The Pennsylvania State University
The Graduate School
College of Earth and Mineral Sciences
ORGANIZATION AND DISTRIBUTION OF MIDDLE DEVONIAN BIOFACIES
WITHIN A SEQUENCE STRATIGRAPHIC FRAMEWORK,
HUNTINGDON COUNTY, PENNSYLVANIA, USA
A Thesis in
Geosciences
by
Travis J. Deptola
© 2012 Travis J. Deptola
Submitted in Partial Fulfillment of the Requirements for the Degree of
Master of Science
December 2012 The thesis of Travis J. Deptola was reviewed and approved* by the following:
Mark E. Patzkowsky Associate Professor of Geosciences Thesis Advisor
Rudy L. Slingerland Professor of Geology
Peter D. Wilf Associate Professor of Geosciences
Lee R. Kump Professor of Geosciences Department Head of Geosciences
*Signatures are on file in the Graduate School.
ii ABSTRACT
Understanding the controls on the distribution of fossils in time and space is a
fundamental aspect of paleontological research, because it underlies studies of ecosystem change
through time, patterns of origination and extinction, and the geographic distribution of diversity.
In the marine fossil record many studies have investigated onshore-offshore gradients and how
they change through time, whereas little is known about how these ecological gradients vary
spatially within and between depositional basins. For example, the temporal stability of biofacies
gradients in the Middle Devonian Hamilton Group of New York state has been studied
extensively using both qualitative and quantitative methodologies, yet no studies have been
conducted in other regions of the Appalachian Basin to assess the spatial variability of these
gradients. Field collection from an extensive outcrop of Mahantango Formation (Hamilton
Group) in Huntingdon, Pennsylvania was conducted to characterize ecological gradients and to
identify biofacies. Cluster analysis and detrended correspondence analysis reveal seven biofacies
in the Hamilton Group of Central Pennsylvania that are distributed primarily by factors associated
with water depth. Four biofacies identified in Pennsylvania (Tropidoleptus, Tropidoleptus-
Devonochonetes, Devonochonetes, Ambocoelia) are qualitatively similar to biofacies identified in
New York. Three novel biofacies have been identified in Pennsylvania (Pustulatia-Longispina,
Rhipidomella, Rhipidomella-Devonochonetes), suggesting that additional undiscovered biofacies may exist in this basin. Quantitative comparison between Pennsylvania and New York study sites reveal that biofacies distribution throughout the Appalachian basin is governed by environmental differences associated with distance from the delta front, such as turbidity, sediment flux, or nutrient supply. For taxa shared between Pennsylvania and New York preferred environment (PE) is strongly correlated between study sites, while environmental tolerance and peak abundance are only weakly correlated.
iii TABLE OF CONTENTS
List of Tables...... v List of Figures...... vi
Chapter 1. INTRODUCTION...... 1
Chapter 2. GEOLOGIC SETTING…………………………………………...……………………3
Chapter 3. METHODOLOGY……………………………………………………………………10 Section Measurement and Correlation…………………………………………………...10 Field Collection…………………………………………………………………..………11 Quantitative Analysis…………………………………………………………………….12 Gradient Comparison with Middle Devonian of New York……………………………..14 Analysis of Niche Parameters…………………………………………………………...15
Chapter 4. RESULTS……………………………………………………………………………..18 Facies Analysis…………………………………………………………………………...18 Vertical Facies Succession……………………………………………………………….29 Sequence Stratigraphy………………………………………………………………...... 31 Cluster Analysis Results………………………………………………………………....32 Q-Mode Cluster Results…………………………………………………………32 R-Mode Cluster Results…………………………………………………………36 Cluster Analysis Summary…………………………………………………...….37 Ordination Results……………………………………………………………………….38 DCA Axis 1 Sample Scores……………………………………………………..38 DCA Axis 2 Sample Scores……………………………………………………..41
Chapter 5. DISCUSSION………………………………………………………………………...44 I. a. Biofacies Gradients…....…………….……………………………………………...44 I. b. Ecology of Biofacies..………………………………………………………………46 I. c. Oxygenation and Stratification of the Appalachian Basin………………………….48 II. Qualitative Comparison of Pennsylvania and New York Biofacies…………………..50 III. Quantitative Comparison of Pennsylvania and New York Biofacies..……………....54
Chapter 6. CONCLUSIONS……………………………………………………………………...65
References………………………………………………………………………………………...67
Appendix A: Latitude and Longitude Data……………………………………………………….73
Appendix B: Raw API Gamma Ray Data………………………………………………………...74
Appendix C: Biofacies Composition and Life History Traits…………………………………….76
Appendix D: Collection-based Rarefaction Analysis…………………………………………….81
Appendix E: Raw Data Matrix of Collection…………………………………………………….82
iv LIST OF TABLES
Table 1...... 16
Differences between Pennsylvania data set and New York data set
Table 2……………………………………………………………………………………20
Summary table of four facies identified in the Mahantango Formation in
Huntingdon County, Pennsylvania, USA
Table 3…………………………………………………………………………………....57
Overall Hamilton Group generic diversity differences between central
Pennsylvania and New York State
Table 4……………………………………………………………………………………62
Genera list for Huntingdon, Pennsylvania and New York State
v LIST OF FIGURES
Figure 1……………………………………………………………………………………4 Paleogeography of Laurentia during the Middle Devonian period
Figure 2…………………………………………………………………………………....5 Correlation table of the Middle Devonian Hamilton Group showing relationship between New York units and Pennsylvania units
Figure 3…………………………………………………………………………………....8 Proposed paleogeography of the Mahantango delta complex in central Pennsylvania, USA
Figure 4…………………………………………………………………………………..19 Measured stratigraphic section of the Mahantango Formation in Huntingdon County, Pennsylvania, USA
Figure 5…………………………………………………………………………………..21 Silty Sandstone facies of the Middle Devonian Hamilton Group in Huntingdon County, Pennsylvania, USA
Figure 6…………………………………………………………………………………..22 Zoophycos traces within the Silty Sandstone facies of the Donation Member at Huntingdon
Figure 7…………………………………………………………………………………..24 Sandy Siltstone facies of the Middle Devonian Hamilton Group in Huntingdon County, Pennsylvania, USA
Figure 8…………………………………………………………………………………..26 Silty Mudstone facies of the Middle Devonian Hamilton Group in Huntingdon County, Pennsylvania, USA
Figure 9………………………………………………………………………………...... 28 Calcareous Silty Mudstone facies of the Middle Devonian Hamilton Group in Huntingdon County, Pennsylvania, USA
Figure 10…..……………………………………………………………………………..30 Dip-oriented cross-section correlation of the Mahantango Formation in central Pennsylvania
Figure 11…………………………………………………………………………………33 Two-Way Cluster Analysis of Q-Mode (sample) clusters and R-Mode (species) clusters
vi Figure 12…………………………………………………………………………………39 Q-Mode DCA Axis 1 vs. Axis 2 scores
Figure 13…………………………………………………………………………………43 Q-Mode DCA Axis 1 score plotted against stratigraphic height of the measured section in Huntingdon
Figure 14…………………………………………………………………………………52 Distribution of Middle Devonian Hamilton biofacies in New York and Pennsylvania along a bathymetric gradient
Figure 15…………………………………………………………………………………55 DCA Analysis comparing Pennsylvania samples with New York samples
Figure 16…………………………………………………………………………………59 DCA Analysis showing shared onshore-offshore gradient between the Pennsylvania samples and New York samples
Figure 17…………………………………………………………………………………61 Correlation of preferred environment (PE), environmental tolerance (ET), and peak abundance (PA) for all shared taxa between Pennsylvania and New York State
vii INTRODUCTION
Understanding the spatial and temporal variability in the distribution of fossils is essential for investigating ecosystem change through time (Brett and Baird, 1995;
Patzkowsky and Holland, 1999; Holland and Patzkowsky, 2007), patterns of origination and extinction (Sepkoski and Miller, 1985; Sepkoski, 1987; Patzkowsky and Holland,
1997), and partitioning of diversity among local, regional, and continental scales
(Valentine and Moores, 1970; Sepkoski, 1988; Patzkowsky and Holland, 2007). One approach to characterizing the distribution of fossil taxa is to quantify ecological gradients and the occurrence and abundance of individual taxa along the gradient. For example, based on detrended correspondence analysis of two Ordovician data sets of different age, Holland and Patzkowsky (2004) compared the preferred environment (PE), environmental tolerance (ET), and peak abundance (PA) for the shared taxa. Both PE and PA were generally similar for the two data sets suggesting little change in these aspects of distribution however ET was not similar suggesting change in this niche parameter. This same approach can be used to study the spatial change in ecological gradients, although no studies have attempted this kind of comparison.
The Middle Devonian Hamilton Group in New York state is an ideal geologic setting to examine because of its purported paleoecological stability and the wealth of paleoecological data. Despite the plethora of paleoecological studies conducted in the
Hamilton Group of New York state, both qualitative (Brett et al., 1986; Savarese et al.,
1986; Vogel et al., 1987; Brower and Nye, 1991; McCollum, 1991; Brett and Baird,
1995) and recently quantitative (Bonuso, 2001; Bonuso et al., 2002a,b; Sessa, 2003;
Zambito et al., 2008; Bonelli et al., 2006), no paleoecological studies have been
1 conducted in the Hamilton Group elsewhere in the Appalachian Basin. In the 1960’s,
Ellison (1963, 1965) investigated the paleontology of the middle-late Hamilton Group in
Pennsylvania. These studies amassed relative abundance data for several outcrops throughout the Mahantango Formation in central Pennsylvania; however no quantitative assessments, specifically identifying biofacies, taxon niche parameters, and/or ecological gradients for the Mahantango Formation have ever been conducted. Additionally, with the revelation of sequence stratigraphy since Ellison’s work was conducted (Vail et al.,
1977, 1991), a re-examination of the distribution of the Pennsylvania Hamilton Group fauna within a sequence stratigraphic framework is necessary.
The goals of this study are twofold: first, to identify biofacies and develop an ecological gradient structure for the distribution of biofacies for the Hamilton Group of
Pennsylvania; and second, to compare the biofacies gradient and niche parameters observed in Pennsylvania to those of New York state to characterize similarities and differences in the distribution of biofacies over a large geographic region.
2 GEOLOGIC SETTING
During the Middle Devonian Givetian stage, approximately 385 million years ago, the paleocontinent of Laurentia was situated within the southern subtropics, spanning a large geographic range from the equator to 30º south paleolatitude, with New
York and Pennsylvania located at approximately 30º south latitude (Figure 1) (Blakey,
2011; Scotese and McKerrow, 1990; Kaufmann 2006). The Appalachian foreland basin was created as a result of crustal loading and subsequent erosion of the uplifted highlands associated with the Acadian Orogeny, where Laurentia collided with Baltica (Ettensohn,
1985). Sediments were shed into the foreland basin from the east, creating the Catskill
Wedge Delta Complex. The Hamilton Group is the oldest sedimentary package within the
Catskill Wedge Delta Complex, and was deposited approximately 388 – 383 mya
(Kaufmann, 2006). The Hamilton Group contains a range of lithologies in Pennsylvania, from the distal black shales of the Marcellus Formation through more proximal, siltstone and sandstone deposits of the Mahantango Formation.
Much work has been done to understand the depositional history and correlation of Hamilton Group strata in New York State (Brett and Baird, 1985, 1986, 1996), however correlations between the Hamilton Group in New York and Pennsylvania have been limited, especially with regard to the Mahantango Formation (Figure 2). The
Mahantango Formation spans the Giv-1 through Giv-4 third-order sequences of ver
Straeten (2007), although correlation of individual units within those intervals between
New York and Pennsylvania has not been attempted, with the exception of a correlation between two regionally distinct coral beds (Bonelli et al., 2006). The base of the
Hamilton Group in New York and Pennsylvania is the Purcell member of the
3 FIGURE 1. Paleogeography of Laurentia during the Middle Devonian period
(approximately 385 Ma). Location of the Appalachian Basin indicated by arrow.
Modified from Blakey, 2011.
4 FIGURE 2. Correlation table of Middle Devonian Hamilton Group showing relationship between New York units and Pennsylvania units. Pennsylvania units are arranged West
(left) to East (right).
5 Marcellus Formation, equivalent to the Bakoven, Cherry Valley, Hurley, and Stony
Hollow members in New York (ver Straeten and Brett, 2006; Kohl et al., in press). The termination of Hamilton Group deposition in both New York and Pennsylvania is the widespread Taghanic unconformity within the Giv-4 interval dated at 360.7 ± 2.7 Ma
(Kaufmann, 2006). Therefore, although individual correlation of members within the
Hamilton Group between New York and Pennsylvania is difficult, it is possible to constrain the study interval within these two timelines.
The Mahantango Formation of Pennsylvania is equivalent to the Skaneatles,
Ludlowville, and Moscow Formations of New York, although these units differ lithologically. The Skaneatles, Ludlowville, and Moscow Formations are composed of homogeneous mudstones with sparse sedimentary structures and thin limestones
(Savarese et al., 1986). The Skaneatles Formation differs from the Ludlowville and
Moscow formations in that it is mainly composed of dark gray to black sparsely fossiliferous shales, while the younger Ludlowville and Moscow formations contain fossiliferous gray mudstones and thin calcareous limestones. The lithologies present in much of New York State during the Hamilton Interval suggest that the deposition occurred along a low-angle, gentle basin slope grading to shallower environments near the sediment source in the eastern Finger Lakes region of New York (Brett, Baird, and
Miller, 1986; Savarese et al., 1986; Brett et al., 2007). In comparison, the Mahantango
Formation of Pennsylvania is more influenced by siliciclastic deposition and sediment input because of the proximity to the prograding Mahantango delta complex in central
Pennsylvania (Kaiser, 1972; Prave et al., 1996).
6 The prograding Mahantango delta complex was initiated by sediments shed from the eastern terrestrial highland region into the Appalachian foreland basin along a NE-SW trending paleoshoreline (Kaiser, 1972; Prave et al., 1996). The morphology of the
Mahantango delta has been debated with evidence in support of a fluvially-dominated delta (Ellison, 1965; Faill et al., 1978), storm-dominated prograding delta (Goldring and
Bridges, 1978), and most recently progradation of a tidally-influenced delta complex over offshore, pelagic muds (Prave et al., 1996) with the sediment source in modern south- central Pennsylvania, near Harrisburg (Figure 3). Progradation of the Mahantango delta complex results in stratigraphy characterized by coarsening-upward parasequences.
The Mahantango Formation thus has more siliciclastic components in
Pennsylvania than New York, while the Skaneatles, Ludlowville, and Moscow
Formations are more carbonate-rich. For example, shallowing-upward parasequences within the Mahantango Formation of Pennsylvania are capped by coarse siltstones and sandstones, while shallowing-upward parasequences in New York units are capped by limestone beds.
In addition to the differences in Hamilton Group sedimentology between New
York and Pennsylvania, the sedimentology of the Mahantango Formation throughout
Pennsylvania is also variable depending upon proximity to the Mahantango delta complex near present-day Harrisburg, PA. Although the lithology of the Mahantango
Formation may be different from locality to locality, all Mahantango intervals in
Pennsylvania are variations on a tripartite lithologic theme. The lowest unit consists of fine-grained silty shales and mudstones across central Pennsylvania. The middle unit is characterized by a thick succession of coarse-grained siltstones and sandstones near the
7 FIGURE 3. Proposed paleogeography of the Mahantango delta complex in central
Pennsylvania, USA. Note the west-northwest progradation of coarser grained sediments from the mouth of the Mahantango Delta near Harrisburg, PA (dotted pattern) over fine- grained pelagic muds in the distal region of the Appalachian Basin (no pattern). Study site located in Huntingdon, Huntingdon County, Pennsylvania, USA. Modified from
Prave et al., 1996.
8 delta mouth (locally named the Montebello member) and a combination of shales, siltstones, and sandstones further west. The upper unit exhibits a return to fine-grained silty shales and mudstones (Figure 2). Localities near the sediment source of present-day
Harrisburg contain the coarsest-grained units, with up to ten individual coarsening- upwards parasequences reported for the Montebello member of the Mahantango
Formation at the most proximal sites (Kaiser, 1972; Prave et al., 1996). In contrast, the most distal localities are finer-grained and contain as few as two coarsening-upwards parasequences within the middle member.
