage under conditions of granulite facies metamorphism has resulted primarily in reaction between plagioclase and the mafic minerals to produce less calcic plagioclase plus garnet and/or augite. Where water has entered the system, hornblende is a common metamorphic mineral. In many metagabbros the border zone has been converted to amphibolite lacking all trace of the parent igneous texture. Aside from the local addition of small amounts of water, however, the metamorphic reconstitution of gabbroic rocks in the Adirondacks has been an essentially isochemical process. In this exposure, the relatively high biotite content of the metagabbro along its lower contact indicates limited influx of K2O as well as H20 .
This roadcut clearly shows the metagabbro to be a sill. Commonly, however, the poor outcropping characteristics of the thinner metagabbros make it difficult or impossible to determine shape of the intrusives. This may account in part for the fact that the bodies are commonly shown on the older reconnaissance quadrangle maps as circular masses (Fig. 2).

Fault breccia in chloritic hornblende-biotite granitic gneiss is evidence of an episode of brittle deformation. Rotated angular and tectonically-rounded fragments of the gneiss are cemented by a chlorite paste, and within the gneiss biotite is largely altered to chlorite. This retrograde metamorphism and the local presence of drusy cavities are among the features of Phanerozoic faults that transect the Precambrian.
Dating the normal faulting that is so prevalent in the southern and eastern Adirondacks and in the adjacent Mohawk Valley (Fig. 6) is a major regional problem. The wise adage of mining geologists, "Once a fault always a fault," doubtless applies here and further complicates the problem. Inasmuch as the trends, steep dips, and other structural characteristics of those faults which are wholly confined to Precambrian crystallines do not differ from those which also involve the peripheral Paleozoics, it might be assumed that all are of the same age, namely, post-Frankfort, as mentioned under Mileage 31.5. Some faults, however, are marked by healed breccias whose mineral assemblages are in equilibrium with the regional metamorphic grade of the Precambrian Grenville orogeny. Thus, some Phanerozoic normal faulting apparently represents reactivation along Precambrian zones of weakness.
It may be of interest to note in passing that such normal faulting accounts for the rectangular drainage pattern in the Elizabethtown quadrangle to the north. Prior to detailed geologic mapping by Matt Walton, the Elizabethtown quadrangle had been cited for many years as a classic area of rectangular drainage induced by rectangular jointing.

Outcrops of paragneiss
On the left are outcrops of paragneiss, and immediately to the north are exposures of intricately contorted and refolded calcite marble and interlayered calcsilicate rock.

Marble
Road cuts through isoclinally folded beds of calcite marble containing laminae of calc-silicate minerals.

At junction of Route 28 and Potter Brook Road. Charnockitic gneiss. This rock is part of a "charnockitic suite" of metamorphic rocks which has widespread occurrence in the Adirondacks (Fig. 2). The suite includes the true charnockites (hypersthene-bearing gneisses of granitic composition) and varieties departing from granitic composition by: 1) having a lower quartz content than the required 10% (or 20%, depending upon rock classification used), and 2) a range in the ratio of plagioclase to K-feldspar of from less than 1 to more than 1. The gneisses are characteristically gray to dark green in fresh exposures, and weather to a maple-sugar brown; pink facies occur also, however. Microperthite is the predominant mineral; mafic minerals may include hypersthene, augite, hornblende, biotite, and garnet. Owing to the variation in percentages of the "essential" minerals, (commonly within a single mapping unit) and the attempt to fit these lithologies into igneous-rock pigeonholes, they have been mapped under at least 12 different names during the past 50 years. They have been most commonly designated "quartz syenite" and "syenite". However, such terms carry a misleading connotation inasmuch as the rocks are at present largely, if not wholly, metamorphic, whatever their ultimate origins.
In much of the Adirondacks, rocks of this suite occur as unbanded, relatively monolithic layers many hundreds of feet thick. In the southern Adirondacks however, banded charnockitic gneiss with intimately interlayered sedimentary rocks occurs in a number of areas. The monolithic layers are most commonly exposed as the cores of domes and antiforms, as is expectable from their relatively high resistance to erosion.
The Hudson River, which flows by a few hundred feet to the west, is cut into metasediments.

