GGEEOOLLOOGGIICCAALL SSOOCCIIEETTYY OOFF AAMMEERRIICCAA NNOORRTTHHEEAASSTT SSEECCTTIIOONN 47TH Annual Meeting, Hartford, Connecticut March 17‐20, 2012 GGuuiiddeebbooookk ffoorr FFiieellddttrrippss iinn CCoonnnneeccttiiccuutt aanndd MMaassssaacchhuusseettttss State Geological and Natural History Survey of Connecticut Guidebook Number 9 The Honorable Dannel P. Malloy, Governor State of Connecticut Daniel C. Esty, Commissioner Connecticut Department of Energy and Environmental Protection Editor Margaret A. Thomas, CPG Connecticut State Geologist Published by State Geological and Natural History Survey of Connecticut Department of Energy and Environmental Protection in cooperation with The Geological Society of Connecticut ISBN 978‐0‐942081‐19‐0 Publication Availability Department of Energy and Environmental Protection Store 79 Elm Street, Hartford, CT 06106‐5127 (860) 424‐3555 www.depstore.com GEOLOGICAL SOCIETY OF AMERICA John W. Geissman, President NORTHEAST SECTION, GEOLOGICAL SOCIETY OF AMERICA Robert P. Wintsch, Chair William Cox, GSA Meeting Liaison 2012 CONFERENCE ORGANIZATION GENERAL CHAIR Jean Crespi Center for Integrative Geosciences University of Connecticut Storrs, Connecticut TECHNICAL PROGRAM Mark Evans Michael Wizevich Department of Physics and Earth Science Central Connecticut State University New Britain, Connecticut FIELDTRIPS Margaret A. Thomas Connecticut Geological Survey Department of Energy and Environmental Protection Guidebook cover photo credits: Teresa Gagnon, Patrick Getty, Robert Wintsch, Gregory Walsh, Robert Thorson, Peter Drzewiecki Guidebook for Fieldtrips in Connecticut and Massachusetts: Northeast Section Geological Society of America Meeting 2012 State Geological and Natural History Survey of Connecticut, Guidebook Number 9 TABLE OF CONTENTS WERE EARLY JURASSIC DINOSAURS GREGARIOUS? A1­A18 REEXAMINING THE EVIDENCE FROM DINOSAUR FOOTPRINT RESERVATION IN HOLYOKE, MASSACHUSETTS PATRICK R. GETTY, AARON JUDGE, JAYME CSONKA, ANDREW M. BUSH THE HARTFORD BASIN FROM HANGING HILLS TO THE SOUND B1­B30 BRIAN SKINNER, LEO HICKEY, ANTHONY PHILPOTTS, JAY AGUE TEMPERATURE­TIME PATHS TIE THE TALES OF TWO FORELANDS: C1­C32 THE NARRAGANSETT AND HARTFORD BASINS ROBERT P. WINTSCH, MICHAEL J. KUNK, JOHN N. ALEINIKOFF, MARY RODEN­TICE, M.R. STOKES, E.M. STEWART, R. STEINEN UNRAVELING ALLEGHANIAN OROGENESIS IN SOUTHERN CONNECTICUT: D1­D16 THE HISTORY OF THE LYME DOME GREGORY J. WALSH, JOHN N. ALEINIKOFF, ROBERT P. WINTSCH THE GEOLOGY OF WALDEN POND E1­E9 ROBERT THORSON ANCIENT LAKE AND RIVER ENVIRONMENTS: A CORE AND FIELD F1­F35 WORKSHOP ON THE JURASSIC PORTLAND FORMATION PETER A. DRZEWIECKI, ELIZABETH H. GIERLOWSKI­KORDESCH, RANDOLPH P. STEINEN, DAVID FINKELSTEIN Guidebook for Fieldtrips in Connecticut and Massachusetts: Northeast Section Geological Society of America Meeting 2012 State Geological and Natural History Survey of Connecticut, Guidebook Number 9 GETTY, JUDGE, CSONKA, AND BUSH WERE EARLY JURASSIC DINOSAURS GREGARIOUS? REEXAMINING THE EVIDENCE FROM DINOSAUR FOOTPRINT RESERVATION IN HOLYOKE, MASSACHUSETTS Patrick R. Getty, Center for Integrative Geosciences, University of Connecticut, Storrs, CT 06269 Aaron Judge, Dept. of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA Jayme Csonka, Center for Integrative Geosciences, University of Connecticut, Storrs, CT Andrew M. Bush, Center for Integrative Geosciences; Dept. of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT INTRODUCTION Our understanding of dinosaurs has changed radically since the “Dinosaur Renaissance” of the 1970s (see Bakker, 1975). Before that time, these animals were considered evolutionary dead-ends which gave way to the more advanced mammals after the end-Cretaceous extinction event. However, as Bakker pointed out in his analysis of such disparate lines of evidence as bone histology and predator-prey ratios, many dinosaurs appear to have been much more like the mammals in terms of their metabolism than had been previously thought. At the same time, our view of the social lives of dinosaurs also changed. No longer were they viewed as solitary animals, rather, many became viewed as social or gregarious animals. But what evidence is there that we should change our view of dinosaurs and their social lives? First, we must more define what it means to be gregarious. Gregariousness is the tendency of some animals to gather into structured social groups for a common purpose, such as greater defense against predators, increased access to food, increased breeding efficiency, protection and rearing of young, or increased migration efficiency (Currie and Eberth, 2010). As Ostrom (1972) pointed out, not all natural accumulations of animals constitute a gregarious assemblage. For example, frogs in a pond are not