The Mahantango Formation in Huntingdon County, Pennsylvania is composed of five lithologically distinct members, in order from oldest to youngest: Gander Run,
Backbone Ridge, Crooked Creek, Donation, and Frame Members (Figure 2). The Gander
Run Member is an olive-gray claystone and shale, which stands in stark contrast with the black, anoxic Marcellus Formation below. The Backbone Ridge Member is an argillaceous medium to dark grayish-red siltstone or silty claystone containing small (10 cm thick) beds of calcareous siltstone. The Backbone Ridge siltstone is sharply overlain by the silty shale of the Crooked Creek Member. The Crooked Creek Member is composed of medium-gray claystone and shale with concretions common in the upper half of the interval. The Donation Member is a calcareous siltstone which becomes increasingly argillaceous towards the top. The final member of the Mahantango
Formation in Huntingdon is the Frame Member. The Frame Member is composed of medium-gray claystone with concretions of fossiliferous, silty limestone in the upper half of the interval. Above the Hamilton Group is the conspicuous Tully Limestone, which provides a convenient marker bed for correlation between Pennsylvania and New York.
9 METHODOLOGY
Section Measurement and Correlation
A measured stratigraphic section was completed at decimeter-scale resolution for the Mahantango section exposed along Route 22 in Huntingdon County, Pennsylvania,
USA. The Gander Run Member was found to be unfossiliferous in the exposed section and will not be considered further in this study. The locations of each of these outcrops are described with latitude and longitude measurements in Appendix A.
Lithologic facies were interpreted by synthesizing lithology, mineralogy, grain size distributions, and level of bioturbation. Bioturbation was scaled between 0 and 6, with a value of 0 indicating no bioturbation and 6 fully bioturbated (Droser and Bottjer,
1986). Important sequence stratigraphic surfaces including marine flooding surfaces and sequence boundaries were noted where observable in the field.
Spectral gamma ray data (Th, K, U) was obtained at regular 10 cm – 30 cm intervals along the Mahantango outcrop, dependent upon how uniform the lithology of the section was (see Appendix B for gamma ray measurements). Spectral gamma ray data were totaled, converted to API units, and imported into PETRA software for correlation with other Mahantango sections in Central Pennsylvania to place the Huntingdon outcrop in a larger, basin-scale geographic context. Correlations among sections were based on marine flooding surfaces, sequence boundaries, and coarsening/fining upward parasequences. Correlation among Mahantango sections also revealed coarsening/fining upward parasequences and important boundaries that may not be exposed along the measured outcrop section.
10 Field Collection
Fossil samples were obtained where lithology and weathering intensity permitted collection. Each sample consisted of enough fossiliferous rock to fill a 1-gallon freezer bag if possible, otherwise abundance counts were tallied in the field where lithology
(Donation Member) did not allow for easy removal and transportation. Multiple samples from the same stratigraphic horizon were collected to create replicate samples deposited during the same time, and to prevent biases attributed to spatial heterogeneity or patchiness (Zambito et al., 2008). Samples were brought back to the laboratory for preparation and identification. Lab preparation of samples consisted of washing and scrubbing each sample with warm water. Specimens were identified using a Wild M3Z light microscope. Genus and species level identification followed Linsley (1994) and
Ellison (1965).
Individuals were identified to the genus level, however a large number of genera are monospecific, permitting identification to species level. A minimum number of individuals approach was used to tabulate abundance data (Patzkowsky, 1995;
Patzkowsky and Holland, 1999). The abundance of brachiopods and bivalves was calculated as the total number of articulated specimens plus one half of the number of single valves. The minimum abundance of trilobites was considered the largest total of either the cranidia or pygidia. Crinoid columnals and bryozoans are subject to disarticulation, which complicates absolute abundance counts for these taxa.
Consequently, these taxa were included in this study as qualitative presence-absence data only. The total data set comprises 64 taxa collected from 78 assemblages, representing
4,822 individuals (see Appendix E for raw data matrix of species and samples).
11 Quantitative Analysis
Two-way cluster analysis was performed using R statistical software (v. 2.10.1, download available at http://www.r-project.org) and used to produce clusters of samples with similar faunal composition (Q-Mode analysis) and clusters of taxa that tend to co- occur (R-Mode analysis).
Several data standardizations were performed on both the Q-Mode and R-Mode data matrices to reduce variability within the data set. First, outliers were removed from both the Q-Mode and R-Mode data sets. Samples were culled for low diversity assemblages by removing any samples composed of only one taxon. Additionally, taxa occurring in less than 5% of the total number of assemblages were considered rare and removed from R-Mode analysis (Holland and Patzkowsky, 2004; Brett et al., 2007).
Upon removing outliers, the final data set contained 40 taxa and 77 assemblages.
For both Q-Mode and R-Mode analysis, transformation of the culled data set was conducted by dividing the abundance of each taxon in a sample by the total individuals collected within that sample. This transformation was performed to reduce the effect of sample size on the data set. For R-Mode analysis, each taxon’s abundance was divided by its maximum abundance value to adjust for large differences in the abundances of taxa, so that groups of taxa cluster based more on co-occurrence of taxa than by dominance of a single taxon.
Cluster analysis was performed using the Ward’s linkage method, which
“minimizes increases in the sum of squares distances from each individual to the centroid of its group” (McCune and Grace, 2002). The distance matrix was calculated using the
12 Bray-Curtis method, a city-block distance metric. R-Mode analysis uses the same distance approach to calculate the distance between taxa in all samples.
Biofacies were then defined by comparing the Q-Mode clustering of samples with the R-Mode clustering of taxa. This approach, two-way cluster analysis, allows biofacies to be recognized as groups of samples that share similar taxonomic associations.
Additionally, two-way cluster analysis is a useful way to characterize biofacies because relative abundances of each taxon in each sample can be displayed, which allows for easy recognition of dominant taxa in each biofacies. Taxa often occur across several biofacies, indicating that biofacies are not discrete entities, but rather characterize abundances of taxa along an ecological or environmental gradient.
Guild membership of each biofacies was compiled from a summary of life habit traits of the taxa within each biofacies cluster using the paleoecological information for each taxon in the Paleobiology Database (http://www.pdbd.org). Guild membership follows the categories of Brower and Nye (1991) and Bonuso et al. (2002a,b), which also assessed guild membership within the Hamilton Group. Ecologic metrics were also calculated to further characterize each biofacies cluster, including Simpson’s index of diversity (D), species richness (R), Shannon’s H, and Buzas and Gibson’s E (Hayek and
Buzas, 1997). Additionally, sample-based rarefaction was conducted using R statistical software to compare diversity between biofacies (Appendix IV).
Multivariate ordinations were conducted to explore how biofacies are arrayed along ecological/environmental gradients. This approach is useful in understanding which environmental variables are governing the overall species distribution. An ordination of this data set was conducted using detrended correspondence analysis (DCA) using R
13 statistical software. DCA is a widely used ordination technique in quantitative paleoecological studies and is useful in linking stratigraphic and paleobiological interpretation (Scarponi and Kowalewski, 2004). Like Cluster Analysis, DCA ordination was also conducted on a data set subject to the same transformations outlined above.
Gradient Comparison with Middle Devonian of New York
While qualitative comparisons between paleoecological data sets are informative in a rudimentary sense, these comparisons provide no quantitative assessment of the similarity or differences between data sets. Quantitative comparisons between paleoecological data sets are much more informative than qualitative comparisons because they assess the degree of similarity/dissimilarity in a quantitative and often statistical manner.
Unfortunately, there is a paucity of quantitative paleoecological data available in the literature for the Middle Devonian, primarily limited to the most recent paleontological studies conducted within the last three decades. Additionally, where quantitative data sets are available, there may be distinct differences between the data sets that potentially bias the reliability of quantitative comparisons. These differences include
(but are not limited to) lithology, sequence stratigraphy, sampling methodology, geographic area, characterization of abundance, taxonomic resolution, and species identification. Furthermore, in order to make quantitative comparisons between data sets, the abundance count data and environmental data must be easily and readily accessible to other researchers – a problem that is pervasive in the currently available paleoecological literature.
14 The Middle Devonian data set of Savarese et al. (1986) was found to contain the best detailed collection and environmental data for use in quantitative comparisons because of the availability of absolute abundance data and well-constrained environmental information. Table 1 details the similarities and differences between these data sets from the Hamilton Group interval.
DCA analysis of the Savarese et al. data set was conducted using the same data transformations as the DCA analysis of the Huntingdon data set (rare taxa removed, depauperate samples culled, and standardization by dividing through by row totals). This ensured that any existing differences between the two data set ordinations were ecological, and not the result of methodological differences while producing the DCA.
The analyzed data set of Savarese et al. (1986) consists of 23 samples with 40 taxa.
Analysis of Niche Parameters
The calculation of niche parameters for taxa shared between Pennsylvania and
New York is another way to compare gradient structure between the two areas. Each shared taxon’s niche was modeled using DCA sample scores to form a Gaussian species response curve, following the methodology developed by Holland and others (Holland et al., 2001; Holland and Patzkowsky, 2004; Holland and Zaffos, 2011, Patzkowsky and
Holland, 2012). Preferred environment (PE) was calculated as the DCA axis 1 sample score for a given taxon. Environmental tolerance (ET) was calculated as the standard deviation of all DCA axis 1 sample scores including the given taxon. Peak abundance
(PA) was calculated as the percentage of all samples that contain the given
15 TABLE 1. Differences and Similarities between Huntingdon, Pennsylvania data set (this study) and New York State data set (Savarese et al., 1986).
This Study Savarese et al. (1986)
Huntingdon County, PA Livingston County, NY Study Area
Mahantango Frm. Ludlowville Frm.
Interval (Giv. 1 – Giv. 4) (Giv. 2)
Claystone and Silty Sandstone to Silty Mudstone Lithology Argillaceous Limestone
77 23 Total Samples
39 40 Total Taxa*
Absolute Abundance Absolute Abundance Abundance Data?
Raw Data Data Matrix in Appendix Data Matrix in Text
Presented?
* Culled for taxa occurring in <5% of samples
16 taxon falling within one standard deviation (ET) of the taxon’s PE. These niche metrics were calculated for each shared taxon using sample scores from the Pennsylvania DCA and the New York DCA. The value of each taxon’s niche metric was plotted to produce a correlation of the niche metric with all shared taxa. Niche metrics with Spearman rank correlations greater than a value of 0.5 were considered to be conserved between study sites after Holland and Zaffos (2011), while those with correlations less than 0.5 were considered to be altered at the basin-wide geographic scale.
17 RESULTS
I. Facies Analysis
Four facies were identified in the Mahantango Formation in Huntingdon County, based on grain size, mineralogy, bedding thickness, sedimentary structures, and degree of bioturbation. Figure 4 shows the location of each facies and the vertical relationship of facies to one another throughout the measured lithologic section. Table 2 contains a summary of lithologic characteristics and the environmental interpretation of each facies described below.
I.a.i. Silty Sandstone Facies Description
The Silty Sandstone facies is composed of massive coarsening-upward, very fine lower (vfL) to very fine upper (vfU), 10-meter thick silty sandstone (Figure 5). Plane parallel laminations (PPL) are present up to 2 meters from the basal contact of this facies.
Fossils become increasingly abundant upward, many of which are abraded. Bioturbation is abundant in higher horizons within this facies (bioturbation index = 6), with Zoophycos traces common (Figure 6).
18 19 TABLE 2. Summary table of four facies identified in the Mahantango formation in
Huntingdon County, Pennsylvania, USA.
Facies Observations Interpretation Silty Sandstone vfL to vfU coarsening upwards Lower shoreface, slightly below amalgamated sandstone. PPL present. or at FWB Zoophycos traces common.
Sandy Siltstone Sandy siltstone with vfL sand lenses Proximal offshore marine, above interbedded. Sand lenses pinch and swell SWB below FWB. Storm and laterally. HCS present in sands. Sand beds hemipelagic deposits. thicken upwards. Sand beds cemented with calcite. Planolites and Chondrites burrows.
Silty Mudstone Silty mudstone/claystone dominant. Thin Distal offshore marine below silty to vfL sand beds interbedded with SWB. Storm and hemipelagic claystone and increasingly apparent deposits. More distal than Sandy towards top. Siderite nodules present. Siltstone facies.
Calcareous Silty Silty claystone and shale with silty Distal offshore marine below Mudstone limestone common towards top. SWB. Similar depth to Silty Fossiliferous limestone concretions present. Mudstone facies. Pyrite nodules present in silty lime layers.
20 FIGURE 5. Silty Sandstone facies of the Middle Devonian Hamilton Group in
Huntingdon County, Pennsylvania, USA. This facies is characterized by vfL to very fine upper (vfU) amalgamated sandstone. Photograph taken within the Donation Member at meter 160 in measured section.
21 FIGURE 6. Zoophycos traces within the Silty Sandstone facies of the Donation Member in Huntingdon County, Pennsylvania, USA. Zoophycos traces are commonly found within the top 2 meters of the Donation Member. Photograph taken at approximately meter 162 in measured section.
22 I.a.ii. Silty Sandstone Facies Interpretation
The Silty Sandstone facies was deposited in a lower shoreface setting (Prave et al., 1996). This facies contains the coarsest grain size throughout the Huntingdon section and therefore represents the most proximal environment in this study. Though sedimentary structures like cross-bedding and ripplemarks might otherwise be visible within this facies, these sedimentary structures have been disrupted and amalgamated by intense burrowing and thus are not preserved within this facies.
I.b.i. Sandy Siltstone Facies Description
The Sandy Siltstone facies is dominated by decimeter to meter thick sandy siltstones interbedded with 2-5 cm thick very fine lower (vfL) sand lenses (Figure 7).
These vfL sand lenses are not continuous, but rather pinch and swell laterally. These vfL sands thicken and coarsen to very fine upper sand (vfU) higher in section. Sand lenses are cemented with calcite. Hummocky Cross-stratification (HCS) is also present within the sand lenses. Planolites and Chondrites burrows are found within vfU sands. Bioturbation is high within the siltstone (bioturbation index = 4-5), often preventing sharp bedding planes from being observed between the siltstone beds.
I.b.ii. Sandy Siltstone Facies Interpretation
The depositional environment of the Sandy Siltstone facies is an offshore marine setting, evidenced by the abundance of marine body and trace fossils and silty grain size
(Prave et al., 1996). The sandy siltstone beds were likely deposited under normal, fair- weather conditions at a depth above storm wave base (SWB) but below fair-weather
23 10 cm
FIGURE 7. Sandy Siltstone facies of the Middle Devonian Hamilton Group in
Huntingdon County, Pennsylvania, USA. This facies is characterized by sandy siltstone beds interbedded with 2-5 cm very fine lower sand lenses. Photograph taken within the
Donation Member at meter 139 in measured section. Scale bar in top left of photo is 10 cm.
24 wave base (FWB). The thin vfL to vfU sand beds were likely deposited during high energy storm events because of their sharp contacts with underlying finer-grained siltstone beds and internal fining upwards within each 2-5 cm sand bed (Prave et al.,
1996).
I.c.i. Silty Mudstone Facies Description
The Silty Mudstone facies is dominated by silty mudstone and claystone interbedded10 cm with approximately 0.5 meter-thick silty to vfL sand beds (Figure 8). Silty mudstones commonly exhibit cleavage and bedding is often disrupted. Additionally, bedding is very difficult to observe within the mudstone and claystone owing to the intense degree of bioturbation within this lithology (bioturbation index = 6). Centimeter- scale siderite nodules are present within this facies.
I.c.ii. Silty Mudstone Facies Interpretation
Similar to the Sandy Siltstone facies, the depositional environment of the Silty
Mudstone facies is offshore marine, near or just below SWB. This facies, however, is much more dominated by fine grained muds and clays, with less frequent storm- generated sand beds relative to the Sandy Siltstone facies. This would suggest that the
Silty Mudstone facies is farther from the sediment source in a more distal offshore environmental setting.
25 FIGURE 8. Silty Mudstone facies of the Middle Devonian Hamilton Group in
Huntingdon County, Pennsylvania, USA. This facies is characterized by silty mudstone and claystone interbedded with thin silty to very fine lower sand bodies. Photograph taken within the Frame member at meter 240 in measured section.
26 I.d.i. Calcareous Silty Mudstone Facies Description
The Calcareous Silty Mudstone facies is dominated by silty claystone and shale with silty limestone horizons also present higher in stratigraphic section (Figure 9). Large decimeter-scale fossiliferous limestone concretions are present in this facies. Pyrite nodules are commonly found in silty limestone horizons. Bioturbation is high, with bedding being overprinted by burrowing organisms (bioturbation index = 6).