Quarry on right side of the road in banded, pink and gray paragneisses with scattered biotite schist layers. Breccias occur at northern end of outcrop, but more prominent there is a diabase sill with fine-grained chill borders. This is one of many such undeformed diabase intrusives in the Adirondacks. They generally occur as this, steeply-dipping dikes. Inasmuch as they are undeformed they must postdate the Grenville Orogeny. They have been generally interpreted as Late Precambrian.

Roadcut in marble across from junction with road to Friends Lake.
The calcite marble and calc-silicate beds here are typically highly deformed, having been isoclinally folded - and probably refolded as well. The relatively competent calc-silicate layers have been stretched, attenuated, and dismembered well beyond the boudinage stage so that they occur as disconnected lenses, hooks, and clots. Such floating fragments have sometimes been picturesquely tagged "tectonic fish", and "dead snakes". Minerals which can be readily found and identified include graphite, diopside, brown tourmaline (dravite), pyrite, sphene. Undeformed mafic dikes with fine grained chill borders may be seen cutting the marble.
Continue on Route 28 across Hudson River, which here cuts into metasedimentaries.

Cross a second bridge, over small, tributary to the Hudson River, and immediately park on the left at entrance to closed road. Descend to stream, where may be found glacial boulders of most of the resistant Adirondack lithologies. The only major rock type not yet seen on this excursion - anorthosite - is well represented. Both the relatively pure Marcy-type anorthosite, and the more mafic Whiteface type maybe found. Proceeding upstream a short distance, a wide variety of metasedimentary lithologies may be seen cropping out in the stream bed. These include: paragneisses, quartzites of varying purity, amphibolite, marble and calcsilicate rocks.

C: GLACIAL LAKE SEQUENCES IN THE EASTERN MOHAWK-NORTHERN HUDSON REGION
by Robert G. LaFleur
Department of Geology
Rensselaer Polytechnic Institute
18 Stops
No road log

Long, narrow drumlins with east-west trend, 2 miles west of Mariaville Lake.

Flaggy boulders of Schenectady Formation predominate drift north of Duanesburg; well exposed along Duanesburg Churches Rd. Excellent view of drumlin terrane north from Highland Park Rd.

Overlook of Duanesburg channel (of Delanson River) at Duane, Rt. 7 one mile south of Duanesburg.

Drumlins north of Rt. 20, 1 1/2 miles east of Duanesburg. Roadcut exposes till. Good view north across Normans Kill valley.

Overlook of lower Mohawk Valley from hill one mile northwest of Rotterdam; 350' terrace remnant of Mohawk delta; river gravels; islands in the Mohawk River at Scotia.

Outlet channel of Early Lake Amsterdam now occupied by NYS Thruway; 1/2 miles west of exposure no .·5.

Delta in Late Lake Amsterdam at Hoffmans; Wolf Hollow gorge of Chaughtanoonda Creek has formed along the Hoffmans Fault, accentuating a striking topographic lineament traceable for 3 miles to the north.

Glenville kames along the West Glenville Rd.; suggesting the location of the ice margin which defended Early Lake Amsterdam.

View from Potter Rd., one mile north of Glenville, south to rock benches of the Glenville Hills.

View from Ostrander Rd., one mile east of Guilderland Ctr., southwest to Helderberg escarpments.

Along Grant Hill Rd., one mile southeast of exposure no. 10; dissection of the south (lee) side of a drumlin by the Normans Kill exposes 100 feet of bouldery till.

Guilderland kame terrace along southwest shore of the Watervliet Reservoir. Several gravel pits expose southwest-dipping gravels and sands; also isolated pockets of rhythmic clays. A solitary kame is located at the intersection of Routes 158 and 146. The Lake Albany 330' beach has modified the northeast (ice contact) side of the kame terrace.