gregarious because the pond dictates where the animals live. Typically, for living animals, the social interactions inherent in gregarious behavior are obvious. For extinct animals, however, gregariousness can only be inferred from their fossil record. Where body fossils (e.g., bones and teeth) are abundant, gregarious behavior is often inferred from deposits consisting of a single taxon, called monospecific bone beds (Horner, 2002). Unfortunately, many regions, such as the Late Triassic- through Early Jurassic-aged Hartford Basin of Connecticut and Massachusetts (Fig. 1) are nearly devoid of body fossils due to the effects of soil and groundwater chemistry (McDonald, 1992, 1995; Getty and Bush, 2011). In places with a depauperate body fossil record, trace fossils—such as footprints and trackways— may be used as a proxy for skeletal material and can be used to infer gregarious behavior. Indeed, trace fossils may be better indicators of gregariousness than body fossils since they are sedimentary structures that reflect the behavior of the living animals. In contrast, bone beds may result from other factors, including serial predation (predators killing their preferred prey species in the same location over time) and postmortem sorting and accumulation by biological or sedimentological processes (Rogers and Kidwell, 2007). Gregariousness may be inferred from trace fossils by a suite of characteristics (Lockley, 1991). Among the most obvious of these is trackway parallelism, since herding animals will leave nearly parallel Guidebook for Fieldtrips in Connecticut and Massachusetts: Northeast Section Geological Society of America Meeting 2012 State Geological and Natural History Survey of Connecticut, Guidebook Number 9 A1 GETTY, JUDGE, CSONKA, AND BUSH trackways as the herd moves from place to place. Indeed, Edward Hitchcock, in his seminal studies of fossilized footprints, considered parallel trackways as evidence of gregariousness as early as 1836 (see historical account, below). However, parallel trackwa ys also may result from animals walking next to Figure 1. Location and geologic context of Dinosaur Footprint Reservation (DFR). A: Bedrock geology of the northern portion of the Hartford Basin. The star incates the location of DFR within the basin. B: Simplified stratigraphic column of Hartford Basin rocks showing the position of DFR immediately above the Granby Tuff. C: Google Earth image of the land surrounding DFR. Note the position of DFR immediately to the east of U.S. Rte. 5 and additional outcrops along the west bank of the Connecticut River (labeled “beds by river.” D: Oblique view of the “Ostrom bed” at DFR. E: View to the south of beds cropping out along the Connecticut River. These beds, which are not part of the reservation, also preserve dinosaur tracks. Panels A and B modified from Collette et al. (2011) and reproduced with permission of Atlantic Geology. Guidebook for Fieldtrips in Connecticut and Massachusetts: Northeast Section Geological Society of America Meeting 2012 State Geological and Natural History Survey of Connecticut, Guidebook Number 9 A2 GETTY, JUDGE, CSONKA, AND BUSH a physical barrier, such as a shoreline (e.g., Ostrom 1972; Lockley, 1991). Since physical barriers can create the illusion of group behavior by funneling animals along a predetermined path, other criteria must also be considered. These other criteria include the constant spacing between both straight and turning trackways that results from members of a group walking next to each other without colliding (Currie, 1983). Additionally, similar speeds calculated from trackways can also be used as evidence for group behavior since the animals will tend to move at the roughly the same velocity in order to remain in a coherent group (Martin, 2006, p. 433). Finally, because track depth will vary with time (tracks made in wet mud will be deeper than those made in the same substrate after it has dried in the sun a while), depth may be used to infer or reject hypothesized gregariousness (Lockley, 1991). Thus, Getty (2005, p. 173) rejected the hypothesis that two trackways of carnivorous dinosaurs were made by a group because the nearly overlapping and subparallel trackways had significantly different depths and preservational quality. Based on both body and trace fossil evidence, examples of gregariousness are now known in many groups of herbivorous dinosaurs, including ankylosaurs (e.g., McCrea and Currie, 1998; McCrea, 2000), ceratopsians (e.g., Currie and Dodson, 1984; Lockley and Hunt, 1995; Ryan et al., 2001; Qi et al., 2007), ornithopods (e.g., Cotton et al., 1998; Scherzer and Varricchio, 2010), and sauropodomorphs (e.g., von Huene, 1928; Bird, 1944; Lockley et al., 2002; Castanera et al., 2011). Additionally,