I.d.ii. Calcareous Silty Mudstone Facies Interpretation
Similar to the Silty Mudstone facies, the environmental interpretation of the
Calcareous Silty Mudstone facies is distal offshore marine at or below SWB evidenced by the dominance of fine-grained claystone and silty limestone. This facies was likely deposited under relatively calmer conditions with less sediment input than the Silty
Mudstone facies. This facies, along with the Silty Mudstone facies, represent the deepest, most distal depositional environment in this study.
27 FIGURE 9. Calcareous Silty Mudstone facies of the Middle Devonian Hamilton Group in Huntingdon County, Pennsylvania, USA. This facies is characterized by silty claystone and shale with silty limestone horizons and concretions. Blocky cleavage is unique to the
Calcareous Silty Mudstone facies and only observed within this facies at Huntingdon.
Photograph taken within the upper Frame member at meter 252 in measured section.
28 II. Vertical Facies Succession
The vertical facies succession of the measured stratigraphic section in Figure 4 defines the depositional history for the Mahantango Formation at this outcrop.
The Mahantango interval begins above the Purcell Member in Figure 4 and is characterized by the distal offshore deposits of the Silty Mudstone facies. This Silty
Mudstone facies (Gander Run Member) gradually transitions conformably into the Sandy
Siltstone facies of the Backbone Ridge Member at approximately 140 meters in measured section. The Sandy Siltstone facies of the Backbone Ridge Member is abruptly overlain with the Silty Mudstone facies of the Crooked Creek Member, indicating that the base of the Crooked Creek is a marine flooding surface. A third-order coarsening-upward parasequence is thus identified here: the Silty Mudstone facies of the Gander Run
Member coarsens upwards through the Sandy Siltstone facies of the Backbone Ridge
Member and is terminated with the marine flooding surface indicating transgression and deposition of the offshore, Silty Mudstone facies of the Crooked Creek Member.
The upper contact between the Silty Mudstone facies of the Crooked Creek
Member and the Sandy Siltstone just below the Silty Sandstone facies of the Donation
Member is covered locally, inhibiting interpretation of whether there is a conformable or unconformable transition between these facies. The Sandy Siltstone facies gradually coarsens and thickens upwards into the Silty Sandstone facies of the Donation Member at this locality. The transition between the Sandy Siltstone facies of the Donation Member and the Silty Mudstone facies of the Frame Member is also covered locally; however correlation among sections (Figure 10) suggests that there is an unconformable transition between these facies marked by a marine flooding surface. Figure 10 shows that there is a
29 FIGURE 10. Dip-oriented cross-section correlation of the Mahantango Formation in central Pennsylvania. Gamma Ray values are plotted in the left three tracks, while outcrop measured section was used for correlation in the remaining sections. Sections shown are oriented in a west – east direction from left – right respectively. The datum used for correlation is the MFS2 marine flooding surface of the Mahantango Formation, with other correlations including the widespread Purcell Member Sandstone recording widespread base level fall in the Marcellus Formation, widespread base level rise within the Crooked Creek member (MFS1), and the base of the dark black, anoxic Burkett Shale marking the end of Hamilton deposition (BURKETT).
30 second conformable, coarsening-upwards parasequence at this outcrop, starting with the
Silty Mudstone of the Crooked Creek shale coarsening upwards to the Sandy Siltstone of the Donation member and terminated with the marine flooding surface before deposition of the offshore Silty Mudstone facies.
The Silty Mudstone facies of the Frame Shale Member transitions upward into the
Calcareous Silty Mudstone facies, suggesting that there is either a decrease in sediment input during this time or that the depositional environment was relatively deeper/more distal than when conditions favored deposition of the Silty Mudstone facies. The
Calcareous Silty Mudstone facies is unconformably overlain by the Tully limestone, and concludes deposition of the Mahantango Formation in Huntingdon, PA.
III. Sequence Stratigraphy
The measured stratigraphic section of the Mahantango Formation in Huntingdon,
PA was correlated with several additional wells and outcrop studies to reveal its placement in a larger geographic and sequence stratigraphic context (Figure 10).
Correlation is based on a dip-oriented cross-section of the Mahantango Formation throughout central Pennsylvania, with western distal localities on the left and eastern proximal localities on the right. This correlation was based on the MFS2, which marked a widespread base-level rise that is traceable throughout central Pennsylvania. The lower limit of the correlation is the widespread and clearly identifiable Purcell Member of the
Marcellus Formation, however it is only seen in the western well log data and in outcrop at Huntingdon. Because of this, the Purcell timeline was not able to be used for widespread correlation, even though this sand body would provide the best correlatable
31 datum. The upper limit of the correlation is the widespread base-level rise that marks the termination of Mahantango deposition and deposition of the deep black, anoxic Burkett
Formation.
This correlation reveals that the covered intervals at the Huntingdon outcrop do not contain any significant sequence boundaries or maximum flooding surfaces, suggesting that the entirety of the Mahantango section in Huntingdon, Pennsylvania consists of two to four coarsening upward parasequences (Figure 4). These parasequences are not able to be correlated in a one-to-one fashion in the more proximal deposits because the number of coarsening upward parasequences varies greatly from west to east
(Kaiser, 1972; Prave et al., 1996). For example, there are two observable coarsening upwards cycles in the distal deposits at Huntingdon, PA, while there are upwards of ten coarsening upwards cycles observed near Harrisburg, PA (Kaiser, 1972). The greater number of cycles observed near Harrisburg is probably a result of delta switching near the delta mouth and sediment source. Thus, correlation of individual cycles between
MFS1 and MFS2 in Figure 10 is not possible because they are not eustatically driven, but rather localized depositional events.
Cluster Analysis Results
Q-Mode Cluster Results
Q-Mode cluster analysis reveals seven clusters defined by their similarity in taxonomic composition (Figure 11, Appendix III). Cluster A comprises the diverse
Devonochonetes biofacies. This cluster is dominated by the chonetid brachiopod
32 FIGURE 11. Two-Way Cluster Analysis of Q-Mode (sample) clusters (top) and R-Mode
(species) clusters (right). Relative abundance of each species in each sample is represented by a circle of varying diameter. Seven biofacies are color coded in this figure: red – Tropidoleptus, blue – Ambocoelia, purple – Pustulatia-Longispina, aqua –
Tropidoleptus-Devonochonetes, orange – Rhipidomella-Devonochonetes, green –
Rhipidomella, and gray – Devonochonetes.
33 Devonochonetes (46.6% of total abundance) with additional important taxa including the
spiriferid brachiopod Mucrospirifer (21.2%), and the bivalve genera Nuculites (9.5%) and
Paleoneilo (4.0%). This cluster contains the highest relative abundance of bivalves
throughout the study interval. Taxa of lesser abundance span nearly all marine
invertebrate groups, including trilobites (Phacops), gastropods (Bembexia), cephalopods
(Striacoceras, Spyroceras), bryozoans (Taeniopora, Fenestella, Sulcoretepora), and
crinoids. Cluster A is composed of samples from the distal offshore Silty Mudstone and
Calcareous Silty Mudstone facies and contains the largest richness (median = 6 species)
when rarefied to 20 individuals.
Cluster B comprises the Rhipidomella biofacies, and is composed largely of the
orthid brachiopod Rhipidomella (83.5% of total abundance). Lesser faunal elements
include the spiriferid brachiopod Megakozlowskiella (5.3%) and abundant crinoid and
bryozoan colonies. Bivalves are rarest within this cluster, comprising less than 1% of the
relative abundance of individuals collected. Trilobites and gastropods are absent from this
cluster. Cluster B contains samples from the lower shoreface Silty Sandstone facies only
and has the lowest richness (median = 4 species) when rarefied to 20 individuals
collected.
Cluster C defines the Rhipidomella – Devonochonetes biofacies, and is dominated
by a nearly equal abundance of the orthid brachiopod Rhipidomella (17.8%), the chonetid brachiopod Devonochonetes (23.3%), and the rhynchonellid brachiopod Camarotoechia
(26.7%). Bivalves and gastropods are rare within this cluster. Crinoid columnals are also
found within this cluster. Cluster C is composed of samples from both the Silty Mudstone
and Silty Sandstone facies and exhibits intermediate richness (median = 5 species)
34 relative to the other clusters when rarefied to 20 individuals collected.
Cluster D comprises the Tropidoleptus – Devonochonetes cluster, and is
dominated by the rhynchonellid brachiopod Tropidoleptus (21.7%) and the chonetid brachiopod Devonochonetes (12.7%). This biofacies is relatively more diverse than the other biofacies, with the spiriferid brachiopods Pustulatia and Mucrospirifer, and also
contains an intermediate presence of the bivalves Nuculites, Paleoneilo, and Grammysia.
Crinoids and fenestrate bryozoans also contribute to the high richness of this cluster.
Cluster D is composed of samples from a variety of offshore facies, including the Sandy
Siltstone facies, Silty Mudstone facies, and the Calcareous Silty Mudstone facies. The
richness of this cluster is similar to that of Cluster C, with a median richness of 5 species
when rarefied to 20 individuals.
Cluster E defines the Pustulatia – Longispina biofacies and is composed of nearly
equal relative abundances of the spiriferid brachiopod Pustulatia (38.5%) and the
chonetid brachiopod Longispina (31.0%). The bivalve genus, Nucula, is also commonly
found within this faunal association with larger relative abundance than any other cluster.
The bivalve genera Nuculites and Paleoneilo are also present here, however they are extremely rare. Cluster E contains only samples from the offshore Silty Mudstone facies and exhibits similar richness (median = 5 species) to Clusters C and D.
Cluster F comprises the Ambocoelia cluster and is dominated by the spiriferid
brachiopod Ambocoelia (59.0%). Also commonly associated with this biofacies is the
spiriferid brachiopod Emanuella (10.0%) and the rhynchonellid brachiopod Leiorhynchus
(13.3%). Additionally, crinoid ossicles are present in approximately half of the collected
samples. The bivalves Nuculites, Paleoneilo, and Nucula are rare within this cluster.
35 Cluster F is composed only of samples from the offshore Calcareous Silty Mudstone
facies and exhibits a similarly low richness to that of Cluster A (median = 4 species)
when rarefied to 20 individuals.
Cluster G comprises the Tropidoleptus biofacies and is dominated by the
rhynchonellid brachiopod Tropidoleptus (69.3%), with other common faunal elements
including the spiriferid brachiopod Mucrospirifer (5.6%), the chonetid brachiopod
Devonochonetes (3.1%), and another rhynchonellid brachiopod Camarotoechia (2.1%).
The bivalves Nuculites and Paleoneilo constitute a rare portion of this cluster
(approximately 7% of the total abundance). Crinoid ossicles are present within this
biofacies, occurring in approximately half of the samples collected. Cluster G is
composed of samples from both Sandy Siltstone and Silty Mudstone facies and contains a
rarefied richness indistinguishable from that of Clusters C, D, and E (median = 5).
R-Mode Cluster Results
R-Mode cluster analysis produces 5 distinct clusters of co-occurring taxa. Cluster
I is composed of Devonochonetes, Mucrospirifer, Nuculites, and crinoid columnals. This
cluster is primarily associated with Q-Mode cluster G, but is also linked to cluster D and
E by the shared abundance of the chonetid brachiopod Devonochonetes.
Cluster II is composed of a diverse assemblage of taxa, which includes brachiopod genera Tropidoleptus, Camarotoechia, Pustulatia, and Mediospirifer, as well
as a diverse suite of bivalve genera including Paleoneilo, Nuculites, Bucanopsis, and
Grammysia. This cluster is associated with Q-Mode clusters A and D.
Cluster III is composed of five genera, which include Nucula, Longispina,
36 Leiorhynchus, Ambocoelia, and Emanuella. This cluster is associated with Q-Mode clusters B and C.
Cluster IV is composed of a diverse assemblage representing nearly all of the remaining taxa found in either proximal or distal offshore samples. This cluster is not restricted to any one particular Q-Mode cluster, but rather these taxa are rare occurrences which exist throughout all of the offshore stratigraphic horizons sampled.
Cluster V is composed of the brachiopods Rhipidomella, Megakozlowskiella,
Elita, and Protoleptostrophia, the bivalve Cornellites, and gastropods. This cluster is primarily associated with Q-Mode cluster F, but also contains taxa found within cluster E.
This cluster branches off from the other clusters at a very high level because it contains the suite of taxa found within the lower shoreface environment.
Cluster Analysis Summary
Q-Mode and R-Mode cluster analysis reveals seven biofacies associations with different preferred environments. Q-Mode clusters E and F represent the Rhipidomella-
Devonochonetes and Rhipidomella biofacies respectively, and are primarily found within the lower shoreface deposits of facies C. Clusters A, D, and G represent the
Tropidoleptus, Tropidoleptus-Devonochonetes, and Devonochonetes biofacies, which are found within both proximal and distal offshore marine environments (Sandy Siltstone facies, Silty Mudstone facies, Calcareous Silty Mudstone facies) below FWB but above
SWB. Clusters B and C represent the Ambocoelia and Pustulatia-Longispina biofacies which are restricted to the distal offshore environment, found primarily within deposits of
Silty Mudstone and Calcareous Silty Mudstone facies respectively.
37 Ordination Results
DCA Axis 1 Sample Scores
Detrended correspondence analysis (DCA) was used to ordinate samples and infer their arrangement along environmental gradients. DCA Axis 1 reflects a bathymetric gradient, with the distribution of samples in ordination space responding to one or more of the numerous factors associated with water depth (i.e. oxygen concentration, turbidity, sediment input, etc.). This DCA gradient result is similar to many other quantitative paleoecological studies which find DCA Axis 1 representing a water depth gradient
(Patzkowsky, 1995; Olszewski and Patzkowsky, 2001; Holland et al., 2001; Holland and
Patzkowsky, 2004; Scarponi and Kowalewski, 2004; Brett et al., 2007). Figure 12a plots all samples coded by facies membership determined solely by lithologic criteria. Samples with high axis 1 scores represent samples collected from lower shoreface environment
(Silty Sandstone facies) and plot on the right side of Figure 12a. Conversely, samples with low axis 1 scores represent relatively deeper samples (Silty Mudstone and
Calcareous Silty Mudstone facies) and plot on the left side of Figure 12a. The overlap of samples is important to note because it further emphasizes that samples were collected throughout a range of depositional environments and that these environments fall along a gradient, and thus are not discrete.
38 FIGURE 12. A) Q-Mode DCA axis 1 vs. axis 2 scores of 77 samples coded by facies membership. Note the upper-left trending of marly shale samples and the bottom-left trending of distal offshore samples. B) Q-Mode DCA axis 1 versus axis 2 scores of 77 samples coded by biofacies membership.
39 The DCA ordination of samples was also coded by biofacies to better understand
their distribution in the Mahantango formation (Figure 12b). Samples from the
Rhipidomella biofacies were collected in the shallowest deposits and are found within the
lower shoreface deposits of the Silty Sandstone facies. Samples from the Rhipidomella-
Devonochonetes biofacies were also found within the lower shoreface (Silty Sandstone facies) to proximal offshore (Sandy Siltstone facies) deposits and plot with relatively high
DCA axis 1 scores. Three biofacies plot with intermediate Axis 1 scores, including the
Tropidoleptus, Tropidoleptus-Devonochonetes, and Devonochonetes biofacies. The
remaining two biofacies which are found primarily within the distal offshore environment
(Pustulatia-Longispina and Ambocoelia) plot with low Axis 1 scores. There is significant
overlap between clusters which plot with intermediate and low axis 1 scores. This
underscores the notion that biofacies are not discrete, but rather contain associations of
taxa which overlap. Furthermore, these biofacies are found within deep offshore
mudstones which are lithologically very similar and may not vary much in depositional
environment.
By plotting DCA Axis 1 sample scores versus stratigraphic height, one can
observe how the sequence stratigraphic architecture exerts a strong control on the
occurrence and distribution of fossils (Figure 13). For example, abrupt shifts from high
DCA axis 1 scores to low DCA axis 1 scores correlate with parasequence boundaries
marked by marine flooding surfaces, such as at 140 meters in the section (Figure 13).
Additionally, gradual increases in DCA axis 1 scores are consistent with coarsening
upward parasequences in the measured stratigraphic section. There are several
stratigraphic intervals that were difficult to collect from due to poor exposure or the
40 interval was covered, which prevented a completely smooth record of water depth change from being resolved by the DCA scores. Nevertheless, DCA scores independently resolve important sequence stratigraphic horizons that exhibit a strong control on the distribution of biofacies (Holland, 1996). This further emphasizes the importance of having a sequence stratigraphic framework for understanding the distribution of biofacies in time and space.