Rensselaer (Lake Albany) kame delta, east of city limits of Rensselaer. Turbidite sands in delta bottomset beds; graded bedding, sole markings.

Lake Albany beach ridge with gravel pit excavation; one mile north of Defreestville on Bloomingrove Rd.

Teller Hill promontory, one-half mile west of Sherwood Park. Panorama of Hudson Valley, the Hampton Park kame delta, and the Hudson flood plain.

Eskers of the Albia-Burden Lake complex, exposed in several large gravel pits on Route 66 east of Wynantskill.

Panorama from East Line Rd., 3 mlles north of Jonesville. Ballston outlet channel at East Line; Round Lake depression and channel, Malta sand plain. Round Lake channel also shown where it is crossed by the Northway one mile east of exposure no. 17.

Coveville outlet and plunge pool three miles south of Schuylerville on west side of Hudson River.

D: GEOLOGIC PHENOMENA IN THE SCHENECTADY AREA
by
P.C. Hewitt
Wm. E. McClennan Jr.
Harold Nilsson
Three Stops
No road log

STOP 1 The Clifton Park Anticline
Location
The outcrop is located at the top of a hill in the town of Clifton Park on N.Y. Rt. 146, 1.7 miles east of the intersection of Rts. 9 and 146. If approached from the east the outcrop lies 0.5 miles west of the intersection of Rts. 146 and 236.
Description
The Clifton Park anticline is an excellent outcrop for teaching purposes. At the one locality many structural and sedimentological features may be observed. It also is a prime example of the thrust faulting in the eastern part of the lower Mohawk Valley. There are only a few faults of this type in the area and they probably represent only small scale thrusting. Though associated with Taconic thrusting they are not part of the Taconic region itself but are west of the westernmost zone of that much discussed area.
The strata exposed at Clifton Park are assigned to the Normanskill formation and represent primarily the Austin Glen Graywacke member. Some black shales are interbedded with the siltstones and graywackes. The mud pebble conglomerate so common in the Normanskill may also be observed at this outcrop. No fossils have been reported from this exposure but the lithology is typical of this Middle Ordovician unit and fossils found in the near vicinity assure this age assignment. The outcrop extends for about 600 feet on either side of the road. It is apparent from a rapid glance that the strata on the north side of the road do not match those on the south side. To gain the most from this exposure it is best to start your traverse at the west end on either side of the road and to walk toward the east and return in the opposite direction on the other side of the road. A series of thrust faults may be seen on either side of the road.
At the west end of the exposure on the south side of the road is a small thrust which may be observed to blend into a bedding plane fault to the east. Virtually all of the faults show mineralization along the fault plane. The mineralization usually consists of well slickensided calcite. No individual fault can be traced any great distance but there is no difficulty in detecting the faults nor in following them over a distance of several yards or more. The entire section of strata on the south side appear to be less contorted than on the north. This is more apparent than real, however, for the whole area is part of an anticline plunging to the south.
Structural features on the north side of the road are quite different. Starting at the east end one may see beds dipping about 30° to the southeast followed by a small symmetrical anticline. About 25 ft. further west is a small faulted anticline. The fault here is a small thrust with a strong drag zone. Gouge may be seen in the fault plane itself. Another small but tight fold succeeds the fault to the west. About 75 ft. from the small fault is an interesting overturned anticline with an east limb dipping only a few degrees to the east and a west 11mb dipping 75° to 80° to the east. As a result the beds on the west limb are up-side-down. For a distance of about 30 ft. is a zone of shattered siltstone which may represent one of the faults on the opposite side of the road. Still walking westward the last structure to be encountered is a symmetrical anticline whose limbs dip 30°. Jointing is obvious through the section.
In addition to the structural elements there are many sedimentary features to be seen on both sides of the road. Mud pebble conglomerates, large ripple-marks, graded bedding and other features may be observed throughout. It is also interesting to note the result of unloading of the surface upon the siltstones and graywackes. Here, the beds have fractured and it is possible to see the difference between the beds which are actually several feet thick and the zone in which the beds appear thinner due to unloading. Furthermore, it is obvious that the beds of siltstone and graywacke do not maintain a constant thickness as one traverses the outcrop.
Discussion
The primary cause of interest at the Clifton park anticline lies in the differences in strata and structural appearance on either side of the road. Some students have suggested that a fault, striking east-west is responsible for the disparity. This seems unlikely and is not needed to explain the exposure. On the contrary, an asymmetrical fold plunging to the southwest which was later cut by faulting seems to provide a simple and more adequate explanation. The explanation lies more in the asymmetry of folding followed by erosion than in any other factor. Certainly there is room for interpretation at this outcrop and we will welcome any comments.

