A1: LATE MIDDLE DEVONIAN BIOTIC AND SEDIMENTOLOGIC EVENTS IN EAST CENTRAL NEW YORK-TULLY FORMATION CLASTIC CORRELATIVE SUCCESSION IN THE SHERBURNE-ONEONTA AREA
Gordon C. Baird
Dept. of Geosciences, S.U.N.Y. Fredonia
Fredonia, NY 14063
Carlton E. Brett
Alexander J. Bartholomew
Dept. of Geology, University of Cincinnati
H.N. Fisk Laboratory of Sedimentology
500 Geology/Physics Bldg.
Cincinnati, OH 45221-0013.
ABSTRACT
Terrigenous clastic deposits equivalent to the upper most Moscow Formation and Tully Formation record a number of key sedimentological-paleontological events that occurred during the latest part of the Middle Devonian Givetian Stage. These deposits, last mapped in detail by G. Arthur Cooper and H.S. Williams in the 1930s, have been the subject of extensive stratigraphic mapping work by the present authors over the past five years. Goals of this mapping project are: 1) to identify divisions and boundaries correlative to units identified in the Tully Limestone further west through the classic work of Phillip Heckel in the sixties and seventies; 2) to identify key facies that can be interpreted in the context of onshore-offshore paleoenvironmental models; 3) to reconstruct the faunal succession in this thick interval of strata so as to elucidate in greater detail two key levels of faunal change associated with the global Taghanic Bioevent; and 4) to use stratigraphy and sedimentology to identify structural features that were active or present during deposition of these units.
Preliminary results of our work show that most of the lower and medial parts of the Tully Formation clastic correlative succession (here in referred to as "TFCCS") between Sherburne, NY and New Lisbon, NY consist of relatively unfossiliferous strata that record the development of a structural basin (New Berlin Trough) probably centered in what is now the Unadilla Valley. Condensed units overlying regional discontinuities developed at several stratigraphic levels both in the basin and on its western flank; sediment-starvation associated with condensation led to the formation of "oolitic" chamosite under conditions not fully understood. Basin center deposits recorded dysoxic conditions and development of low diversity faunas dominated by auloporid corals and small brachiopods; eastward passage of sparsely fossiliferous deposits near New Berlin to richly fossiliferous equivalent units near Laurens reflects a shoreward basin-to-shelf transition. This contradicts the standard view that the lower and medial Tully record primarily shallow and even lagoonal conditions. Our model does vigorously support (and significantly enhances) Heckel's (1973) view of a "Tully clastic trap" controlled by structure in east-central New York.
Herein, we show that typical oxic Hamilton facies ends with onset of dysoxic, highstand conditions associated with deposition of the New Lisbon Member. We exclude the upper, Tully-equivalent part of Cooper and Williams' (1935) "New Lisbon Member", which is separated from our restricted New Lisbon Member by a basal Tully erosion surface. Currently, we believe that the restricted New Lisbon succession is equivalent to the Gage Gully submember of the Windom Member, although this is still uncertain. The TFCCS contains six internal mappable discontinuities; these are, in upward-succession: a, a base-Tully (DeRuyter Bed-equivalent?) contact; b, a sub-"Laurens" contact, possibly equating to the base of the Fabius Bed to the west; c, a sub-Symrna Bed disconformity traceable westward into central New York; d, a top-Smyrna flooding surface contact; e, an erosion surface flooring the West Brook Bed; and f, a diastem (base-Moravia Bed? discontinuity) above the West Brook Bed. The upper Tully, base-West Brook contact marks the greatest lowstand event with development of a prolific Hamilton faunal association characterized by diverse brachiopods, and corals, above the contact. East of Otselic, the Tully Formation contact with the overlying Geneseo Black Shale is conformable.
Initial Tully Fauna incursion occurs at the base-Tully (DeRuyter Bed-equivalent?) contact at New Lisbon and Laurens. The Tully Fauna persists above the Smyrna Bed into the middle part of a sparsely fossiliferous post-Smyrna Bed highstand-succession probably correlative with the Taughannock Falls Bed within the Tully Limestone. The uppermost part of the highstand succession is characterized by a return of the pre-Tully Hamilton fauna. The West Brook Bed records a major, anomalous acme ("last hurrah") of the Hamilton Fauna prior to onset of dysoxic and, finally, anoxic conditions associated with uppermost Tully and Geneseo deposition. Preliminary work on eastern sections of the TFCCS suggests that nearshore, Tully equivalent "Chemung-type" facies may yield several taxa of the Ithaca fauna absent from outer shelf, Tully platform carbonates.