DCA Axis 2 Sample Scores
DCA Axis 2 represents a temporal signal primarily reflected in the offshore samples (Figure 12a and 12b). Relatively older offshore samples from the lower Crooked
Creek Member have low DCA Axis 2 scores, while younger offshore samples from the
Frame Shale Member have higher DCA Axis 2 scores. This temporal signal has at least two explanations. First, the gradient along DCA Axis 2 could reflect environmental differences through time within the offshore environment. Samples collected from the offshore environments of both the Silty Mudstone facies and the Calcareous Silty
Mudstone facies exhibit a range from low-to-intermediate DCA axis 2 scores. These samples may separate along DCA Axis 2 because of varying carbonate content within the samples, for example the purely siliciclastic samples of the Silty Mudstone facies of the
Crooked Creek Member exhibit low DCA Axis 2 scores whereas samples of the
Calcareous Silty Mudstone facies were collected in the marly upper Frame Shale Member and exhibit high DCA Axis 2 scores. Secondly, this separation may also be the result of taxonomic turnover in the offshore environment. Furthermore, there is also a difference in taxonomic composition at these different stratigraphic horizons between the
41 Pustulatia-Longispina biofacies of the Crooked Creek member and the Ambocoelia biofacies of the upper Frame member. Because of the similarity of these depositional environments and the variation in taxonomic composition within the offshore environment, the temporal signal reflected in separation along DCA Axis 2 could be the result of taxonomic turnover in the offshore environment through time.
42 43 DISCUSSION
I. Middle Devonian Biofacies of Central Pennsylvania
I. a. Biofacies Gradients
As seen in the DCA results (Figure 12b), biofacies distribution throughout the
Hamilton interval is strongly correlated with environment, and more specifically with the myriad variables associated with water depth. An ecological gradient with water depth is thus established, with taxa comprising biofacies sorting out along the onshore-offshore basinal slope according to their preferred water depths.
Two biofacies in the Hamilton interval maintain an affinity for the shallowest depositional environment in this study. The Rhipidomella biofacies, characterized by the highest DCA Axis 1 scores, were confined to the lower shoreface deposits of the Silty
Sandstone facies. Similarly, the Rhipidomella – Devonochonetes biofacies is associated with samples collected from the Silty Sandstone facies and two samples from the proximal offshore deposits of the Sandy Siltstone facies. The overlap in facies and depositional environment and the dominance of Rhipidomella in both biofacies clusters suggest that these biofacies shared a similar preference for relatively shallow-water, lower shoreface environments along the onshore-offshore slope.
Three biofacies in this interval exhibit a preference for moderate water depths between FWB and SWB in both the proximal and distal offshore environments. The
Tropidoleptus biofacies, Tropidoleptus – Devonochonetes, and Devonochonetes biofacies all plot with intermediate DCA Axis 1 scores in Figure 12b. The Tropidoleptus biofacies
44 was sampled from both the Sandy Siltstone and Silty Mudstone facies, suggesting its
preferred depth lies along the transitional zone between proximal and distal offshore
settings. The Tropidoleptus – Devonochonetes biofacies samples are found primarily in
the Sandy Siltstone and Silty Mudstone facies, although this biofacies is also found
within the Calcareous Silty Mudstone facies. The Devonochonetes biofacies is found in both the Silty Mudstone and Calcareous Silty Mudstone facies, suggesting that its preferred water depth is slightly deeper than the Tropidoleptus and Tropidoleptus –
Devonochonetes biofacies. The overlapping of biofacies with respect to preferred water
depth is again evident and forms a clear environmental gradient.
The remaining two biofacies in this interval exhibit an affinity for the deepest
depositional environments at this locality, specifically restricted to distal offshore marine
deposits near SWB. The Ambocoelia biofacies and the Pustulatia – Longispina biofacies
are characterized by the lowest of all DCA axis 1 scores, and are confined to the distal
offshore deposits of Calcareous Silty Mudstone and Silty Mudstone facies, respectively.
The Ambocoelia biofacies cluster appears in the marly claystones of the Calcareous Silty
Mudstone facies, while the Pustulatia – Longispina biofacies are most abundant in the
distal offshore deposits of the Silty Mudstone facies. Figure 12b shows that differences
between these biofacies are expressed by separation along DCA Axis 2. This likely is due
to the taxonomic composition of these biofacies, with the Pustulatia-Longispina biofacies
of the Crooked Creek member exhibiting low DCA axis 2 scores and the Ambocoelia
biofacies of the upper Frame member exhibiting high DCA axis 2 scores. These two
biofacies have water depth preferences deeper than any of the other biofacies from this
locality.
45 One of the long-standing questions in ecological studies is whether organisms
within a community respond individualistically to environmental changes (Gleason,
1926) or, conversely, that biotic components of a community act as a tightly linked
“super-organism” (Clements, 1916). The qualitative results of this study suggest that the
Hamilton fauna responded to environmental stimuli in an individualistic manner,
following a Gleasonian view of community structure. For example, the distal offshore
deposits of the Silty Mudstone facies occur at several stratigraphic intervals throughout
the Hamilton interval at Huntingdon, however the taxa that compose the biofacies within
this depositional environment vary (i.e. Pustulatia – Longispina biofacies lower in the
interval and the Ambocoelia biofacies higher in section). This could be the result of
differential organization of the same species pool through time, or it could represent
taxonomic turnover in the offshore environment.
I. b. Ecology of Biofacies
Of the seven biofacies identified in the Hamilton Group of Pennsylvania, there are
two dominant modes that characterize the life habit ecology of these assemblages. The
dominant life habit of four biofacies is typified by reclining epifaunal suspension feeders.
Interestingly, the dominant taxa comprising the reclining epifaunal suspension feeder
guild is not the same through time. The Tropidoleptus biofacies is dominated by
Tropidoleptus reclining brachiopods, the Tropidoleptus-Devonochonetes biofacies contains a shared dominance of Tropidoleptus and Devonochonetes as the main reclining
brachiopods, and the Devonochonetes biofacies contains a dominance of Devonochonetes
reclining brachiopods. Containing a different suite of taxa, the Pustulatia – Longispina
46 biofacies also is dominated by reclining epifaunal suspension feeders, in this case
Longispina is the main contributor to the ecological pattern. The remaining three biofacies, Rhipidomella, Rhipidomella-Devonochonetes, and Ambocoelia, are dominated by pedunculate suspension feeders. The Rhipidomella and Rhipidomella-Devonochonetes biofacies are comprised mainly of attached Rhipidomella brachiopods, while the
Ambocoelia biofacies is characterized by the abundance of attached Ambocoelia brachiopods.
In most cases, the dominant life habit of each biofacies reflects adaptations allowing taxa to thrive in their preferred depositional environment. For example, the soft, muddy substrates of the Silty Mudstone and Calcareous Silty Mudstone facies are the preferred environments for the Devonochonetes, Pustulatia-Longispina, and partly the
Tropidoleptus and Tropidoleptus-Devonochonetes (which also exist in Sandy Siltstone facies) biofacies. All of these biofacies are dominated by reclining epifaunal suspension feeders. Therefore, these taxa were adapted to living on top of the substrate, as firm and stable substrates were not available which would promote attachment (Ager, 1967;
Brower and Nye, 1991). Additionally, the relative abundance of burrowing bivalves and gastropods within each biofacies also supports adaptation for living within soft, muddy substrates (see Appendix III). Conversely, the Rhipidomella and Rhipidomella-
Devonochonetes biofacies preferred the shallower, lower shoreface environments of the
Silty Sandstone facies. This environment provided a firm substrate for pedicle attachment, and thus these biofacies are dominated by pedunculate suspension feeders and exhibit a virtual lack of burrowing bivalves and gastropods (Brower and Nye, 1991).
47 The Ambocoelia biofacies presents a more complicated story. This biofacies is found within the relatively deep water deposits of the Calcareous Silty Mudstone facies, however, this biofacies is also characterized by the dominantly pedunculate suspension feeding life habit of the Ambocoelia brachiopods. This brachiopod genus has been
reported in many studies to inhabit deep, dysoxic water depths, and its designated
biofacies has been characterized by low diversity and high dominance (Brower and Nye,
1991; Brett et al., 2007; Zambito et al., 2008). Perhaps the more important factor driving
the dominance of this brachiopod in the Ambocoelia biofacies is its generalized and
opportunistic life history (Brower and Nye, 1991).
I. c. Oxygenation and Stratification of the Appalachian Basin
While the differences in depositional environments between the coarse-grained
facies (Sandy Siltstone and Silty Sandstone facies) and the fine-grained facies in this
study are readily identifiable (Silty Mudstone and Calcareous Silty Mudstone facies), the
environmental differences within the fine-grained facies are much more difficult to discern. It is important to understand the environmental variation implied by fine grained siliciclastics because they may elicit different biotic response and drive biotic patterns, the cause of which would otherwise be unrecognizable from lithologic analysis alone
(Ver Straeten et al., 2011). For instance, the relatively deeper water deposits of the Silty
Mudstone and Calcaerous Silty Mudstone facies are lithologically very similar but contain a different suite of biofacies between them (Longispina-Pustulatia in Silty
Mudstone facies and Ambocoelia in Calcareous Silty Mudstone facies), thus requiring a
multiproxy approach to further resolve potential environmental differences.
48 Recently, a study by Baird et al. (2011) assessed paleo-oxygen levels in the late
Givetian during deposition of the Tully Formation, which overlies the Mahantango
Formation. The authors develop a model to suggest that during Tully carbonate deposition in New York, a depocenter existed in Pennsylvania which acted as a clastic trap, effectively removing siliciclastic sediment from the New York carbonate platform.
Additionally, the water mass was stratified as a consequence of pycnocline development, which divided northward-flowing, warmer, denser saline water below from southward- flowing, cooler, oxygenated waters above. This stratification created dysoxic conditions in the Tully Formation of Pennsylvania. The authors do note, however, that during the latest Hamilton interval sea level rise allowed relatively deeper water biofacies to shift into dysoxic Hamilton environments (see also Baird and Brett, 2008).
The development of dysoxic environments during the latest Hamilton interval is likely what is occurring in the fine-grained shale deposits of central Pennsylvania, as well. This rise in base level is reflected sedimentologically and biologically. The lowest facies of the Frame Member begins with a bed of coarser-grained vfL sand (see Figure 4).
Directly below this bed is a covered interval, which may have also included sandy deposits. If this were the case, the lowermost Frame Member may be the shallowest deposits of the Sandy Siltstone facies represented here. Biologically, this zone of the
Frame Member is represented by the moderate to shallow-water depth Tropidoleptus biofacies. Higher in the section, the Frame Member becomes slightly finer-grained, likely representing a minor increase in water depth. Again, this base level rise is coincident with the appearance of a relatively deeper water Devonochonetes biofacies. Finally, highest in the Frame Member is the transition between Silty Mudstone facies and Calcareous Silty
49 Mudstone facies, which is also coincident with the shift to deep water Ambocoelia biofacies. As mentioned above, the Ambocoelia biofacies is associated with the low- diversity, high-dominance qualities of dysoxic environments. This transition in the uppermost Hamilton interval in Huntingdon, Pennsylvania corroborates the environmental changes outlined by Baird et al. (2011) in New York State.
II. Qualitative Comparison of Pennsylvania and New York Biofacies
Of the seven biofacies identified in this study, three (and perhaps four) similar biofacies are recognized in the Hamilton Group in New York State (Brett and Baird,
2007; Bonuso et al., 2002; Brower and Nye, 1991; Vogel et al., 1987). The Tropidoleptus,
Tropidoleptus-Devonochonetes, and Ambocoelia biofacies of this study share similar taxonomic membership and relative abundance structure to the Tropidoleptus and
Ambocoelia assemblages described both qualitatively (Vogel et al., 1987; Brower and
Nye, 1991) and quantitatively (Bonuso et al., 2002; Brett et al., 2007). Additionally, the environments of deposition for each of these assemblages in New York parallel the depositional environments these biofacies were collected from in central Pennsylvania.
The Devonochonetes biofacies of this study has also been characterized in New York, albeit with slight variations on the taxonomic membership. These biofacies include the
Mucrospirifer-chonetid assemblage of Vogel et al. (1987), Mucrospirifer mucronatus assemblage of Brower and Nye (1991), Devonochonetes-Mucrospirifer-Longispina biofacies of Bonuso et al. (2002), and the Diverse brachiopod biofacies of Brett et al.
(2007). All of these biofacies are found within the same depositional environment to the
50 Devonochonetes biofacies in this study. The Pustulatia-Longispina biofacies of this study has not been identified as a distinct assemblage by other authors in New York, however these taxa do occur within previously described biofacies in New York, largely falling within the Diverse brachiopod biofacies of Brett et al. (2007) and the Devonochonetes-
Mucrospirifer-Longispina biofacies of Bonuso et al. (2002). The remaining two biofacies,
Rhipidomella and Rhipidomella-Devonochonetes have not been identified as distinct biofacies in New York. This is likely because the preferred environment of deposition and preferred substrate composition for these biofacies is much shallower and coarser-grained than the environments observed in New York. Interestingly, Rhipidomella brachiopods were reportedly associated with the relatively shallow-water Tropidoleptus carinatus assemblage of Brower and Nye (1991), suggesting that if the preferred shallow water, sediment-rich environments of these biofacies were to present themselves in New York as they do in Pennsylvania, these taxa would likely occupy it. Brett et al. (2007) developed a model for the preferred depths of biofacies and their laterally equivalent, turbidity-rich biofacies in New York State. Figure 14 expands on this model to include the more proximal biofacies of Pennsylvania identified in this study.
The dominant life habit distribution of biofacies and the biota comprising them are qualitatively similar between the biofacies of New York and those in Pennsylvania described in this study. The Tropidoleptus and Tropidoleptus-Devonochonetes biofacies are dominated by reclining suspension feeders in Pennsylvania as they are in New York
(64.2% in Brower and Nye, 1991; approximately 65.0% in Bonuso et al., 2002; 77.9% average in this study). The Devonochonetes biofacies are also dominated by reclining suspension feeders in both geographic regions (89.0% in Brower and Nye, 1991;
51 FIGURE 14. Distribution of Middle Devonian Hamilton biofacies in New York along a bathymetric gradient (Brett et al. 2007). Shaded biofacies indicate that a New York biofacies is similar to biofacies present in Pennsylvania and identified in this study. The
Rhipidomella biofacies in this study has no analogue in New York, but would likely be located in shallow, turbid, lower shoreface environment.
52 approximately 65.0% in Bonuso et al., 2002; 89.2% in this study). Finally, the dominance of the pedunculate life history within the Ambocoelia biofacies is similar between
Pennsylvania and New York (93.2% in Brower and Nye, 1991 and 86.5% in this study).
These qualitative results suggest that, in a general sense, Hamilton biofacies are geographically widespread throughout the Appalachian basin during Middle Devonian time, allowing the taxa to freely move to their preferred habitats, wherever those environments occurred. Additionally at a coarse level of resolution, taxa that are abundant in local biofacies appear to be abundant over larger spatial scales as well. For example, this study has found the brachiopod genus Devonochonetes to be ubiquitous throughout the Hamilton interval in Huntingdon, complementing the studies which highlight the chonetid or “diverse brachiopod biofacies” of New York (Brett et al, 2007). In a qualitative sense, this conclusion is in accord with the findings of Holland and
Patzkowsky (2004), which concluded that preferred environment is a highly conserved attribute of biofacies through time. What has not been shown is how preferred environment may vary across different geographic ranges, and this result shows that indeed preferred environment is qualitatively conserved.
Additionally, this study recognizes three novel biofacies that have not been recognized in faunal studies of the Hamilton Group in New York State. The deep water
Pustulatia-Longispina biofacies does not occur in New York samples, however
Longispina has been reported occurring within New York biofacies with reduced abundances (Brower and Nye, 1991). Surprisingly, no analogues of the Rhipidomella or
Rhipidomella-Devonochonetes biofacies are identified in New York. This is likely due to the more coarse-grained, siliciclastic nature of the shallow water deposits in central
53 Pennsylvania, owing to the proximity of the Huntingdon outcrop to the Acadian sediment source. Other environmental differences that could be influencing the occurrence of biofacies include turbidity, sedimentation rate, and nutrient availability. This suggests that the main differences between New York and Pennsylvania Hamilton biofacies is simply due to the spatial occurrence of preferred habitats. Additional high resolution quantitative studies of the Hamilton Group fauna throughout Pennsylvania may reveal more biofacies that have previously gone unrecognized within a very important paleontological interval.