STOP 2 Geyser Park and the "Vale of Springs"
Location
This area is a portion of the state-owned Saratoga Springs Reservation located just so~th of the city of Saratoga Springs, between N. Y. 9 on the east arid N.Y. 50 on the west. Geyser Park is situated in the western half. Entrance to the Park is via.a new road at the southern limits of the reservation which connects with both Route 50 and Route 9. The old entrance and approach to the Park, near the Hall of Springs, has been closed to vehicular traffic making it impossible to approach the. park from the north. Visitors may, however, elect to park in that section of the reservation and walk down the hill into the upper section of the Park.
Features and Lithology
This area has the highest concentration of "springs" and "geysers" of any area in or around Saratoga. Altogether four "springs" and three "geysers" will be in operation upon the completion of a multi-million dollar reconstruction program.
The mineral waters discharged by the "springs" and "geysers" are representative of the Saratoga type mineral water; a highly saline water charged with varying amounts of carbon dioxide gas. Occurrences of this type mineral water is restricted to only one other locality in the United States.
The wells in the Park,some almost 1,000 feet deep, continuously discharge large volumes of water. The water is carried up in the well by the release of gas pressure in much the same manner as a warm and well-shaken bottle of soda ejects its contents when opened.
This water pressure, passed through a small orifice at the top of some wells, produces the so-called "geysers" to be seen in the Park.
The large proportion of salts in the water, particularly carbonates, produces interesting tufa deposits in the form of cones, flows and terraces.
Geyser Brook, a non-carbonated, non-potable stream winds through the Park from the north, cutting a small valley and exposing the Canajoharie shales in several places. Rather poor specimens of some graptolites can be secured at several horizons in the shale.
Tour and Discussion
The first of three "geysers" to be observed is the Polaris "Geyser." All "geysers" are free flowing, but the force with which they leave the casing is regulated by using a small orifice. All of the "geysers" have been drilled and are actually wells which are allowed to run free. We have placed the word "geyser" in quotation marks since a true geyser is associated with hot water driven from the ground by steam pressure. Part of the cone of the Polaris has been created with stones piled around the casing, but a considerable amount of tufa (travertine) has been deposited since their initial operation.
The Park road eventually reaches a large parking lot, snack bar and comfort station. Further exploration will be on foot. Proceed across the bridge and turn right on the path. Just above the bridge is the Hayes Spring (well). The terminology becomes difficult at this point as both the spring and well apply. The impervious cap rock was pierced by a well in 1909. However, the water flows under its own pressure much as in a spring. Arguments could be collected in favor of an artesian well or spring. The reader is invited to choose one or the other. The Hayes is a pleasant water for those who are native to the area and who have acquired a taste for Saratoga type mineral water. It is well carbonated and moderately saline and popular with mineral water enthusiasts. A hole on the upstream side of the Fountain permits people to inhale the excess gas from the well and it is guaranteed to "clear your head." An analysis of the Hayes Well is appended for people with geochemical interests or for those who are just plain curious about what they are drinking. It is only fair to warn the drinker that many of the dissolved salts have had a reputation as "diuretics and cathartics," and they seldom fail to achieve this result when taken in any quantity. The "geyser" a hundred feet or so upstream is appropriately named the Island Spouter "Geyser." Its waters ascend in a graceful flow to heights of thirty feet or more and is a much photographed object. The tufa cone and surrounding terrace is no more than 40 years old but in that time it has acquired a considerable thickness. The terrace is very slippery and the water tastes the same as the Hayes. Since another terrace is more accessible, it is not necessary at this point to get any closer to it than you are.
A much larger and more impressive tufa flow occurs a few hundred yards upstream where the overflow from the Orenda "spring" cascades over the bank and enters the brook below. This action results in a vertical structure approximately thirty feet high and two to five feet thick. This tufa flow is, in a sense, a miniature Yellowstone of the east, with the notable exception that it is almost 93 percent carbonates from cold water rather than siliceous matter (silicates) from hot water. According to Strock, the travertine is built up at the rate of 0.5 gram/liter of water. Literally translated to English units, it works out to be one pound in 240 gallons, or a potential two tons per million gallons.