A1: LATE MIDDLE DEVONIAN BIOTIC AND SEDIMENTOLOGIC EVENTS IN EAST CENTRAL NEW YORK-TULLY FORMATION CLASTIC CORRELATIVE SUCCESSION IN THE SHERBURNE-ONEONTA AREA

STOP 1. Tully Shale Borrow Pit at Tully Center (20 minutes).
Windom Fauna and Basal Tully Contact.
This well known stop for professionals and amateurs alike is best known for diverse taxa of the Hamilton Fauna that occur in strata of the Windom Member. Windom divisions exposed here include; in ascending order: The Taunton submember (25 feet); the Lansing Coral Bed (1.5 feet); the Spezzano submember (5 feet); the Gage Gully submember (8 feet); and the Sheds submember (6 feet). The Taunton submember is a shoaling (RST) interval. The Lansing probably marks the base of a subsequence interval. All of it (or part of it) commences a transgressive (TST) succession that continues through the Spezzano submember and into dysoxic early highstand facies of the lower Gage Gully submember. The Sheds marks the return of shoaling condition followed by another transgression recorded by the newly defined Highland Forest submember (here absent due to erosion) that is represented by dysoxic Emanuella-bearing strata (Baird and Brett, 2003). Diverse Hamilton taxa (too numerous to discuss here) are characteristic of the shallower facies. Dysoxic taxa, represented by Eumetabolatoechia ("Leiorhynchus") multicostatum, Emanuella praeumbona, and diminutive Allanella tullia are characteristic of the dark gray Gage Gully submember. Not discussed in most earlier reports is the occurrence of the basal layer (DeRuyter Bed) of the Tully Formation at the top of this section. This bed is represented by a 0.3 foot thick layer of impure limestone abounding in the characteristic lower Tully strophomenid Rhyssochonetes aurora and scattered phosphatic pebbles. This layer rests disconformably on the Sheds submember; at Junes' Ravine, 1.3 miles east-northeast of this section, the topmost division of the Windom Member (here eroded) is represented by the Highland Forest submember. At Junes' Ravine it is represented by 0.9 feet of silty, calcareous shale rich in Emanuella, small Tropidoleptus, small Allanella, and Mucrospirifer.

View of Tully Lakes (Kettle Lakes) to left (south).
Song Mountain Ski complex in distance. For the next 1.8 miles we will cross the Tully Valley on the Valley Heads Moraine. Notice the elevated drift-floored plain to the south and the approaching bedrock valley wall to the west.

STOP 2. Tully Limestone Divisions in Driveway Section Next to Carrs' Creek- Quarry Locality.
The Carrs' Creek-Quarry section serves to illustrate the typical, prominent carbonate succession of the Tully Formation in west-central New York. Fortuitous excavation of the new driveway and the kindness of the owners who built it, preclude our need to climb the slippery creek section. Moreover, the driveway cut reveals weathered joint surfaces that show excellent textural details and fossils. The driveway section exposes in upward succession: the Fabius Bed (3 feet visible), the Meeker Hill Bed (3.75 feet), the Tully Valley Bed (1.5 feet), the Vesper Bed (1.5 Feet), the Carpenters Falls Bed lower part (3.4 feet); the upper part of the Carpenters Falls Bed separated from the lower part by a discontinuity (0.5 feet); the Taughannock Falls Bed (2. 7 feet); the Bellona Coral Bed (0.3 feet); and the Moravia Bed (2.75 feet visible). Basal Tully units visible in the creek but not along the driveway include: the DeRuyter Bed, the Cuyler Bed, and the lower part of the Fabius Bed.
The present authors believe that the lower part of the Tully Formation succession (DeRuyter Bed-to-the-intra Carpenters Falls discontinuity) records an interval of overall shoaling with increased Tully Fauna diversity upward (see text; Baird and Brett, 2003). The topmost Carpenters Falls Bed and the Taughannock Falls Bed (medial Tully succession) records a time of relative deepening following the intra-Carpenters Falls lowstand event. This is roughly timed with the demise of the Tully fauna and redevelopment of the Hamilton Fauna (see text; Baird and Brett, 2003). A second regressive episode is recorded by the Bellona Bed. The Bellona "coral plantation" (sensu Heckel, 1973), yielding large rugosans and tabulates such as Favosites and Alveolites at this locality and others further west, records maximum return of the diverse Hamilton Fauna Biota. Actually, the basal 0.5 feet of the overlying Moravia Bed is composed of dark limestone yielding corals and Spinatrypa; we believe that is interval correlates eastward to a limestone bed that caps the West Brook Shale (Figures 5, 6).
The five-six inch thick topmost part of the Carpenters Falls Bed is characterized by "oolitic" grains somewhat resembling chamositic "ooids" in the Smyrna Bed to the east. Moreover, the top of this interval displays fracture systems resembling the "mudcracks" reported by Heckel (1973). Most significant is the presence of laminated carbonate texture resembling algal (microbialite) stromatolites (see text discussion). We believe that these structures underlie Heckel's (I973) regional "intra-Tully unconformity" which we interpret as a flooding surface. We also argue that the topmost part of the Carpenters Falls Bed, as presently defined, overlies a lowstand disconformity and may be the western equivalent of the Smyrna Bed (see discussion).