III. Quantitative Comparison of Pennsylvania and New York Biofacies
III. a. Gradient Comparison
The combined DCA analysis of the Savarese et al. New York collections and the
Pennsylvania collections shows an interesting pattern of separation along DCA axes.
(Figure 15). DCA Axis 1 is not related to water depth, but rather represents a geographic separation of the Pennsylvania and New York samples. This suggests that the geographic differences between localities generate a stronger signal to the underlying structure of the data than does water depth. The Pennsylvania samples from this study characterize the low DCA Axis 1 scores (-3.0 to 1.0), while New York samples from the Savarese et al. study characterize high DCA Axis 1 scores (1.0 to 4.0). It is difficult to interpret separation along DCA Axis 1 within the individual studies’ range of DCA Axis 1 scores, suggesting that the separation along DCA Axis 1 due to the large geographic differences between study sites (New York vs. Pennsylvania) mask any geographic signal within a study site. This geographic separation is most likely related to proximity to the delta
54 Pennsylvania Biofacies New York Biofacies
+ Rhipidomella ● Favosites + Rhipidomella - Devonochonetes ● Eridophyllum – ramose favositid + Tropidoleptus ● Heliophyllum – Heterophrentis + Devonochonetes, Tropid.-Dev. ● Pseudoatrypa - Stereolasma + Ambocoelia ● Ambocoelia - chonetid + Pustulatia - Longispina ● Leiorhynchus - styliolinid Deep
Shallow w
Proximal Distal delta delta
FIGURE 15. DCA Analysis comparing Pennsylvania samples (this study) with New
York samples (Savarese et al., 1986). Pennsylvania samples are represented by crosses
and New York samples are represented by circles.
55 front, which include factors such as turbidity, sedimentation rate, and nutrient flux.
Differences between study sites do not include climate (situated at approximately the
same latitude/longitude) or salinity (all samples are open marine).
The water depth gradient does emerge along DCA Axis 2. Samples collected from
shallow water environments exhibit low DCA Axis 2 scores, while samples collected
from deeper water environments exhibit high DCA Axis 2 scores. The DCA Axis 2 scores
within the Pennsylvania samples of this study do not span as large a range of values as
the DCA Axis 2 scores of the New York samples do, and appear truncated at a maximum
value of 1.2. This suggests that the New York samples contain additional deeper water
environments that either do not exist in the more proximal depositional environments of
central Pennsylvania, or that these environments do exist but were not preserved in
outcrop at the study locality.
The larger comprehensive taxonomic list for the Hamilton Interval was examined
for Pennsylvania (Ellison, 1965) and New York (Linsley, 1994) to ensure that the
differentiation between this study’s data set and the Savarese data set was a true ecologic
signal and not the result of uneven sampling (Table 3). Six brachiopod genera were found
throughout central Pennsylvania that have not been reported in New York, including
Schizobolus, Petrocrania, Leptaena, Schuchertella, Douvillina, and Atrypa. The remaining 34 brachiopod genera reported for Pennsylvania have been reported in New
York, but account for only 34% of the total reported brachiopod genera throughout New
York (34 of 98 genera). Five bivalve genera were found in central Pennsylvania that have not been reported in New York, including Prothyris, Nuculana, Parallelodon,
Glyptodesma, and Conocardium. The remaining 19 bivalve genera reported for
56 TABLE 3. Overall Hamilton Group generic diversity differences between central
Pennsylvania (Ellison, 1965) and New York State (Linsley, 1994). Bryozoan and coral genera are not reported for New York State. Taxonomic lists are compiled from presence/absence data.
Genera Unique to Genera Unique to Total Genera Shared Genera (%)
PA NY
Brachiopoda 6 64 98 34 (34%)
Bivalvia 5 26 45 19 (42%)
Gastropoda 3 37 45 8 (18%)
Trilobita 0 19 24 5 (21%)
Cephalopoda 4 20 24 0 (0%)
57 Pennsylvania constitute 42% of the total bivalve genera reported for New York (45
genera). Three gastropod genera were reported for Pennsylvania that have not been
reported in New York, including Bucanopsis, Naticonema, and Ianthinopsis. The remaining 8 gastropod genera in Pennsylvania account for only 18% of the total gastropod diversity reported for New York (8 of 45 genera). All five trilobite genera reported in Pennsylvania have been recorded in New York, though this only constitutes
21% of the total trilobite genera reported (5 of 24). All four cephalopod genera reported for Pennsylvania differ from the 20 genera reported for New York State. Information regarding the total diversity of corals and bryozoans are not reported for New York. It is unclear whether more sampling across Pennsylvania would cause the overall diversity of the Pennsylvania taxa to increase towards that of New York. Nevertheless, there are taxa that appear in Pennsylvania and New York that could be driving the separation of the two data sets along DCA Axis 1. Additionally, though more sampling in Pennsylvania could cause the taxonomic list for the Hamilton Group to be more regionally homogeneous, the relative abundance of taxa can play a large role in differentiating paleocommunities from
Pennsylvania and New York (Bonelli et al., 2006). Unfortunately, the impact of relative abundance of all taxa cannot be gleaned from the presence/absence taxonomic lists of
Ellison (1965) and Linsley (1994), thus more high-resolution paleoecological studies are required to assess the regional variability of paleocommunity diversity.
The shared gradient information between the two study localities was explored by comparing the individual DCA analyses with one another (Figure 16). DCA sample scores for the shared taxa can be extracted from each of these graphs for use in comparison of niche parameters (Holland and Patzkowsky, 2004; Holland and Zaffos,
58 FIGURE 16. DCA Analysis comparison of onshore-offshore gradient between the
Pennsylvania samples collected in this study and the New York samples collected by
Savarese et al. (1986). For color-coding designation, refer to Figure 15.
59 2011; Patzkowsky and Holland 2012; Figure 17). This allows us to quantify differences and similarities between study sites in terms of shared taxa and their associated niche parameters. Fifteen taxa were shared between the New York and Pennsylvania study sites, detailed in Table 4.
III. b. Comparison of Niche Parameters
Preferred environment (PE) was shown to be strongly and significantly correlated between the two studies, suggesting that taxa maintain their preferred water depth across relatively large geographic ranges during this time (Spearman Rank Correlation = 0.695, p < 0.002) (Figure 17a). This is an intriguing result because the depositional environments were likely quite different, owing to Pennsylvania samples containing coarser-grained and more siliciclastic rich environments relative to the quiet, finer- grained environments of New York samples. This would suggest that the shared taxa between the two study sites either had a similar depositional environment present at a given depth (especially true of the deep samples) or the shared taxa maintained their preferred water depth regardless of the amount or rate of sedimentation. Furthermore, the significant correlation of preferred environment among study sites suggests that the ecological differences between these sites are driven by the taxa unique to each locality.
Values of environmental tolerance (ET) showed no significant, statistical correlation between the two studies (Spearman Rank Correlation = -0.0298, p < 0.28)
(Figure 17b). This result suggests that taxa become either more eurytopic or more stenotopic across relatively large geographic ranges and in differing depositional environments. The lack of correlation suggests that there are few (if any) taxa that
60 r = 0.695, P < 0.002 r = -0.029, P < 0.28
r = 0.438, P < 0.10
FIGURE 17. Correlation of preferred environment (PE), environmental tolerance (ET), and peak abundance (PA) for all shared taxa between Pennsylvania ecological data (this study) and New York State ecological data (Savarese et al.,
1986). Larger axis values for Preferred Environment indicate deeper water environments. Larger axis values for
Environmental Tolerance indicate more eurytopic taxa, while smaller axis values indicate stenotopic taxa. Larger axis values for Peak Abundance indicate a higher probability of collection for a given taxa. Spearman’s rank correlation (r) and p-values (P) are indicated on each plot, with r > 0.5 indicating that a trait is conserved between study sites.
61 TABLE 4. Genera list for Huntingdon, Pennsylvania (this study) and New York State
(Savarese et al., 1986). Rare genera (occurring in <5% of samples) are not included in this list. Shared genera are indicated in bold font.
Huntingdon, Pennsylvania (This Study) New York State (Savarese et al., 1986) Ambocoelia Devonochonetes Devonochonetes Camarotoechia Leiorhynchus Mucrospirifer Longispina Pustulatia Echinocoelia Tropidoleptus Athyris Modiomorpha Cyrtina Nuculites Douvillina Megakozlowskiella Elita Rhipidomella Mediospirifer Elita Meristella Fenestella Pholidostrophia Sulcoretepora Parazyga Actinopteria Mucrospirifer Mediospirifer Nucleospira Bembexia Productella Striacoceras Protoleptostrophia Spyroceras Pseudoatrypa Paleoneilo Rhipidomella Cornellites Pleurodictyum Protoleptostrophia Stereolasma Nuculoidea Amplexiphyllum Schuchertella Heliophyllum Grammysia Eridophyllum Phacops Cladopora Ambocoelia Blotherophyllum Longispina Aulocystis Leiorhynchus Favosites Emanuella Actinopteria Bucanopsis Cypricardinia rugose coral Modiomorpha Nuculoidea Nuculites Paleoneilo Pterochaenia Naticonema Palaeozygapleura Platyceras Greenops Phacops
62 maintain wide environmental tolerances in both proximal and distal depositional settings.
Likewise, there is a lack of taxa that maintain narrow environmental tolerances in both environmental settings. Interestingly, environmental tolerances of taxa from New York samples are wider overall (20% with environmental tolerances less than 1.0) while
Pennsylvania samples have narrower environmental tolerances overall (87% with environmental tolerances less than 1.0). For example, Longispina exhibits a large environmental tolerance in the relatively quiet water depositional environment of New
York (1.50), but has a much more reduced environmental tolerance in the sediment-rich, siliciclastic environments of Pennsylvania (0.39). This would suggest that taxa in the proximal depositional environments are more stenotopic than their counterparts in distal depositional environments. This result could also reflect differences in sample size between the study sites (i.e. increasing the number of samples increases the probability of collecting a given taxon, and may widen the taxon’s environmental tolerance). Additional collections from a broad range of environments across a large geographic range are needed to confirm this result.
Values of peak abundance (PA) are weakly and non-significantly correlated between the two studies, suggesting that environmental differences strongly influence the abundance of a given taxon between proximal and distal depositional settings (Spearman
Rank Correlation = 0.438, p < 0.10) (Figure 17c). Given the environmental differences between the study localities, it is not surprising that a shared taxon would exhibit greater abundance in one environment relative to the other. For example, Paleoneilo is abundant in the muddier, finer-grained environments of New York (peak abundance = 0.83), while its abundance greatly drops in the coarser, siliciclastic environments of Pennsylvania
63 (peak abundance = 0.30). Additionally, the correlation of peak abundance increases as taxa become more abundant, while there is large scatter in the correlation at low levels of peak abundance. Thus, the poor correlation could also be the result of difficulty in estimating the abundance of rare taxa with limited samples sizes.
The comparisons of preferred environment (PE), environmental tolerance (ET), and peak abundance (PA) indicate that although many taxa may be shared between study sites spanning a large geographic range, the niche preferences of the constituent taxa are not static. In a general sense, taxa that occur both in New York State and Pennsylvania maintain their preferred environment regardless of proximity to a siliciclastic source. On the other hand, most taxa have significantly different environmental tolerances and peak abundances influenced by their proximity to a siliciclastic source. Similar conclusions were stated in a study by Bonelli et al. (2006), who found that while many taxa were shared between two Middle Devonian coral beds in New York and Pennsylvania, the relative abundances of shared taxa between study sites were quite different. Thus despite environmental differences between study localities, a given taxon’s niche appears fixed to a preferred environment, however the environmental tolerance and peak abundance of that taxon’s niche is malleable. This finding agrees with many other paleoecological studies which state that associations of taxa are the result of shared environmental preferences, rather than a tightly organized system of biotic interactions.
64 CONCLUSIONS
1. The Hamilton fauna of Huntingdon, Pennsylvania is characterized by seven biofacies
based on cluster analysis and detrended correspondence analysis. The distribution of
these biofacies is controlled primarily by factors associated with water depth based on an
interpretation of depositional environments in the Huntingdon section. Biofacies are not
discrete groups, but rather form an ecological gradient along an onshore-offshore
transect.
2. The Tropidoleptus, Tropidoleptus-Devonochonetes, Devonochonetes, and Ambocoelia
biofacies recognized in the Hamilton Group of Huntingdon, Pennsylvania share similar
characteristics to biofacies found in New York State. Qualitatively, taxonomic
membership and life history traits of each biofacies are similar across a large geographic
range within the Appalachian Basin, however further quantitative studies are needed to
bolster this conclusion.
3. Three novel biofacies were identified within the Hamilton Group of Huntingdon,
Pennsylvania. The deep water Pustulatia-Longispina biofacies is not recognized in New
York, although Longispina does occur within other biofacies, albeit with reduced
abundance. The Rhipidomella and Rhipidomella-Devonochonetes biofacies, however, have no analogue in the Hamilton Group of New York. Further examination and classification of biofacies throughout Pennsylvania may lead to the discovery of more biofacies within this paleontologically important interval.
65 4. The distribution of the Ambocoelia biofacies within the Frame Shale Member of the
Mahantango Formation is consistent with the oxygenation and ocean stratification model of Baird et al. (2011). Within the late Hamilton interval, a rise in sea level causes a shift from shallower, oxygenated facies and biofacies associations to deeper, dysoxic facies and biofacies near the contact with the Tully Formation. This example underscores the importance of multiproxy approaches (sedimentological, paleontological, geochemical) to understand the depositional environment of fine-grained siliciclastic mudstones.
5. Comparing niche parameters for shared taxa existing in both Pennsylvania and New
York produced informative results for preferred environment (PE), environmental tolerance (ET), and peak abundance (PA). Preferred environment is a strongly correlated and statistically significant between the two geographic areas, suggesting that PE is a relatively stable throughout the foreland basin. Environmental tolerance is weakly correlated between the two study localities, likely reflecting a given taxon’s preference for either proximal or distal depositional environments. Genera appear more stenotopic in the disturbed, sediment-laden proximal environments, while genera are more eurytopic in relatively tranquil, sediment-free distal environments. Peak abundance is also poorly conserved between the two study sites, and also reflects how taxa respond to proximal or distal depositional environments.
6. Further quantitative paleontological and sequence stratigraphic studies are needed within the Hamilton Group across the Appalachian foreland basin to refine further our understanding of the formation of ecological gradients and their geographic variability.
66 REFERENCES
AGER, D.V., 1967, Brachiopod Paleoecology: Earth-Science Reviews, v. 3, p. 157-179.
BAIRD, G.C., and BRETT, C.E., 2008, Late Givetian Taghanic bioevents in New York State: New discoveries and questions: Bulletin of Geosciences, v. 83, p. 357-370.
BAIRD, G.C., ZAMBITO, J.J., IV, and BRETT, C.E., 2011, Genesis of unusual lithologies associated with the Late Middle Devonian Taghanic Biocrisis in the Type Taghanic Succession of New York State and Pennsylvania: Palaeogeography, Palaeoclimatology, Palaeoecology, in press.
BLAKEY, R., 2011, North American paleogeographic maps, Middle Devonian (385 Ma), Paleogeography and geologic evolution of North America, updated March 2011, http://cpgeosystems.com/namD385.jpg. Checked January 2012.
BONELLI, J.R., BRETT, C.E., MILLER, A.I., and BENNINGTON, J.B., 2006, Testing for faunal stability across a regional biotic transition: Quantifying stasis and variation among recurring coral biofacies in the Middle Devonian Appalachian Basin: Paleobiology, v. 32, p. 20-37.
BONUSO, N., 2001, Quantitative paleoecology of the Hamilton Group of central New York: Unpublished M.S. thesis, Syracuse University, Syracuse, New York, 96 p.
BONUSO, N., NEWTON, C.R., BROWER, J.C., and IVANY, L.C., 2002a, Does coordinated stasis yield taxonomic and ecologic stability?: Middle Devonian Hamilton Group of central New York: Geology, v. 30, p. 1,055-1,058.