The terrace is an interesting physical structure but the tufa itself has a few singular features. First of all, it is radioactive. Minute amounts of radon and other radioactive materials dissolved in the water become highly concentrated in the tufa. The tufa also affords an open-air, above ground exhibition of cave type travertine formation. The rapidity with which it forms causes it to be more coarse and granular but the laminations are readily visible. The rapid formation of tufa gives rise to a sort of "instant fossilization" process. Twigs and leaves are quickly coated with the carbonates and become a part of the fossil record. Loose pieces of tufa show excellent imprints and faithfully record the botanical activity near the terrace. With some luck one can occassionally find an insect accumulating a calcareous overcoat.
Some of the shales on either side of the terrace have a few graptolites. These would be Ordovician but identification is difficult because of an absence of detail. The best horizons seem to range from two to five feet above the level of the path. Further upstream the path terminates at a bridge which crosses Geyser Brook as it emerges from a stone culvert which once carried the water beneath the now abandoned roadbed of the Delaware and Hudson Railroad. This is a very interesting area following a heavy rain; a prime spot to study the Venturi effect on the velocity of liquids.
The pipe discharging water into the stream at the southern end of the bridge is actually the water from the Champion spring (well). The well has sufficient pressure to be a "geyser" and was for a long time, and it may again function as such. The water is noticeably sulphurous in taste and smell, the only water in the Park to have this characteristic. Since this is not typical of Saratoga Mineral Wateor, we can assume that the casing has been perforated by corrosion and ground water is entering from the shales. Considerable quantities of sulfur water are encountered throughout the Canajoharie and Snake Hill shales much to the consternation of suburban Saratogians. At Saratoga Lake the waters become heavily charged with hydrogen sulfide. Luther's White Sulfur Springs, at one time, was a small spa itself but is unfortunately eclipsed by more famous sulfur springs to the west at Richfield and Sharon Springs. All sulfur water seems to be a product of the Ordovician Shales which outcrop in the Mohawk Valley from Utica eastward.
A second Champion "Spring" flows from the bank about 50 feet beyond the bridge. After crossing the bridge, the path climbs up the west bank and enters a road which passes south along the bank, passing the Orenda "Spring" whose overflow is responsible for the tufa terrace previously inspected. An excellent view of the Island Spouter "Geyser" is obtained along the road just before it descends to stream level at the Hayes Well and the parking lot. The Karista "Spring" is located a few hundred yards down stream on the west side of the brook from the bridge. Its mineral composition and gas content are much lower than either the Hayes or the Orenda. However, unless the visitor has a special interest in mineral water, it might be well to terminate the tour at the bridge and return to the parking lot.
The Saratoga Mineral Water Mystery
The manner in which this water was produced has excited the interest of many people and the theories seem to be directly proportional to the number of investigators. A few facts seem to have universal acceptance.
First, the water is in limestones and dolomites covered with the impervious layers of Ordovician shales which extend to the north, east and south. The Little Falls dolomite was given the credit for some time until Fisher and Hanson (1951) established the dolomite as Ordovician and renamed it the Gailor dolomite.
The water appeared at Saratoga because of an extensive fault (MacGregor) which forms a scarp north of Saratoga and then bifurcates as it approaches Saratoga. The eastern branch of the fault breached the shale and allowed the water to escape upward along the fault plane. This is graphically displayed at the north end of Saratoga Springs at High Rock Park. Route 9N traverses the top of the scarp and at the base approximately 30 feet of dolomite is exposed. High Rock Park is the site of the High Rock Spring, a true spring, which was known by the Indians long before Jacques Cartier first reported it in 1535. Only the tufa cone of this spring remains but a hundred yards to the north the Old Red continues to flow, having done so since 1774.