Type Tully Formation section (Junes' Ravine) to the north (left) in the uphill woods.

Excellent view of glacial U-shaped profile of Labrador Valley to right (south).

STOP 3. Tully Fm sections adjacent to Highland Forest Metropark HQ.
The fortunate location of this section allows for the use of lavatory facilties and time for box lunch consumption. Two Tully sections can be studied, time permitting. The first, below a trail bridge near the parking lot and bordered by paths, will be the main object of attention. This exposes all of the Tully Formation except a portion of the Fillmore Glen Bed-interval near the top of the Tully. In this region, a prominent regional disconformity, first characterized in detail by Heckel (1973) is observed to divide the Tully succession. The lower Tully succession (DeRuyter Bed-into-Carpenters Falls Bed interval) is observed to be overstepped rapidly eastward from the meridian of Highland Forest Park such that no lower Tully is observed in sections east of the meridian of Sheds. This erosion was believed to commence eastward from the level of the post-Carpenters Falls "intraformational unconformity" southeast of Fabius (Heckel, 1973; Figures 2, 3). From DeRuyter Reservoir eastward, this disconformity surface was believed to coincide with the base of the Smyrna Bed (Heckel, 1973) that is traceable to the Sherburne area. The present authors connect the regional, sub-Smyrna disconformity westward, not to the post-Carpenters Falls contact, as did Heckel (1973), but to the base of what Heckel termed "Carpenters Falls Bed" in the Fabius-Labrador Valley area (Baird and Brett, 2003). The thin "Carpenters Falls Bed" interval of the Fabius-Labrador Valley region is a sandy, abraded grain encrinite characterized by a sharp irregular base marked by giant hypichnial burrow prods and minor phosphorite. Careful examination of sections between Fabius and DeRuyter shows that this unit is present in most sections across the region and that it connects laterally to the Smyrna Bed. At this locality, this bed is present, but is of variable thickness; under the walk bridge it is only a few inches thick, but, at the adjacent south fork section, it is almost a foot-thick. This may reflect local Smyrna Bed cutout beneath the sub-Taughannock Falls Bed flooding surface contact. The intra-Carpenters Falls discontinuity at Stop 2 may connect to the sub-Smyrna disconformity.
Another major aspect of the lower Tully succession in this region is that the Fabius Limestone Bed at Stop 2 has transformed into a calcareous siltstone-silty limestone unit and the underlying Cuyler Bed has thickened considerably. In contrast, much of the upper Tully succession consists of clean limestone and clay shale. This is a major facies change described in detail by Heckel (1973). He related it, in part, to terrigenous sediment-sourcing from the region of lower Tully erosional cutout between DeRuyter and Sherburne (Heckel, 1973).

Cross Limestone Creek. Morainal deposits exposed in creek banks.

East valley rim of Limestone Creek.
Valley head moraine plain for next 0.4 miles.

STOP 4. Tully Formation Roadcut and Road Ditch Section
Showing Complete Overstep of Lower Tully Member Division by Sub-Smyrna Bed Disconformity.
This section displays the two uppermost submember divisions of the Windom Member overlain by units of the upper Tully Formation succession. The upper part of the Sheds submember is visible in the lowest 2-3 feet of the bank and yields numerous Hamilton Fauna brachiopods and clams. This is abruptly overlain by 2.5 feet of Highland Forest submember that is characterized by siltstone beds and a low diversity association of Emanuella praeumbona, small Tropidoleptus and Mucrospirifer. This section exposes the highest strata of the Windom below the Tully in central New York, although considerably thicker Highland Forest sections are observed in central Pennsylvania (Baird and Brett, 2003).
The visible Tully succession rests disconformably on the Windom. At this locality the basal 16 inches of the Tully is represented by the Smyrna Bed, a hard overhanging ledge composed of abraded calcarenite and minor "oolitic" chamosite. This bed displays a sharp base with development of large hypichnial burrow prods filled with encrinite, minor sand, minor phosphate, and chamosite. Lucky persons will find clusters of 3-D Tullypothyridina in some of the basal protruding burrows. As noted by Heckel, 1973, the lower Tully succession is absent due to regional overstep by the sub-Smyrna disconformity. This overstep is characteristic of Tully sections eastward to the Sherburne area. Post-Smyrna strata are represented by an expanded shale-limestone phase of the Taughannock Falls Bed interval. In the road ditch, strata of the West Brook Shale and its capping limestone unit can be seen. These units yield many Hamilton Fauna taxa. Excellent trilobite fossils, camerate crinoids and blastoids are found in this interval.