BONUSO, N., NEWTON, C.R., BROWER, J.C., and IVANY, L.C., 2002b, Statistical testing of community patterns: Uppermost Hamilton Group, Middle Devonian (New York: USA): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 185, p. 1-24.
BRETT, C.E., and BAIRD, G.C., 1985, Carbonate shale cycles in the Middle Devonian of New York: An evaluation of models for the origin of limestones in terrigenous shelf sequences: Geology, v. 13, p. 324-327.
BRETT, C.E., and BAIRD, G.C., 1986, Symmetrical and upward shallowing cycles in the Middle Devonian of New York: Implications for the punctuated aggradational cycle hypothesis: Paleoceanography, v. 1, 16 p.
BRETT, C.E., and BAIRD, G.C., 1995, Coordinated stasis and evolutionary ecology of Silurian to Middle Devonian marine biotas in the Appalachian basin, in Erwin, D., and Anstey, R., eds., New Approaches to Speciation in the Fossil Record: Columbia University Press, New York, p. 285-315.
67 BRETT, C.E., and BAIRD, G.C., 1996, Middle Devonian sedimentary cycles and sequences in the northern Appalachian basin, in Witzke, B.J., Ludvigson, G.A., and Day, J., eds., Paleozoic Sequence Stratigraphy: Views from the North American Craton: Geological Society of America Special Paper, v. 306, p. 213- 241.
BRETT, C.E., BAIRD, G.C., and MILLER, K.B., 1986, Sedimentary cycles and lateral facies gradients across a Middle Devonian shelf-to-basin ramp, Ludlowville Formation, Cayuga Basin: in Cisne, J., ed., New York State Geological Association Guidebook, 58th Annual Meeting, p. 81-127.
BRETT, C.E., SPEYER, S.E., and BAIRD, G.C., 1986, Storm-generated sedimentary units: Tempestite proximality and event stratification in the Middle Devonian Hamilton Group of New York, in Brett, C.E., ed., Dynamic Stratigraphy and Depositional Environments of the Middle Devonian Hamilton Group in New York State Part I: New York State Museum Bulletin, v. 457, p. 129-156.
BRETT, C.E., HENDY, A.W., BARTHOLOMEW, A.J., BONELLI, J., and McLAUGHLIN, P.I., 2007, Response of shallow marine biotas to sea-level fluctuations: A review of faunal replacement and the process of habitat tracking: PALAIOS, v. 22, p. 228-244.
BRETT, C.E., BARTHOLOMEW, A.J., and BAIRD, G.C., 2007, Biofacies recurrence in the Middle Devonian of New York State: An example with implications for evolutionary paleoecology: PALAIOS, v. 22, p. 306-324.
BROWER, J.C., and NYE, O.B., Jr., 1991, Quantitative analysis of paleocommunities in the lower part of the Hamilton Group near Cazenovia, New York, in Landing, E. and Brett, C.E., eds., Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York State, Part II: New York State Museum Bulletin, v. 469. p. 37-74.
CLEMENTS, F.E., 1916, Plant Succession: An Analysis Of The Development Of Vegetation: Carnegie Institution of Washington, Publication 242, Washington, D.C., 512 p.
DROSER, M.L., and BOTTJER, D.J., 1986, A semiquantitative field classification of ichnofabric: Journal of Sedimentary Petrology, v. 56, p. 558-559.
ELLISON, R.L., 1963, Faunas of the Mahantango Formation of south-central Pennsylvania: Pennsylvania Topographic and Geologic Survey, General Geology Report 39, p. 201-212.
ELLISON, R.L., 1965, Stratigraphy and Paleontology of the Mahantango Formation in South-Central Pennsylvania: Pennsylvania Geological Survey, General Geology Report 48, 263 p.
68 ETTENSOHN, F.R., 1985, The Catskill Delta complex and the Acadian Orogeny: A model: Geological Society of America Special Paper, v. 201, p. 39-49.
FAILL, R.T., HOSKINS, D.M., and WELLS, R.B., 1978, Middle Devonian stratigraphy in central Pennsylvania – a revision: Pennsylvania Geological Survey, General Geology Report 70, 28 p.
FAILL, R.T., 1986, Guidebook for the 51st annual field conference of Pennsylvania geologists: Selected geology of Bedford and Huntingdon counties: Pennsylvania Topgraphic and Geologic Survey, 227 p.
GLEASON, H., 1926, The individualistic concept of the plant association: Bulletin of the Torrey Botanical Club, v. 53, p. 1-20.
GOLDRING, R., and BRIDGES, P., 1973, Sublittoral sheet sandstones: Journal of Sedimentary Petrology, v. 43, p. 736-747.
HAYEK, L.C., and BUZAS, M.A., 1997, Surveying Natural Populations: Columbia University Press, New York, 563 p.
HOLLAND, S.M., MILLER, A.I., MEYER, D.L., and DATILLO, B.F., 2001, The detection and importance of subtle biofacies within a single lithofacies: the Upper Ordovician Kope Formation of the Cincinnati, Ohio region: PALAIOS, v. 16, p. 205-217.
HOLLAND, S.M., and PATZKOWSKY, M.E., 2004, Ecosystem structure and stability: middle Upper Ordovician of central Kentucky, USA: PALAIOS, v. 19, p. 316- 331.
HOLLAND, S.M., and PATZKOWSKY, M.E., 2007, Gradient ecology of a biotic invasion: Biofacies of the type Cincinnatian Series (Upper Ordovician), Cincinnati, Ohio Region, USA: PALAIOS, v. 22, p. 392-407.
HOLLAND, S.M., and ZAFFOS, A., 2011, Niche conservatism along an onshore- offshore gradient: Paleobiology, v. 37, p. 270-286.
KAISER, R.W., 1972, Delta cycles in the Middle Devonian of central Pennsylvania: PhD Thesis, Johns Hopkins University, Baltimore, Maryland, 183 p.
KAUFMANN, B., 2006, Calibrating the Devonian time scale: A synthesis of U-PB ID- TIMS ages and conodont stratigraphy: Earth Science Reviews, v. 76, p. 175-190.
KOHL, D., SLINGERLAND, R., ARTHUR, M., BRACHT, R., and ENGELDER, T., 2012, Sequence stratigraphy and depositional environments of the Shamokin (Union Springs) Mbr., Marcellus Fm. and associated strata in the Middle Appalachian Basin: AAPG Bulletin, in press.
69 LINSLEY, D.M., 1994, Devonian paleontology of New York: Paleontological Research Institution, Special Publication 21, 472 p.
McCOLLUM, L.B., 1991, Revised stratigraphy, sedimentology, and paleoecology of the Ledyard Member, Ludlowville Formation, New York, in Landing, E. and Brett, C.E., eds., Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York State, Part II: New York State Museum Bulletin, v. 469, p. 107-128.
McCUNE, B., and GRACE, J.B., 2002, Analysis of Ecological Communities: MjM Software Design, Gleneden Beach, Oregon, 300 p.
OLSZEWSKI, T.D., and PATZKOWSKY, M.E., 2001, Measuring recurrence of marine biotic gradients: A case study from the Pennsylvanian-Permian midcontinent: PALAIOS, v. 16, p. 444-460.
PATZKOWSKY, M.E., 1995, Gradient analysis of Middle Ordovician brachiopod biofacies: biostratigraphic, biogeographic, and macroevolutionary implications: PALAIOS, v. 10, p. 154-179.
PATZKOWSKY, M.E., and HOLLAND, S.M., 1997, Patterns of turnover in Middle and Upper Ordovician brachiopods of the eastern United States: A test of coordinated stasis: Paleobiology, v. 23, p. 420-443.
PATZKOWSKY, M.E., and HOLLAND, S.M., 1999, Biofacies replacement in a sequence stratigraphic framework: Middle and Upper Ordovician of the Nashville Dome, Tennessee, USA: PALAIOS, v. 14, p. 301-323.
PATZKOWSKY, M.E., and HOLLAND, S.M., 2007, Diversity partitioning of a late Ordovician marine biotic invasion: controls on diversity in regional ecosystems: Paleobiology, v. 33, p. 295-309.
PATZKOWSKY, M.E., and HOLLAND, S.M., 2012, Stratigraphic Paleobiology: University of Chicago Press, Chicago, Illinois, 256 p.
PRAVE, A.R., DUKE, W.L., and SLATTERY, W., 1996, A depositional model for storm- and tide-influenced prograding siliciclastic shorelines from the Middle Devonian of the central Appalachian foreland basin, USA: Sedimentology, v. 43, p. 611-629.
SAVARESE, M., GRAY, L.M., and BRETT, C.E., 1986, Faunal and lithologic cyclicity in the Centerfield Member (Middle Devonian: Hamilton Group) of western New York: A reinterpretation of depositional history, in Brett, C.E., ed., Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York State, Part I: New York State Museum Bulletin, v. 458, p. 32-56.
70 SCARPONI, D., and KOWALEWSKI, M., 2004, Stratigraphic paleoecology: Bathymetric signatures and sequence overprint of mollusk associations from late Quaternary sequences of the Po Plain, Italy: Geology, v. 32, p. 989-992.
SCOTESE, C.R., and McKERROW, W.S., 1990, Revised world maps and introduction, in McKerrow, W.S., and Scotese, C.R., eds., Paleozoic Paleogeography and Biogeography: Geological Society of London, Geological Society Memoirs, v. 12, p. 1-21.
SEPKOSKI, J.J., Jr., 1987, Environmental trends in extinction during the Paleozoic: Science, v. 235, p. 64-66.
SEPKOSKI, J.J., Jr., 1988, Alpha, beta, or gamma: where does all the diversity go?: Paleobiology, v. 14, p. 221-234.
SEPKOSKI, J.J., Jr., and MILLER, A.I., 1985, Evolutionary faunas and the distribution of Paleozoic benthic communities in space and time, in Valentine, J.W., ed., Phanerozoic Diversity Patterns: Princeton University Press, Princeton, New Jersey, p. 153-190.
SESSA, J.A., 2003, The dynamics of rapid, asynchronous biotic turnover in the Middle Devonian Appalachian Basin: Unpublished M.S. thesis, University of Cincinnati, Cincinnati, Ohio, 86 p.
VAIL, P.R., MITCHUM, R.M., Jr., and THOMPSON, S., III., 1977, Seismic stratigraphy and global changes of sea level; Part 3, Relative changes of sea level from coastal onlap: American Association of Petroleum Geologists Memoir, p. 63-81.
VAIL, P.R., AUDEMARD, F., BOWMAN, S.A., EISNER, P.N., PEREZ-CRUZ, G., 1991, The stratigraphic signatures of tectonics, eustacy and sedimentology; an overview: in Ricken, W. and Seilacher, A., eds., Cycles and Events in Stratigraphy: Springer Verlag, Berlin, p. 617-659.
VALENTINE, J.W., and MOORES, E.M., 1970, Plate-tectonic regulation of faunal diversity and sea level: a model: Nature, v. 228, p. 657-659.
VER STRAETEN, C.A., 2007, Basinwide stratigraphic synthesis and sequence Stratigraphy, upper Pragian, Emsian, and Eifelian stages (Lower to Middle Devonian), Appalachian Basin, in Becker, R.T., and Kirchgasser, W.T., eds., Geological Society Special Publications, Volume 278, Geological Society of London, London, United Kingdom (GBR), p. 39-81.
71 VER STRAETEN, C.A., and BRETT, C.E., 2006, Pragian to Eifelian strata (middle Lower to lower Middle Devonian), northern Appalachian Basin; stratigraphic nomenclatural changes: Northeastern Geology and Environmental Sciences, v. 28, p. 80-95.
VOGEL, K.P., GOLUBIC, S., and BRETT, C.E., 1987, Endolith associations and their relation to facies distribution in the Middle Devonian of New York State, USA: Lethaia, v. 20, p. 263-290.
VER STRAETEN, C.A., BRETT, C.E., and SAGEMAN, B.B., 2011, Mudrock sequence stratigraphy: A multi-proxy (sedimentological, paleobiological, and geochemical) approach, Devonian Appalachian Basin: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 304, p. 54-73.
ZAMBITO, J.J., IV, MITCHELL, C.E., and SHEETS, H.D., 2008, A comparison of sampling and statistical techniques for analyzing bulk-sampled biofacies composition: PALAIOS, v. 23, p. 313-321.
72 APPENDIX A. Latitude and longitude measurements for measured stratigraphic section at Huntingdon, Pennsylvania, USA. Latitude and longitude were taken at either the start or the end of each covered interval.
Backbone Ridge start: (40º 29’ 7.61” N, 78º 1’ 37.02” W)
Crooked Creek end: (40º 29’ 3.08” N, 78º 1’ 27.01” W)
Donation start/end: (40º 28’ 55.30” N, 78º 1’ 12.50” W)
Frame start: (40º 28’ 45.60” N, 78º 0’ 58.34” W)
Tully start: (40º 28’ 44.16” N, 78º 0’ 52.54” W)
73 APPENDIX B. Raw API Gamma Ray Data collected from the Mahantango Formation in
Huntingdon, PA.