The control of the fault is striking. All springs and wells are always on the eastern side and the water issues forth at many places from Wilton, four miles north of Saratoga to Ballston Spa, seven miles to the south. Altogether some 200 springs and wells have produced Saratoga type mineral water, and always on the eastern side of the fault.
The source of the large mineral and gas content of the water has always been the difficult part of the problem.
Kemp (1912) looked to some deep-seated source for CO, Cl, Br and Fe. His ideas were deeply influenced by the presence of an old volcanic mass at Northumberland (Stark's Knob) some 15 miles northeast of Saratoga.
Strock (1944) on the basis of geochemical data, felt that the chemical content was in many ways related to sea water. As a result he placed the source in the Salina group, the extensive salt beds of Central-Western New York. Such beds extend eastward into Schoharie county, an area about forty miles to the southwest of Saratoga. Ruedemann-Cushing (1914) suggested that Saratoga waters originated to the east of the region, aided in their movements up the bedding planes and fractures of the limestones and dolomites by a hydrostatic head established in the Green and Taconic Mountains. The "volcanic exhalation" would doubtlessly furnish the CO2 but in all probability furnish other gases as well. It leaves a question as to the mineral matter and overlooks the lack of any thermal activity which in most cases might be associated with deepseated activity.
The virtual absence of all sulfates in the Saratoga water is difficult to correlate with the average chemical composition of sea water, either ancient or recent. Strock (1944) envisioned the water as coming down the Mohawk Valley and then moving northward. Unfortunately the dolomite outcrops long before it reaches the fault and in all probability would give up the water long before it reached the Saratoga fault. Then, too, it must be remembered that all wells and springs occur on the eastern side of the fault. The eastern basin theory seems to have fewer "ifs" and more positive evidence. The limestones and dolomites are buried at depth and covered by thick and impervious shales. The upturned edges of these beds, raised in the Taconic disturbance, collects the water. The limestones and shales are reasonably competent and withstood the compression of the Taconic disturbance without difficulty until it grounded out against the crystalline base of the Adirondacks. The north-south lineation of the fault would tend to substantiate this idea. This places the source of the water in the dolomites and limestones. Considerable amounts of sodium, calcium and magnesium salts are available plus the halogens which are noticeably high in the water. The Hoyt limestone beneath the dolomite contains a vast  Cryptozoon population which suggests shallow seas and possibly intermittent periods of dryness whereupon some elements would crystallize out and into the calcareous material of the sea floor. Any acid bearing ground water introduced into these carbonates would immediately begin an attack on the carbonates which in turn would begin the production of CO2. This gas, sealed in the acquifer by the shale above and brought up in pressure by a hydrostatic head, would produce a strong carbonic acid system which would increase with further solution until reasonably high pressures were developed. More than ordinary solution would occur, unlike the conventional solution as observed in other limestone areas. The water, driven westward by a hydrostatic pressure, reaches the fault and is carried up the thousand or more feet by the sudden release of the gas pressure. Colony (1929) in his report to the Saratoga Springs Commission examines all previous ideas and debates them in far more detail. Although the mineral water industry has declined seriously, the controversy as to its source and origin has flourished. Anybody with a new theory??
Selected References
Colony, R. J. 1929 Report to the Saratoga Springs Commission, Restudy of the Geology of the Saratoga Area and the Problem of the Mineral Waters. N.Y.S. Legislative Document #70, 1930.
Fisher, Dopald W. and Hanson, George F. 1951 Revisions in the Geology of Saratoga Springs, New York and Vicinity. American Journal of Science, Vol. 249, Nov. 1951, pp. 795-814.
Kemp, James F. 1912 The Mineral Springs of Saratoga. N.Y. State Museum Bull. No. 159, pp. 5-79.
Rudemann, R. and Cushing, H.P. 1914 Geology of Saratoga Springs and Vicinity. New York State Museum Bull. No. 169.
Strock, Lester W. 1944 Geochemical Data on Saratoga Mineral Waters-Applied in Deducing a New Theory of Their Origin. Publications of Saratoga Spa No. 14, 1944.
DEC Links 1 2 3