Pass Spirit House on left.
Special ornamentation and rounded corners were devices designed by owner to fool the Devil.

Notice major exposure of medial Windom Member/Cooperstown Member
Notice major exposure of medial Windom Member/Cooperstown Member strata on floor of Pleasant Brook to the right.

More visible Moscow Formation strata on floor of Pleasant Brook.
Major Tully Formation exposure (Upperville section: Locality 1) is across brook on along a tributary.

Pass Rogers Nature Center.
Geese, giant carp, and snapping turtles can be viewed from a bridge near the parking lot.

Cross Chenango Creek.

STOP 5. Thin, condensed Tully Formation Section
On "Sherburne High" Structural uplift.
This is an important section (Locality 9) described in Cooper and Williams (193S) and Heckel (1973) publications. This is the type section of the West Brook Shale, a nearly three foot-thick unit of calcareous shale abounding in diverse Hamilton Fauna taxa recorded in extensive faunal lists (Cooper and Williams, 1935, Heckel, 1973). It is the "last hurrah" for the Hamilton Fauna prior to the gradual onset of transgressive anoxia associated with Geneseo black shale deposition.
Eastward erosive downcutting of Hamilton Group strata by the sub-Smyrna Bed disconformity places the Cooperstown Member-Tully Formation contact on the Spezzano submember interval of the Cooperstown (Figures 5, 6). The Smyrna Bed at this locality is a 4-5 inch-thick unit of"oolitic" chamosite and subsidiary sandy, bioclastic abraded calcarenite that rests disconformably on underlying Hamilton Group deposits (Figures 5, 6). Discoidal dark gray to black, sand-sized chamosite grains dominate over subsidiary phosphorite pebbles and rare shells within the bed. Though not encountered by the present authors, Heckel (1973) reports a cluster of Tullypothyridina within the Smyrna Bed. Above the Smyrna Bed is a 2.2 foot interval of hard, slabby siltstone or fine sandstone facies yielding few fossils. Heckel (1973) referred to this unit as the "unnamed sandstone." Above this unit is a complex interval of "oolitic" chamosite, tabular siderite and limestone comprising the interval between the "unnamed sandstone" and the basal contact of the West Brook Shale (Figures 5, 6). Heckel (1973) referred to this interval of the "Taughannock Falls Oolite Bed" and indicated that it was a condensed lateral equivalent of the Taughannock Falls Bed (Heckel, 1973).
Careful work by Baird and Brett (this paper) shows the probability that Heckel's (1973) correlation is correct. However, the disjunct character of section match between localities 3 and 4 (Figure 5A) and localities 12 and 13a, b (Figure 6) offer the possibility that the Smyrna Bed near Smyrna (Localities 1, 2) and Sherburne Four Corners (Locality 3) may actually connect to the "Taughannock Falls Oolite Bed" rather than the lower chamositic layer (Figure 5A). Thus, from Cush Hill Road (Locality 4) to Harrisville (Locality 12), it is possible that a part of the lower Tully Member (Fabius Bed?) may be represented by the lower chamositic layer and the "unnamed sandstone" (Figure 5, 6). Both chamositic beds are well developed at this locality. Chamosite, an iron-rich silicate, of somewhat problematic origin is characteristic of several Tully (and even pre-Tully) levels in east-central New York. The absence of chamosite in western New York and east-central New York sections shows the occurrence of this mineral to be restricted to a particular depositional belt (see text discussion). The absence of common robust fossils in chamositic beds, the mud-rich character of some chamosite-rich layers, and the occurrence of chamosite in dysoxic facies yielding "leiorhynchid" -type rhynchonellid brachiopods suggest that the origin of this unusual deposit may be some physical (or diagenetic) process occurring across a range of outer shelf and dysoxic, sediment-starved environments (see discussion).

Cross Mad Brook. Upper part of Cooperstown Member exposed below bridge.

Major "Perrytown" section (Locality 17)
Fairkit Farm to left. Major "Perrytown" section (Locality 17) of Tully clastic correlative succession (see Cooper and Williams, 1935; Heckel, 1973) high up on hill to the south.