API Height API Height API Height API Height API Height (cont) (cont) (cont) (cont) 0 0 136.897 11.2736 97.088 77.7036 116.789 98.43 97.142 205.2476 118.339 0.1524 126.865 11.426 90.721 78.0084 100.245 98.7348 102.798 205.6047 111.747 0.3048 114.727 11.5784 84.797 78.3132 119.529 99.0396 86.209 205.9618 100.41 0.4572 128.05 11.7308 100.267 78.618 110.113 99.3444 89 206.3189 105.326 0.6096 115.473 11.8832 89.161 78.9228 115.003 99.6492 92.853 206.676 99.916 0.762 108.133 12.0356 88.166 79.2276 112.168 99.954 83.99 207.0331 116.342 0.9144 98.418 12.188 89.47 79.5324 109.431 100.2588 93.226 207.3902 103.906 1.0668 103.464 12.3404 89.027 79.8372 130.192 100.5636 89.777 207.7473 113.375 1.2192 101.965 12.4928 83.898 80.142 113.818 100.8684 78.301 208.1044 108.645 1.3716 112.555 12.6452 94.414 80.4468 104.389 101.1732 84.328 208.4615 103.789 1.524 129.058 12.7976 97.597 80.7516 115.56 101.478 96.875 208.8186 115.378 1.6764 101.066 12.95 88.045 81.0564 121.874 101.7828 96.53 209.1757 110.903 1.8288 107.438 13.1024 87.651 81.3612 93.345 102.0876 109.392 209.5328 107.073 1.9812 99.164 13.2548 96.428 81.666 110.073 102.3924 90.545 209.8899 114.26 2.1336 108.272 13.4072 90.903 81.9708 117.24 102.6972 104.676 210.247 120.212 2.286 98.79 13.5596 80.075 82.2756 96.844 103.002 103.928 210.6041 116.616 2.4384 101.796 13.712 90.809 82.5804 115.05 103.3068 68.496 210.9612 109.146 2.5908 92.862 13.8644 92.115 82.8852 118.199 103.6116 111.644 289 103.742 2.7432 109.644 14.0168 96.44 83.19 105.405 103.9164 95.652 289.3472 92.571 2.8956 99.959 14.1692 107.319 83.4948 101.865 104.2212 112.235 289.6944 122.83 3.048 97.557 14.3216 110.596 83.7996 96.041 104.526 111.586 290.0416 121.202 3.2004 91.585 14.474 116.749 84.1044 100.732 104.8308 121.521 290.3888 114.943 3.3528 109.896 14.6264 108.553 84.4092 105.64 105.1356 127.438 290.736 108.46 3.5052 85.483 69.6264 107.007 84.714 99.394 105.4404 122.933 291.0832 108.51 3.6576 92.792 69.7788 96.263 85.0188 104.436 105.7452 138.377 291.7776 110.113 3.81 104.401 69.9312 98.169 85.3236 75.902 106.05 125.495 292.1248 88.342 3.9624 92.54 70.0836 96.471 85.6284 110.425 106.3548 130.661 292.472 101.291 4.1148 90.343 70.236 104.944 85.9332 103.945 106.6596 131.128 292.8192 94.686 4.2672 92.114 70.3884 104.983 86.238 127.124 106.9644 122.599 293.1664 70.691 4.4196 84.493 70.5408 108.366 86.5428 103.251 107.2692 114.13 293.5136 71.459 4.572 84.614 70.6932 106.678 86.8476 112.463 107.574 108.49 293.8608 77.687 4.7244 93.388 70.8456 113.343 87.1524 101.848 107.8788 133.46 294.208 76.483 4.8768 88.866 70.998 85.335 87.4572 98.951 108.1836 137.32 294.5552 72.128 5.0292 85.305 71.1504 90.426 87.762 110.2 108.4884 131.787 294.9024 61.075 5.1816 90.552 71.3028 106.057 88.0668 127.13 108.7932 120.095 295.2496 76.952 5.334 98.447 71.4552 96.229 88.3716 120.246 109.098 118.234 295.5968
74 API Height API Height API Height API Height API Height (cont) (cont) (cont) (cont) 66.051 5.4864 85.2 71.6076 93.669 88.6764 102.617 109.4028 110.641 295.944 60.171 5.6388 97.571 71.76 105.24 88.9812 114.207 197 113.566 296.2912 59.163 5.7912 81.865 71.9124 93.196 89.286 93.964 197.1524 123.299 296.6384 38.399 5.9436 84.493 72.0648 99.394 89.5908 111.728 197.3048 118.865 296.9856 119.404 6.096 97.827 72.2172 113.875 89.8956 92.577 197.4572 120.485 297.3328 105.196 6.2484 81.431 72.3696 93.901 90.2004 82.934 197.6096 135.548 297.68 116.585 6.4008 94.63 72.522 101.978 90.5052 95.349 197.762 126.81 298.0272 134.165 6.5532 82.308 72.6744 111.933 90.81 93.745 197.9144 117.952 298.3744 96.172 6.7056 93.2 72.8268 113.149 91.1148 109.662 198.2192 124.549 298.7216 108.324 6.858 92.596 72.9792 104.589 91.4196 95.958 198.524 132.612 299.0688 103.924 7.0104 82.804 73.1316 111.56 91.7244 104.482 198.8288 141.395 299.416 111.789 7.1628 96.828 73.284 108.553 92.0292 117.155 199.1336 137.074 299.7632 143.222 7.3152 96.61 73.4364 104.918 92.334 89.753 199.4384 124.308 300.1104 122.426 7.4676 93.088 73.5888 105.682 92.6388 121.52 199.7432 116.866 300.4576 119.126 7.62 87.002 73.7412 97.969 92.9436 98.315 200.048 117.96 300.8048 127.599 9.14 93.031 73.8936 117.332 93.2484 101.268 200.3528 115.756 301.152 109.667 9.2924 86.274 74.046 105.435 93.5532 121.473 200.6576 112.473 301.4992 106.761 9.4448 88.562 74.3508 100.119 93.858 125.228 200.9624 130.942 301.8464 93.974 9.5972 102.047 74.6556 100.654 94.1628 119.29 201.3195 139.537 302.1936 114.803 9.7496 89.796 74.9604 97.067 94.4676 118.827 201.6766 126.489 302.5408 119.742 9.902 82.082 75.2652 118.835 94.7724 116.911 202.0337 127.806 302.888 116.181 10.0544 76.205 75.57 110.894 95.0772 103.648 202.3908 146.225 303.2352 102.322 10.2068 92.561 75.8748 118.113 95.382 111.287 202.7479 124.831 303.5824 122.115 10.3592 91.945 76.1796 105.696 95.6868 121.203 203.105 126.846 303.9296 132.45 10.5116 104.77 76.4844 101.891 95.9916 98.206 203.4621 130.19 304.2768 117.262 10.664 102.769 76.7892 104.01 96.2964 113.856 203.8192 126.177 304.624 114.227 10.8164 97.458 77.094 105.588 96.6012 105.183 204.1763 103.327 304.9712 106.539 10.9688 94.981 77.3988 106.27 96.906 107.28 204.5334 109.555 305.3184 122.835 11.1212 103.161 97.2108 117.209 204.8905 117.646 305.6656 106.981 97.5156 118.036 306.0128 106.138 97.8204 114.347 306.36 99.811 98.1252
75 APPENDIX C. Biofacies composition and life history traits. Biofacies composition is calculated as the relative abundance of ALL taxa (no rare taxa removed). Life history traits are categorized following Bonuso et al. (2002).
Biofacies A: Devonochonetes Devonochonetes 46.6% Mucrospirifer 21.2% Nuculites 9.5% Paleoneilo 4.0% Pustulatia 2.6% bivalve indet. 2.3% Grammysia 1.2% Camarotoechia 1.9% Less than 1%: Tropidoleptus, Modiomorpha, Megakozlowskiella, Elita, Fenestella, Sulcoretepora, Actinopteria, Mediospirifer, Bembexia, Nucula, Striacoceras, Spyroceras, Cornellites, Athyris, Protoleptostrophia, Phacops, Goniophora, Ambocoelia, Atrypa, Longispina, Douvillina, Paracyclas, Dipleura, Leiorhynchus, Protomya, Cypricardella, Emanuella, Bucanopsis, Paracyclas, Orthonota, Taeniopora, Tylothyris, Pterinopectin, tabulate coral, rugose coral, cephalopod indet., brachiopod indet., gastropod indet., orthoconic cephalopod, ostracod sp.
R:47 D: 0.7 H: 2.1 E: 0.5
Life Habit Individuals % Total Reclining Suspension Feeder 1296 76.87% Pedunculate Suspension Feeder 51 3.02% Epifaunal benthic crawlers and grazers 24 1.42% Infaunal Deposit Feeders 253 15.01% Deep Endobyssate Suspension Feeders 36 2.14% Shallow Endobyssate Suspension Feeders 8 0.47% Nektonic Carnivores 14 0.83% Infaunal Suspension Feeders 4 0.24% 1686
76 Biofacies B: Rhipidomella Rhipidomella 83.5% Megakozlowskiella 5.3% Mucrospirifer 1.3% Schuchertella 1.3% Camarotoechia 1.2% Elita 1.0% brachiopod indet. 1.0% Less than 1%: Devonochonetes, Fenestella, Sulcoretepora, Taeniopora, bivalve indet., crinoid columnals
R:14 D: 0.3 H: 0.82 E: 0.31
Life Habit Individuals % Total Reclining Suspension Feeder 20 3.79% Pedunculate Suspension Feeder 508 96.21% Epifaunal benthic crawlers and grazers 0 0.00% Infaunal Deposit Feeders 0 0.00% Deep Endobyssate Suspension Feeders 0 0.00% Shallow Endobyssate Suspension Feeders 0 0.00% Nektonic Carnivores 0 0.00% Infaunal Suspension Feeders 0 0.00% 528
Biofacies C: Rhipidomella - Devonochonetes Camarotoechia 26.7% Devonochonetes 23.3% Rhipidomella 17.8% Megakozlowskiella 6.7% Mediospirifer 5.6% Mucrospirifer 3.3% Pustulatia 2.2% Actinopteria 2.2% Protoleptostrophia 2.2% Grammysia 1.1% Spinocyrtia 1.1% Bembexia 1.1% bivalve indet. 1.1% gastropod indet. 1.1% trilobite indet. 1.1%
R:10 D: 0.84 H: 2.12 E: 0.92
Life Habit Individuals % Total Reclining Suspension Feeder 26 35.62% Pedunculate Suspension Feeder 41 56.16% Epifaunal benthic crawlers and grazers 3 4.11% Infaunal Deposit Feeders 0 0.00% Deep Endobyssate Suspension Feeders 1 1.37% Shallow Endobyssate Suspension Feeders 2 2.74% Nektonic Carnivores 0 0.00% Infaunal Suspension Feeders 0 0.00% 73
77 Biofacies D: Tropidoleptus – Devonochonetes Tropidoleptus 21.7% Devonochonetes 12.7% Mucrospirifer 7.8% Nuculites 7.6% Schuchertella 7.1% Paleoneilo 6.8% Pustulatia 4.9% Longispina 3.2% rugose coral 2.7% Grammysia 2.4% brachiopod indet. 2.4% bivalve indet. 2.2% Actinopteria 1.7% Pterinopectin 1.5% Camarotoechia 1.5% cephalopod indet. 1.2% Platyceras 1.2% Spyroceras 1.0% Megakozlowskiella 1.0% Less than 1%: Sulcoreteopora, Bembexia, Striacoceras, Cornellites, Protoleptostrophia, Nucula, Phacops, Goniophora, Ambocoelia, Atrypa, Greenops, Nuculana, Bucanopsis, Taeniopora, gastropod indet.,
R:30 D: 0.92 H: 2.94 E: 0.87
Life Habit Individuals % Total Reclining Suspension Feeder 219 65.18% Pedunculate Suspension Feeder 14 4.17% Epifaunal benthic crawlers and grazers 9 2.68% Infaunal Deposit Feeders 61 18.15% Deep Endobyssate Suspension Feeders 12 3.57% Shallow Endobyssate Suspension Feeders 9 2.68% Nektonic Carnivores 12 3.57% Infaunal Suspension Feeders 0 0.00% 336
78 Biofacies E: Pustulatia – Longispina Pustulatia 38.5% Longispina 31.0% Nucula 5.9% Leiorhynchus 4.2% Devonochonetes 3.8% Camarotoechia 3.8% bivalve indet. 2.9% Mediospirifer 2.5% brachiopod indet. 2.5% Paracyclas 1.7% Actinopteria 1.3% Less than 1%: Nuculites, Paleoneilo, Cornellites, rugose coral
R:11 D: 0.75 H: 1.8 E: 0.75
Life Habit Individuals % Total Reclining Suspension Feeder 115 76.16% Pedunculate Suspension Feeder 11 7.28% Epifaunal benthic crawlers and grazers 0 0.00% Infaunal Deposit Feeders 17 11.26% Deep Endobyssate Suspension Feeders 0 0.00% Shallow Endobyssate Suspension Feeders 4 2.65% Nektonic Carnivores 0 0.00% Infaunal Suspension Feeders 4 2.65% 151
79 Biofacies F: Ambocoelia Ambocoelia 59.0% Leiorhynchus 13.3% Emmanuella 10.0% Devonochonetes 5.5% Paleoneilo 2.4% Nuculites 1.9% brachiopod indet. 1.7% Nucula 1.2% bivalve indet. 1.0% Less than 1%: Tropidoleptus, Modiomorpha, Mediospirifer, Bembexia, Striacoceras, Cornellites, Atrypa, Greenops, Cypricardella, Mourlonia, rugose coral, crinoid columnals,
R:13 D: 0.6 H: 1.5 E: 0.6
Life Habit Individuals % Total Reclining Suspension Feeder 26 6.45% Pedunculate Suspension Feeder 346 85.86% Epifaunal benthic crawlers and grazers 2 0.50% Infaunal Deposit Feeders 23 5.71% Deep Endobyssate Suspension Feeders 1 0.25% Shallow Endobyssate Suspension Feeders 1 0.25% Nektonic Carnivores 3 0.74% Infaunal Suspension Feeders 1 0.25% 403 Biofacies G: Tropidoleptus Tropidoleptus 69.3% Mucrospirifer 5.6% Nuculites 3.6% Paleoneilo 3.5% Devonochonetes 3.1% bivalve indet. 2.2% Camarotoechia 2.1% Mediospirifer 1.8% Ambocoelia 1.5% Less than 1%: Pustulatia, Megakozlowskiella, Rhipidomella, Fenestella, Actinopteria, Bembexia, Nucula, Cornellites, Protoleptostrophia, Grammysia, Phacops, Longispina, Bucanopsis, Lingula, Aviculopectin, Palaeozygopleura, trilobite indet., brachiopod indet., crinoid columnals
R: 21 D: 0.5 H: 1.5 E: 0.5
Life Habit Individuals % Total Reclining Suspension Feeder 610 94.87% Pedunculate Suspension Feeder 30 4.67% Epifaunal benthic crawlers and grazers 1 0.16% Infaunal Deposit Feeders 2 0.31% Deep Endobyssate Suspension Feeders 0 0.00% Shallow Endobyssate Suspension Feeders 0 0.00% Nektonic Carnivores 0 0.00% Infaunal Suspension Feeders 0 0.00% 643
80 APPENDIX D. Collection-based rarefaction analysis for each of the seven biofacies identified in Huntingdon, Pennsylvania.
81 APPENDIX E. Raw Data Matrix of all fossils collected from Mahantango Formation of
Huntingdon, Pennsylvania.