STOP 3 Stark's Knob
Stark's Knob is a protuberance of volcanic rock located north of the town of Schuylerville, New York. It was named after General John Stark of the Revolutionary Army that hindered Burgoyne's retreat to the north (Woodward, 1901). It is found 1.2 miles north of Schuylerville just west of New York State Highway #4. The Knob is a mass of'basalt about 200 feet high and is surrounded by Ordovician Normanskill shales. The rock has been quarried for road metal resulting in exposure of the interior of the rock mass. In describing the Knob and locating its features, it will be convenient to refer to the quarried face on the east and the natural face, which is a steep cliff, on the west. Prior to quarrying, the Knob was probably ovoidal or circular. It may be noted that basalt is also found on the south side of the dirt road located south of the Knob.
Standing at the base of the quarried face one can see a mass of dark basalt broken by many fractures and fault planes. A prominent fault or fracture extends upward along the middle of the quarried face. A less obvious fault exists about 50 feet up slope from a small circular well or pool at the base, near the southern corner of the quarried face. One can also see pillow lava or lava ball structure displayed allover the quarried face. The western natural face is almost vertical on its north end and is partially covered by talus on its southern end. The southern portion of the Knob is unquarried and is extensively covered by brush and trees. A foot path extends over the crest of the Knob. At the summit" a plaque offers the history of the area and a presumed explanation of the geology.
Rock Types
The basaltic Knob is surrounded by slaty shales of the Normanskill formation. The shales are blue-gray and weather to buff and locally rusty-red. Cleavage is well displayed, and bedding is obscure. The shale-basalt contact is exposed on a small hump at the base of the Knob along the dirt road leading to the quarry. The contact is also exposed along the northern end of the Knob at the edge of the quarry where it curves eastward, and in a small patch near the summit along a path leading down the talus slope of the natural face. No apparent macroscopic contact metamorphism of the shales has been observed. Some of the shales at these contacts may be fault slices or inclusions in the basalt.
Where the shales have been faulted, their character changes. This may be seen at the base of the quarry area and on a linear mound or hump which trends east-west at the base of the Knob on its southeasterly side (south of the quarry area). This mound will be discussed in the section on structure. The shales, which apparently have been faulted, do not show such prominent fissility as displayed in shales farther from the Knob. The rock has curved, platy surfaces and weathers rusty-red.
The basalt occurs as pillows) balls or ovoidal structures embedded in a matrix. Both the lava balls and the matrix are liberally penetrated by calcite veins. The pillows range from approximately an inch to four feet along the greatest dimension. They display radial jointing in the outer portions. The lava pillows are surrounded by a dark~ foliated~ shaly matrix. This matrix concentrically su~rounds and winds through the space between the pillows. Some pillows have a dark, glassy coating which in some places appears to be part of the matrix and at others, part of the pillow. Lava balls and limestone inclusions are beautifully displayed on the quarry face. Balls of varied sizes and shapes are randomly grouped. The balls show coarser grained interiors with a fine grained rind on the surface. In'rare cases they display characteristic pillow structure including the tail-like feature.
On the southeast unquarried portion of the knob the basalt does not show ball-structure as clearly. This rock is very porous, apparently due to leaching of calcite or some other mineral. There are many large and small holes in which lady bugs may be found hibernating during cold weather. This porous rock crumbles when struck by a hammer. Massive patches of basalt in which faulting is manifested by planes with slickensided calcite also occur on the unquarried portion of the knob. On both the quarried and natural faces the lava pillows contain amygdules. Many pillows, however, show no amygdaloidal structure.