STOP 6. Thick Tully Clastic Correlative Succession Along Unnamed Creek
(Locality 18) parallel to, and east of Balcom Hill Road.
Cooper and Williams (1935) and Heckel (1973) devoted considerable discussion to the first thick clastic Tully outcrop ("Perrytown" section) that was encountered proceeding east from the area of thin Tully occurrence on the "Sherburne High". That outcrop (Locality 17) is too far from any road to be visited on this trip. However, another adjacent section (Locality 18; Figure 7) that is almost as complete is herein included as a stop. We will intersect this creek at the topmost exposed Cooperstown Member above a small falls. The upper coral layer of the Lansing Bed is 15 feet below the falls lip and the strata comprising the falls is probably equivalent to the Spezzano submember in the Windom (Figures 7, 11). A six foot covered interval follows the Cooperstown succession that is, in turn, succeeded by 5 feet of lower Tully strata and about 45 feet of continuous upper Tully section. At the adjacent "Perrytown" section (Locality 17) part of the New Lisbon Member is exposed, as is the base of the Tully clastic succession above the New Lisbon (see text; Figure 7). The basal Tully contact on that creek is characterized by chamosite, nodular diagenetic siderite, and Tully Fauna taxa (Hypothyridina, Schizophoria, Spinatrypa), probably corresponds to what we call the "base-Laurens" disconformity (see text discussion). Heckel, 1973, (Figure 3) tentatively correlated this bed to (or near) the position of the Smyrna Bed in the Sherburne area.
However, on that same creek, and on this section as well, there is a second, more complex and prominent bed characterized by calcareous, auloporid-rich sandstone in the lower part and nodular chamositic limestone and siderite in the upper part (Figures 7, 10). The present authors correlate the upper part (and tentatively the lower part) of this unit to the Smyrna Bed instead (Figures 7, 11 ). The coarse, hashy mix of fossil debris and the nodularity of the carbonate component are texturally similar to the Smyrna Bed though the unit is sandier overall.
Although the "base-Laurens" disconformity is covered here and the underlying New Lisbon is concealed (or absent due to overstep: see text discussion and Figures 7, 11), we will see higher divisions of the lower Tully clastic succession. A massive two foot-thick siltstone bed exposed above the covered interval may correspond to part of the Fabius Bed. Above this, participants can view the 8-inch-thick nodular, calcareous auloporid-pelmatozoan-rich sandstone ledge of the lower Smyrna Bed. Calcareous chamosite and diagenetic siderite are characteristic of the upper Smyrna (Figures 7, 10). This is a condensed, presumably transgressive, phase probably corresponding to a major mid-Tully deepening event. In this interpretation the lowstand (sub-Smyrna) erosional contact is understood to be at the base of the chamositic bed or at the base of the 8-inch auloporid-rich sandstone (Figures 7, 10).
Above the Smyrna Bed is a 37 foot-thick interval of flaggy to slabby thin siltstone beds with shale interbeds. With exception of a thin medial layer, the Walt Phillips Bed, this interval yields very few macrofossils. Auloporid corals, sparse pelmatozoan debris, plant fragments and the occasional mollusk comprise the observed biota. We will view this interval at greater advantage at Stop 7. The present authors correlate this thick "barren" unit to the Taughannock Falls Bed in the Tully Limestone, although the upper part of it may be missing due to regional overstep to the west of this area (Figure 11).
One may properly question correlations based mainly on lithologic and textural parameters and minimally on distinctive guide fossils. We acknowledge this problem with numerous caveats, but have to point out that lower and medial Tully deposits in this area are conspicuously poor in fossil content. Although Tully Fauna taxa occur both in the lower and medial Tully, they are uncommon to rare. Even in the Sherburne area, the chamositic beds contain few shells and these are mostly small. The only unifying taxon that characterizes this facies is the auloporid coral that abounds in the condensed units. In fact much of the Tully clastic correlative succession in this area resembles portions of the Penn Yan and Sherburne members of the Genesee Formation. It is, thus, not surprising that Thayer (1974) described the biota of the dysoxic prodelta slope facies of the Genesee Group as the "Cladochonus" (auloporid) biofacies. As such, we interpret this region to be a structural subsiding basin relative to a platform setting for the Tully Limestone further west.
Another line of evidence for subsidence of this area is the dramatic thickening of Tully units and the reappearance of lower Tully beds east of the "Sherburne High" (Heckel, 1973). Heckel (1973) correctly envisioned a "down-to-the-east" fault and a clastic trap within the basin that prevented clastics from overspreading the Tully platform. We confirm this model (Figures 5 - 8) but show that lower Tully beds are, again, overstepped to the southeast of this section before re-emerging to the east of New Berlin (Figures 6, 8). At the upper end of this transect, we will see the West Brook Bed and a capping discontinuity probably corresponding to the base of the Moravia Bed. The West Brook is richly fossiliferous and astonishingly thin relative to surrounding units. Corals, diverse brachiopods, bryozoans and other stenotopic Hamilton Fauna taxa can be found here. The West Brook has an erosional base marked by burrow prods and encrinite; this contact marks a significant lowstand event and it is responsive for conspicuous overstep of the medial Tully section west of this locality (Figures 6, 7).