82 s u t r a a a l e t l t g d s h a e e n i o i e d a p r t l u k i o p t l o e a e s a s a q r s h r o r i a i b p l c r n s e u h l l c r e e w l l o t a o t o a f _ o f s v o i a p h e i i r l o e e s p p r r r c c o _ _ h r a t l r a h c i a l o i l a i a i b i e e r e s s l i e e t o _ s z p c l m t t a n t t p v p i x _ e c e e e e r i o e a o s e l o o o e s t t o t a p m s t l r e c i i a n l o k r b b c g d n l l l d c d s o o o i o a e a i i b c o o u i i l a o _ _ _ _ r o u u u o e t r n o n p p a c e i c d g d u a d d d d v m c c i c r i s l m y l h n t i i i i t n o r t i u o e i e b e a u u h u o u l u c e t p a r e r n n n n r Sample a D C M P T M N M N o R E c u F S A M B u u t N S S u P C UPFRAM17 12 1 18 2 1 3 4 2 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON1 0 2 0 0 0 0 0 4 0 0 68 5 2 3 1 1 0 0 0 0 0 0 0 0 0 0 0 0 DON2 0 0 3 0 0 0 0 2 0 0 65 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BB1 7 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 1 0 0 0 0 0 0 0 0 0 LIMEFRAM1 16 2 18 2 1 0 3 0 1 0 0 0 1 0 1 0 0 0 0 3 1 5 1 1 1 1 2 1 LIMEFRAM2 0 0 0 0 10 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL1 6 0 20 3 9 0 13 1 5 0 0 0 1 1 0 0 1 0 0 2 2 0 0 0 0 0 0 0 DON3 2 0 3 0 0 0 0 4 0 0 4 0 1 0 0 0 0 1 0 1 0 0 0 0 0 1 0 0 LIMEFRAM3 0 2 1 1 5 0 0 0 0 0 0 0 0 0 1 1 3 0 0 1 1 0 0 0 4 0 0 0 UPFRAM1 16 2 2 0 0 0 0 3 2 0 0 2 1 2 1 0 0 0 0 1 0 0 0 0 0 0 0 0 LIMEFRAM4 18 3 32 0 0 0 3 0 7 0 0 1 1 0 0 0 0 0 0 1 0 0 0 1 0 0 1 0 BB2 0 4 1 0 22 0 0 0 0 0 0 0 0 1 0 0 1 7 2 0 0 0 3 0 0 0 0 0 LOWCC1 16 1 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 3 0 2 0 0 0 0 0 0 3 0 UPFRAM2 4 2 0 0 11 0 0 0 1 0 0 0 1 2 0 0 0 0 0 1 0 0 0 0 0 0 2 0 LOFRAM1 0 2 1 0 25 0 0 3 2 0 0 0 0 4 0 0 0 0 0 1 0 0 0 0 0 0 8 0 LIMEFRAM5 7 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 1 0 0 0 0 0 0 7 0 UPFRAM3 38 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 3 0 0 0 0 0 0 4 0 LIMEFRAM6 29 1 11 2 0 1 5 2 4 0 0 0 0 0 0 0 2 0 0 4 0 0 0 0 0 0 8 0 UPFRAM4 10 1 10 10 1 0 0 0 0 0 0 0 1 2 0 0 0 0 1 2 0 0 0 0 0 1 4 0 UPFRAM5 5 0 0 2 4 0 0 0 2 0 0 0 1 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 DON4 0 0 0 0 0 0 0 0 0 0 15 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 LOFRAM2 49 2 45 2 0 0 0 0 1 0 0 0 2 0 1 0 0 1 3 1 0 0 0 0 0 0 2 0 BB3 10 1 2 0 25 0 0 0 0 0 1 0 1 2 0 0 0 3 0 1 0 0 0 0 0 0 0 0 LOFRAM3 5 0 1 0 38 0 5 0 1 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 HOSP 3 0 0 0 0 0 1 0 1 0 0 0 1 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM7 22 0 22 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 LIMEFRAM8 18 4 24 4 0 0 0 0 0 0 0 0 0 4 1 0 0 0 1 2 0 0 0 0 0 0 0 0 LIMEFRAM9 45 2 19 0 0 0 8 0 2 0 0 0 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 0 s u t r a a a l e t l t g d s h a e e n i o i e d a p r t l u k i o p t l o e a e s a s a q r s h r o r i a i b p l c r n s e u h l l c r e e w l l o t a o t o a f _ o f s v o i a p h e i i r l o e e s p p r r r c c o _ _ h r a t l r a h c i a l o i l a i a i b i e e r e s s l i e e t o _ s z p c l m t t a n t t p v p i x _ e c e e e e r i o e a o s e l o o o e s t t o t a p m s t l r e c i i a n l o k r b b c g d n l l l d c d s o o o i o a e a i i b c o o u i i l a o _ _ _ _ r o u u u o e t r n o n p p a c e i c d g d u a d d d d v m c c i c r i s l m y l h n t i i i i t n o r t i u o e i e b e a u u h u o u l u c e t p a r e r n n n n r Sample a D C M P T M N M N o R E c u F S A M B u u t N S S u P C LOWCC2 49 13 0 2 0 2 0 0 0 0 0 0 0 1 0 0 2 0 1 1 0 0 0 0 0 0 0 0 UPFRAM6 11 0 1 2 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 1 0 2 UPFRAM7 11 0 7 7 23 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM10 33 0 41 4 0 0 7 0 18 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 LIMEFRAM11 13 0 14 0 0 1 0 0 1 0 0 0 0 0 1 1 0 2 2 1 1 0 0 2 1 0 0 2 UPFRAM8 5 0 0 2 3 0 0 0 2 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM12 24 0 3 4 0 0 1 0 5 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 LIMEFRAM13 13 0 15 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 PAST_TUL2 29 0 5 0 0 0 4 0 9 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 PAST_TUL3 16 0 2 6 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 PAST_TUL4 39 0 7 1 0 0 5 0 21 0 0 0 0 0 0 0 0 0 0 2 0 0 0 1 0 0 0 0 LOFRAM4 59 0 8 0 1 1 0 0 2 0 0 0 0 1 0 0 0 0 0 4 0 0 0 0 1 0 0 0 LOFRAM5 2 0 10 4 114 0 3 0 3 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 CCLOW3 5 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 UPFRAM9 53 0 8 0 1 0 0 0 1 0 0 0 1 1 0 0 1 0 0 1 0 0 0 1 0 0 0 0 PAST_TUL5 2 3 0 13 0 0 0 0 0 0 0 0 0 1 0 0 2 1 0 3 0 0 0 0 0 0 1 1 UPFRAM10 36 0 4 0 4 0 2 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 10 0 UPFRAM11 6 1 10 0 84 0 2 0 0 0 0 0 1 0 0 0 0 0 0 3 0 0 0 0 0 0 11 0 LIMEFRAM14 35 1 66 4 3 1 5 0 9 0 0 0 1 2 0 0 0 0 0 2 0 0 0 0 0 0 11 0 LIMEFRAM15 12 0 1 0 0 0 0 0 2 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 LIMEFRAM16 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 2 0 0 3 1 CCLOW4 6 1 1 0 0 0 0 0 0 0 0 0 1 0 0 5 0 0 0 2 0 0 0 0 0 0 2 0 UPFRAM12 19 1 13 0 0 0 0 0 0 0 0 0 2 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 DON5 0 2 0 0 0 0 0 4 0 0 24 0 2 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 DON6 4 0 5 0 0 0 0 2 0 0 41 1 2 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC1 0 3 3 0 47 0 0 0 0 0 0 0 1 1 0 0 0 4 4 3 0 0 0 0 0 0 0 1 LIMEFRAM17 6 0 0 0 1 1 4 0 0 0 0 0 1 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 UPFRAM13 0 4 5 0 86 0 0 2 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 10 0 s u t r a a a l e t l t g d s h a e e n i o i e d a p r t l u k i o p t l o e a e s a s a q r s h r o r i a i b p l c r n s e u h l l c r e e w l l o t a o t o a f _ o f s v o i a p h e i i r l o e e s p p r r r c c o _ _ h r a t l r a h c i a l o i l a i a i b i e e r e s s l i e e t o _ s z p c l m t t a n t t p v p i x _ e c e e e e r i o e a o s e l o o o e s t t o t a p m s t l r e c i i a n l o k r b b c g d n l l l d c d s o o o i o a e a i i b c o o u i i l a o _ _ _ _ r o u u u o e t r n o n p p a c e i c d g d u a d d d d v m c c i c r i s l m y l h n t i i i i t n o r t i u o e i e b e a u u h u o u l u c e t p a r e r n n n n r Sample a D C M P T M N M N o R E c u F S A M B u u t N S S u P C LIMEFRAM18 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 UPFRAM14 0 0 8 1 34 0 0 0 2 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 2 0 UPFRAM15 38 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON7 12 0 0 2 0 0 0 2 0 0 12 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL6 0 0 4 0 54 0 0 1 0 0 0 0 1 0 0 0 0 0 0 3 0 0 0 0 0 0 3 0 LIMEFRAM19 26 0 6 2 0 0 0 0 4 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 PAST_TUL7 5 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM20 5 0 2 3 0 0 0 0 5 0 0 0 1 2 4 0 0 0 1 2 0 0 0 3 0 0 0 0 LIMEFRAM21 29 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 UPFRAM16 51 1 0 2 0 0 6 0 5 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 16 0 BB4 1 3 0 0 26 0 0 0 0 0 0 0 1 1 3 0 0 0 1 2 0 0 0 0 0 0 0 0 CCLOW5 0 0 0 0 1 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CCLOW6 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 BB5 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 DON8 0 2 0 0 0 0 0 2 0 0 70 0 2 2 0 0 0 0 0 1 0 0 0 0 0 0 0 0 DON9 0 1 0 0 0 0 0 7 0 0 48 0 2 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 UPPERCC2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a t a i r t s e a a a u i h g s a i s i a p a q c h t n r r t y s s h e a p a o a e u l a r l r _ c o a o i v a s l k b i b r u c l a a m p n e i t l l a i r p u _ t e l c o d _ r a _ a s r i i s a e i s a s _ b r h t i y d a e _ _ t l a p i s o _ o b o s l r t _ c s a a _ o e n _ t n d a s i a v e s c l a r i o i r s r p e y l d n r n d h y a p _ e n _ o c i y e _ i i p p _ r p a l y o t h r o e r p e c y l a c n a a i s m s t s l m i l l l l c i a u c o h n i c c e o c i o o o r l _ _ r i v f o o u c u u u r p e u y g m e a i t a t l y b n e t a d d o n r c u c r c c y a i r l p h i i n i a e r t i o o p h r a r o r u o i u u u y t r c h p m t a a l r n n o s e Sample o p A u u P N S G P G S c A A G L D P o D L P N P s P N N C UPFRAM17 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BB1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM2 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL1 0 0 0 0 2 22 3 1 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON3 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM3 0 0 0 0 0 0 3 0 0 0 7 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM1 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 4 2 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM4 0 0 0 0 0 0 1 0 2 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 BB2 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LOWCC1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 3 0 0 0 1 1 1 0 0 UPFRAM2 0 0 0 0 0 7 1 0 0 0 0 0 0 0 5 0 0 0 0 0 0 1 5 0 0 0 0 0 LOFRAM1 0 0 0 0 0 0 3 0 0 0 0 0 0 0 7 7 0 0 0 0 3 0 0 0 0 0 0 0 LIMEFRAM5 0 0 0 0 0 0 0 0 0 0 0 20 1 0 0 0 0 0 0 4 0 0 0 0 0 0 2 1 UPFRAM3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 UPFRAM4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 DON4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 LOFRAM2 0 0 0 1 0 0 0 0 2 0 1 1 0 0 0 0 0 0 0 0 3 0 0 1 0 0 0 0 BB3 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 LOFRAM3 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 HOSP 0 0 0 0 0 0 0 0 0 0 0 41 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 LIMEFRAM7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 LIMEFRAM8 0 0 0 0 0 0 2 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 LIMEFRAM9 0 0 0 0 0 0 2 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 4 0 a t a i r t s e a a a u i h g s a i s i a p a q c h t n r r t y s s h e a p a o a e u l a r l r _ c o a o i v a s l k b i b r u c l a a m p n e i t l l a i r p u _ t e l c o d _ r a _ a s r i i s a e i s a s _ b r h t i y d a e _ _ t l a p i s o _ o b o s l r t _ c s a a _ o e n _ t n d a s i a v e s c l a r i o i r s r p e y l d n r n d h y a p _ e n _ o c i y e _ i i p p _ r p a l y o t h r o e r p e c y l a c n a a i s m s t s l m i l l l l c i a u c o h n i c c e o c i o o o r l _ _ r i v f o o u c u u u r p e u y g m e a i t a t l y b n e t a d d o n r c u c r c c y a i r l p h i i n i a e r t i o o p h r a r o r u o i u u u y t r c h p m t a a l r n n o s e Sample o p A u u P N S G P G S c A A G L D P o D L P N P s P N N C LOWCC2 0 0 0 3 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM6 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 UPFRAM7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 LIMEFRAM10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM11 0 0 0 0 0 0 1 1 0 0 5 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 UPFRAM8 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM12 0 0 0 0 0 0 0 1 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL2 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 PAST_TUL3 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 0 0 0 1 0 PAST_TUL4 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LOFRAM4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 LOFRAM5 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 CCLOW3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 4 0 PAST_TUL5 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 UPFRAM10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM11 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM14 0 0 0 1 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM15 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 LIMEFRAM16 0 0 0 0 0 0 0 0 0 0 0 62 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 CCLOW4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM12 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 DON5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM17 0 0 0 0 0 0 0 0 0 0 1 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a t a i r t s e a a a u i h g s a i s i a p a q c h t n r r t y s s h e a p a o a e u l a r l r _ c o a o i v a s l k b i b r u c l a a m p n e i t l l a i r p u _ t e l c o d _ r a _ a s r i i s a e i s a s _ b r h t i y d a e _ _ t l a p i s o _ o b o s l r t _ c s a a _ o e n _ t n d a s i a v e s c l a r i o i r s r p e y l d n r n d h y a p _ e n _ o c i y e _ i i p p _ r p a l y o t h r o e r p e c y l a c n a a i s m s t s l m i l l l l c i a u c o h n i c c e o c i o o o r l _ _ r i v f o o u c u u u r p e u y g m e a i t a t l y b n e t a d d o n r c u c r c c y a i r l p h i i n i a e r t i o o p h r a r o r u o i u u u y t r c h p m t a a l r n n o s e Sample o p A u u P N S G P G S c A A G L D P o D L P N P s P N N C LIMEFRAM18 0 0 0 0 0 0 0 0 0 0 0 52 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 UPFRAM14 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON7 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL6 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM19 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL7 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM20 0 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM21 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPFRAM16 0 0 0 3 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BB4 0 0 0 0 1 0 0 0 0 0 0 5 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 0 CCLOW5 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 14 0 0 0 0 0 0 0 0 CCLOW6 0 0 0 0 4 0 0 0 0 0 0 9 0 0 0 0 0 0 0 33 0 0 0 0 0 0 0 0 BB5 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON9 0 0 0 0 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 UPPERCC4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DON11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a n o b n m a u a r o b z u s u y o e n s n t l i i i y t t _ s p r i _ s c c p a o b l s a a a s e s l e i t l i g p _ p e r e p c n o y o y k a o u y o z o n i l l l n l h c n n o
r o t u u i a a a k r e u c h g o c r l i t l c e o n r i m u a t v a y i Sample t E B P O s T P L M A P UPFRAM17 0 0 0 0 0 0 0 0 0 0 0 DON1 0 0 0 0 0 0 0 0 0 0 0 DON2 0 0 0 0 0 0 0 0 0 0 0 BB1 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM1 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM2 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL1 0 0 0 0 0 0 0 0 0 0 0 DON3 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM3 0 0 0 0 0 0 0 0 0 0 0 UPFRAM1 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM4 0 0 0 0 0 0 0 0 0 0 0 BB2 0 0 0 0 0 0 0 0 0 0 0 LOWCC1 0 0 0 0 0 0 0 0 0 0 0 UPFRAM2 0 0 0 0 0 0 0 0 0 0 0 LOFRAM1 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM5 27 0 0 0 0 0 0 0 0 0 0 UPFRAM3 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM6 0 0 0 0 0 0 0 0 0 0 0 UPFRAM4 0 0 0 0 0 0 0 0 0 0 0 UPFRAM5 0 0 0 0 0 0 0 0 0 0 0 DON4 0 0 0 0 0 0 0 0 0 0 0 LOFRAM2 0 0 0 0 0 0 0 0 0 0 0 BB3 0 0 0 0 0 0 0 0 0 0 0 LOFRAM3 0 2 0 0 0 0 0 0 0 0 0 HOSP 9 0 0 0 0 0 0 0 0 0 0 LIMEFRAM7 0 1 1 3 1 0 0 0 0 0 0 LIMEFRAM8 0 0 0 0 1 2 0 0 0 0 0 LIMEFRAM9 0 0 0 0 0 0 0 0 0 0 0 a n o b n m a u a r o b z u s u y o e n s n t l i i i y t t _ s p r i _ s c c p a o b l s a a a s e s l e i t l i g p _ p e r e p c n o y o y k a o u y o z o n i l l l n l h c n n o
r o t u u i a a a k r e u c h g o c r l i t l c e o n r i m u a t v a y i Sample t E B P O s T P L M A P LOWCC2 0 0 0 0 0 0 0 0 0 0 0 UPFRAM6 0 0 0 0 0 0 0 0 0 0 0 UPFRAM7 0 1 0 0 0 0 0 0 0 0 0 LIMEFRAM10 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM11 1 0 0 0 0 0 0 0 0 0 0 UPFRAM8 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM12 0 0 0 0 1 0 0 0 0 0 0 LIMEFRAM13 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL2 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL3 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL4 0 0 0 0 0 0 0 0 0 0 0 LOFRAM4 0 0 0 0 0 0 0 0 0 0 0 LOFRAM5 0 0 0 0 0 0 0 0 0 0 0 CCLOW3 0 0 0 0 1 0 0 0 0 0 0 UPFRAM9 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL5 0 0 0 0 0 0 0 0 0 0 0 UPFRAM10 0 1 0 0 0 0 0 0 0 0 0 UPFRAM11 0 3 0 0 0 0 0 0 0 0 0 LIMEFRAM14 0 0 0 0 0 0 2 0 0 0 0 LIMEFRAM15 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM16 0 0 0 0 0 0 0 0 0 0 0 CCLOW4 0 0 0 0 0 0 0 0 0 0 0 UPFRAM12 0 0 0 0 0 0 0 0 0 0 0 DON5 0 0 0 0 0 0 0 0 0 0 0 DON6 0 0 0 0 5 0 0 0 0 0 0 UPPERCC1 0 0 0 0 0 0 0 1 0 0 0 LIMEFRAM17 0 0 0 0 0 0 0 0 0 0 0 UPFRAM13 0 0 0 0 0 0 0 0 0 0 0 a n o b n m a u a r o b z u s u y o e n s n t l i i i y t t _ s p r i _ s c c p a o b l s a a a s e s l e i t l i g p _ p e r e p c n o y o y k a o u y o z o n i l l l n l h c n n o
r o t u u i a a a k r e u c h g o c r l i t l c e o n r i m u a t v a y i Sample t E B P O s T P L M A P LIMEFRAM18 6 0 0 0 0 0 0 0 0 0 0 UPFRAM14 0 0 0 0 0 0 0 0 0 0 0 UPFRAM15 0 0 0 0 0 0 0 0 0 0 0 DON7 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL6 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM19 0 0 0 0 0 0 0 0 0 0 0 PAST_TUL7 0 0 0 0 0 0 0 0 0 0 0 LIMEFRAM20 0 0 0 0 0 0 6 0 0 0 0 LIMEFRAM21 0 0 0 0 0 0 0 0 0 0 0 UPFRAM16 1 3 0 0 0 0 0 0 0 0 0 BB4 0 0 0 0 0 0 0 0 0 1 1 CCLOW5 0 0 0 0 0 0 0 0 0 0 0 CCLOW6 0 0 0 0 0 0 0 0 1 0 0 BB5 0 0 0 0 0 0 0 0 0 0 0 DON8 0 0 0 0 0 0 0 0 0 0 0 DON9 0 0 0 0 0 0 0 0 0 0 0 UPPERCC2 0 0 0 0 0 0 0 0 0 0 0 UPPERCC3 0 0 0 0 0 0 0 0 0 0 0 UPPERCC4 0 0 0 0 0 0 0 0 0 0 0 DON10 0 0 0 0 0 0 0 0 0 0 0 DON11 0 0 0 0 0 0 0 0 0 0 0