Limestone inclusions may be found readily in the lava balls. The limestone is medium to dark gray and is medium to fine grained. The limestone weathers to buff or tan~ surrounded by a darker portion near contact with the basalt. Fracturing along calcite veins may give the appearance of a limestone inclusion. Care must be taken to make sure one is looking at an authentic inclusion. On the natural face the limestone is especially different from the quarried face. Here the inclusive nature of the limestone is less apparent and the limestone may actually be in the matrix. Locally a limestone matrix with basalt fragments appears as a breccia. The limestone itself is porous and is almost entirely calcite. An extremely small amount of fine, unidentified, insoluble residue was obtained from this limestone.
Structural Geology
The only secondary structures that can readily be seen in the basalt are fractures and faults. On the quarry side there are many ledges, over which one may walk, which exhibit slickensided calcite. Locally, calcite veins offset by fractures can be found. Along the crest over the quarry face there are fractures which are parallel or semi-parallel. Calcite veins occupy some of the fractures. Along this same crest and on the natural face the fractures are closer spaced than on the quarry side. Throughout the knob, calcite and quartz crystals occupy large fractures. Irregular calcite veins pervade the basalt and are not apparently related to fractures.
Faulting is manifested in the slickensides found along the calcite veins. At least some faulting must have taken place after the deposition of the calcite. There is one large fault plane or fracture striking N 500W and dipping 520 NE on the quarry side. It is covered with talus and vegetation making investigation difficult. Another prominent fault striking N 450W and dipping 320 NE is exposed above the small well just south of the quarry area. The rock here is crushed, folded and has a peculiar shaly appearance and is probably gouGe. There is basalt above the fault and talus below. Intersecting this fault almost perpendicularly is another fault which strikes N 650W and dips 790 NE. The fault surfaces here have very prominent slickensides.
The linear mound or hump mentioned previously strikes N 550E and plunges away from the Knob near the bottom of its southeast slope. The hump is about 12 feet across and 70 feet long. The rock exposed here is slaty shale but, as mentioned before, is different from the surrounding Normanskill shales.
Problems of Stark's Knob
This report is, of course, brief, superficial and almost entirely descriptive. It does not propose nor support any genetic theories for Stark's Knob. However, one cannot help but question the origin of this rock, and how it, unlike any other in the State, could have occurred here.
The main question concerning the orlgln of Stark's Knob is whether it is a volcanic neck, indigenous to this locality, or an allochthonous mass faulted in from some other area.
Cushing and Rudemann (1914) hesitantly support the theory that the knob is autochthonous and was intruded where it stands. Never the less, they acknowledge the apparent lack of contact metamorphism and the absence of any inclusions, especially shale, other than the limestone.
The irregular, fine grained calcite veins contrasted to the coarse, crystalline and slickensided ones may indicate more than one period of calcite precipitation. The pillow-type structure is similar to known subaqueous pillow lavas, hinting at under-sea extrusion of the basalt precipitating calcium carbonate dissolved in the water.
Bibliography
Cushing, H.P., and Ruedemann, R. 1914, N. Y. State Museum Bull. 169, p. 115-135
Woodward, J. B., 1901, N. Y. State Geol. 21st Rept., p. 17-24.
DEC Links 1