STOP 7. Walt Phillips Bed and Associated Medial Tully Strata
On Roadcut Along Walt Phillips Road (Locality 16).
This short stop serves to show the sparsely fossiliferous medial Tully clastic interval in good light. In particular, this outcrop is the type section of the Walt Phillips Bed a 16 inch-thick double-ledge interval of bioturbated siltstone that can be regionally correlated across the Columbus area (Figures 6, 7). At this section, this unit is at least 10 feet below the sub-West Brook disconformity. At locality 15, 0.5 miles northwest of this section, the Walt Phillips Bed is 18 inches below that contact and at locality 17, 0.9 miles east of this section, it is 17 feet below the West Brook. This pattern shows that there is a major trend of westward erosional overstep of the medial (Taughannock Falls Bed equivalent?) Tully succession below the sub-West Brook disconformity (Figures 6, 7, 11).
The Walt Phillips Bed is notable for the highest occurrence of Rhyssochonetes aurora in this region. It is a rare component along with Emanuella subumbona and scattered auloporids within the bed. This distribution shows that a diminished Tully Fauna component did survive within the Tully well past deposition of the Smyrna Bed. In the creek below the road is an incomplete in-place succession of lower Tully beds probably corresponding to the Fabius Bed succession to the west. In addition to this, however, are large loose Tully blocks derived from the till upstream from the actual outcrop. One of these blocks, resembling the lower Smyrna auloporid-rich sandstone unit at Stop 6, is capped by a thin, chamositic limestone bed yielding abraded calcarenite with auloporids, and rare Rhyssochonetes. Moreover, this bed displays "mudcrack" -like fractures and well-developed microbialite stromatolites similar to those originally described by Heckel (1973) along the intra-Tully discontinuity at Bellona and those observed by the present authors in the Tully Valley (see Stop 2). We believe the loose block to be a Smyrna Bed erratic and that the stromatolitic bed is associated with the top Smyrna transgressive flooding surface (see text for discussion).

Strata of lower part of Cooperstown Member
Strata of lower part of Cooperstown Member in stepped ramp falls in floor of Center Brook to the right.

Cross Otselic Creek

Cross Unadilla Creek, leave New Berlin and enter Otsego County.

Creek to left displaying Cooperstown Member
Creek to left displaying Cooperstown Member strata including two separated ledges of the Lansing Coral Bed.

Borrow pit on right displaying strata of Sherburne Member.

Upper Tully Fm clastic correlative succession
Upper Tully Fm clastic correlative succession in creek (Locality 26) below road on left.

Borrow pit on right displaying Sherburne Member strata.

Butternut Valley to right.

Cross Butternut Creek.

STOP 8. New Lisbon Member Type Section
And Higher Tully Clastic Correlative Units in the Vicinity of Otto Stahl Road.
This section (Locality 34 of present paper) was the focus of detailed study by Cooper and Williams (1935) particularly for definition of the New Lisbon Member. However, a long and nearly complete section of the Tully clastic correlative succession is also present along and near this creek. Cooper and Williams (1935) established the New Lisbon Member as a 60-foot-thick succession of flaggy siltstone beds and shale interbeds rich in the brachiopod Camarotoechia ("Leiorhynchus") mesacostale. The lower-middle part of the type section of this unit is exposed on adjacent Stony Creek (Locality 32) and the upper 38 feet of Cooper and Williams (1935) original "New Lisbon Member" is present at Stop 8. Cooper and Williams (1935) and Heckel (1973) both recognized that this unit was pre-Tully in its lower half and Tully equivalent (yielding Rhyssochonetes and Tullypothyridina) in its upper half. Thus, this unit filled the interval between the underlying Cooperstown Member, yielding Pustulatia ("Vitulina"), and fossil-rich strata of the overlying lower-middle Tully succession ("Laurens Member" of Cooper and Williams, 1935; Figures 1, 3).
As noted in the text, the present authors have found a chamosite-bearing bed on this creek yielding Rhyssochonetes, rare Hypothyridina, conularids, and abundant Emanuela 28.8 feet below the base of the "Laurens Member" and 10 feet above the lower end of this outcrop (Figure 7). This unit, located nearly at road level in the creek, is herein taken to be the base-Tully contact (Figures 7, 11). Moreover, a chamosite-rich contact bed is now observed to floor the New Lisbon interval at nearby locality 31 allowing us to formally bracket the unit with physical contacts (Figures 7, 11). With this new information, we herein restrict the New Lisbon Member to include only pre-Tully highstand deposits between the two chamositic beds (Figures 7, 11). The "upper New Lisbon" of Cooper and Williams (1935) is herein included in the basal Tully clastic succession. We agree with Heckel (1973) that the 28.8 foot-thick succession of C. mesacostale-rich slabby siltstones and sandstones in the abandoned quarry and creek walls near the car pull off probably corresponds respectively to the DeRuyter and Cuyler beds in the Tully Limestone. Also significant is the fact that this pre-"Laurens Member" Tully interval appears to be absent in all localities between this section and Sheds (Figures 7, 11).
A few hundred yards east (uphill) from the car pull off are a few small road ditch cuts in the "Laurens Member" succession. The first of these exposes a 20 inch-thick silty mudrock unit abounding in Emanuella, Echinocoelia?, Hypothyridina, Schizophoria, Spinatrypa, and Mucrospirifer. This corresponds to Cooper and Williams, 1935, "second shell bed" of section parlance. 14 feet further up the road is another bed yielding abundant, well preserved Tullypothyridina and Pseudoatrypa. This is Cooper and Williams' (1935) "third shell bed" of the section. Finally, 12 feet above that unit is a thin, shell hash bed rich in Emanuella, Echinocoelia?, large burrow prods and phosphatic pebbles. We tentatively link the first shell bed in the road ditch to part of the Fabius Bed and one (or both) of the two higher shell beds to the Carpenters Falls-Smyrna bed interval in the Tully Limestone (Figures 7, 11).
Higher strata of the clastic Tully succession can be viewed only from private land in the creek. Hence, we will not see this part of the section. It is worth noting that the West Brook Bed is spectacularly developed on the south fork of this creek and is floored by an eleven-inch-thick clean, crystalline calcarenitic limestone bed yielding rugose and tabulate corals. It appears that there is eastward overstep of medial Tully strata by the sub-West Brook disconformity beneath this limestone layer.

Strata of medial Tully Fm clastic correlative succession visible in creek falls to the right.

Cross north fork of Stony Creek tributary.

Entrance to Gilbert Lake State Park on the left.

"Houghtelings Glen" section of Cooper and Williams, 1935, to right.
This outcrop (Locality 38) exposes an excellent lower Tully Formation clastic correlative succession (see text) and was intended as a stop. However, a major windstorm has tumbled trees blocking the stream course for the immediate future.

Region of smashed and toppled trees.
This was the result of the same tornado (or downburst) that flattened trees at "Houghtelings Glen."

Hamlet of Milford Center. Susquehanna Valley to left.

View of Goodyear Lake to left.

STOP 9. Tully Clastic Correlative Succession
(or Tully equivalent Gilboa Formation) on South Side of Route 28 by Goodyear Lake.
This is a "floating section" probable corresponding to part of the middle-upper part of the "Laurens Member" (Cooper and Williams, 1935). About 35 feet of section is exposed; spectacular flow rolls (seismites?) are visible in the lower third of the section; about two thirds-up is a 20-inch bed rich in Tullypothyridina, Echinocoelia, Mucrospirifer, Spinatrypa and bivalves. In the topmost 5 feet, pelmatozoan debris is prominent at several levels. This section, and, to a lesser extent, Stop 8, stand in stark contrast to the sparsely fossiliferous sections (Stops 5, 6, 7) of lower-middle Tully facies in the Sherburne-New Berlin area (Figures 7, 8, 11). We hypothesize that a structural, bathymetric trough centered at New Berlin separated the Tully carbonate platform in west-central New York from a sandy shelf area in eastern New York (Figure 12). Hence, the coarse, fossil-rich, Tully clastic deposits of the Otego and Susquehanna Valleys corresponds to the "Chemung" facies belt for the Taghanic Stage (Baird and Brett, 2003). Current explorational work is directed to localities in this valley and further east to characterized both the biofacies and stratochronology of this poorly known interval. We hope to determine whether inner shelf biotas at the Taghanic level have a unique taxonomic composition or correspond to the Ithaca Fauna of overlying units. A great final mystery is centered on the relationship of various marine units (Cooperstown Member, clastic Tully succession, and Geneseo Member) to the Gilboa Formation. This problem is beyond the scope of the present report, but is the subject of ongoing investigation (see Bartholomew and Brett ???).

Sunday extra stop

STOP 10. Tully Fm Section on Taughannock Creek.
Type Section for the Taghanic Stage.
This outcrop provides an excellent look at the Tully Formation section and adjacent units. Several feet below the base of the Tully is the westernmost occurrence of the Lansing Coral Bed; Favosites, Heliophyllum and other corals can be found as well as large fistuliporoid bryozoans and diverse brachiopods. The Spezzano submember is recessive below the disconformable base of the Tully. Large hypichnial burrow prods characterize the basal Tully surface where the Hamilton shale has eroded away below it. The remaining Tully succession to the base of the 5-foot-thick Fillmore Glen succession is massive, dove-white weathering fine limestone that is clean enough for quarrying as is done at Portland Point across the lake. Key interval units and contacts will be pointed out at this stop.
This is the key reference section for the Taghanic provincial stage, the Taghanic Unconformity and the Taghanic bioevent (see Johnson, 1970; Heckel, 1973; Aboussalam and Becker, 2001; Baird and Brett, 2003). However, it is significant that this Tully section is very incomplete due to westward erosive beveling of most lower Tully strata between Skaneateles Lake and this locality (Heckel, 1973). As such, the Carpenters Falls Bed, yielding Tullypothyridina and other lower Tully taxa, rests disconformably on the Hamilton. This is Johnson's (1970) "Taghanic Unconformity" which was believed to mark the start of a major craton-ward stratigraphic onlap event. Careful examination of higher Tully in western New York suggest, however, that the lowstand base-line for the transgressive Taghanic onlap event is at a higher level within the upper Tully Member or near the top of the Tully (Baird and Brett, 2003). The lowstand base-line for the upper Tully TST interval is the regressive Bellona Coral Bed and the actual transgressive onlap is understood to commence at one or more horizons bounding (or within) the Fillmore Glen Bed (Baird and Brett, 2003). The top-Moravia Bed omission horizon (knobbly surface) and five calcilutite-shale repetitions comprising the Fillmore Glen succession are well displayed at this section. Note the black, fissile strata of the Geneseo Member in the bank walls. This unit records major transgressive deepening in the foreland basin owing to combined effects of eustatic transgression and thrust loading to the east (Johnson et al., 1985; Ettensohn, 1998). Higher outcrops of this unit and overlying deposits, exposed in the great fall on this creek, are worth seeing, but are too far upstream to be accessed on this trip.

STOP 11. Tully Limestone section on Kashong Creek
Stromatolites Above Mid-Tully Unconformity; Bellona Bed; Undulatory Top-Tully Erosion Surface.
We will descend into Kashong Creek upstream from the bridge and proceed to a breached up-fold of Tully in the creek floor. Along the contact between the underlying Carpenters Falls Bed and the overlying Taughannock Falls Bed is a layer of fracture networks, domal limestone knobs and stromatolitic carbonate deposits filling low areas peripheral to the knobs. This is Heckels', 1973, stromatolitic horizon associated with his regional intra-Tully unconformity. Close examination of the stromatolite texture shows that the lamination is arrayed concentrically around the structureless limestone knobs and parallel to fracture networks. Very close examination of the laminite shows that it has a perpendicular "pillared" microstructure that is normal to the visible lamination, a characteristic that Heckel, 1973, also noted. The stromatolitic layer is usually only millimeters-thick in swales and it is erosionally breached over knobs. The base of the stromatolitic layer contains skeletal debris, pyrite, phosphate grains and some fish bones; this marks the horizon of the discontinuity surface. It is important to compare the stromatolitic surface at this locality with material from Stops 2 and 7 as these latter occurrences are believed to be essentially the same level.
Several feet above the stromatolitic horizon is the Bellona Coral Bed which is thin, muddier than surrounding Tully facies, and profusely fossiliferous. Where it is swept clean on bedding surfaces, hundreds of corals can be seen. Easily spotted taxa within the bed include: Heliophyllum, Cystiphyllum, Favosites, Alveolites, and the brachiopod Spinatrypa. This is the "coral plantation" of Heckel, 1973, that serves as a key datum in mapping over huge areas. Above the Bellona Bed are clean carbonate deposits of the Moravia Bed. However, Heckel, 1973, correctly noted that the top-Tully contact at this locality is undulatory. Up to a foot of Moravia is present above the bridge, but, below the bridge, the Geneseo black shale rest directly on coral-rich Bellona deposits.
The Geneseo Member rests on the Tully with knife-sharp definition. Tully carbonate is locally separated from the well-jointed Geneseo by a thin lag bed of pelmatozoan calcarenite, but not detrital pyrite or bone debris. However, at Gorham, the next section to the west, detrital pyrite and bone debris characteristic of the Leicester pyrite rests on the Bellona Bed. Still further to the west, the base-Geneseo corrosional discontinuity is observed to cut out the Tully Formation and truncate the topmost beds of the Windom Member (Baird and Brett, 1986). The occurrence of channel-like grainstone lentils within the Geneseo Shale 16 inches above the Tully contact at Bellona, suggest the possibility that the real Leicester horizon is actually within the basal Geneseo on this creek and that the observed Tully-Geneseo contact at Bellona is a pre-Leicester surface that may project eastward to some level within (or at the base of-) the Fillmore Glen Member. This issue is still being investigated.