DOCSLIB.ORG

Hydrogeology and Water Quality of the West Valley Creek Basin, Chester County, Pennsylvania

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Hydrogeology and Water Quality of the West Valley Creek Basin, Chester County, Pennsylvania Hydrogeology and Water Quality of the West Valley Creek Basin, Chester County, Pennsylvania By Lisa A Senior, Ronald A. Sloto, and Andrew G. Reif U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 94-4137 Prepared in cooperation with the CHESTER COUNTY WATER RESOURCES AUTHORITY Lemoyne, Pennsylvania 1997 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director For additional information Copies of this report can be write to: purchased from: District Chief U.S. Geological Survey U. S. Geological Survey Branch of Information Services 840 Market Street Box 25286 Lemoyne, Pennsylvania 17043-1586 Denver, Colorado 80225-0286 CONTENTS Page Abstract................................................................................... 1 Introduction ...............................................................................3 Purpose and scope .................................................................... 3 Description of the study area ........................................................... 4 Well-numbering system................................................................ 7 Previous investigations................................................................ 7 Acknowledgments.................................................................... 8 Hydrogeology..............................................................................8 Geology ............................................................................. 8 Carbonate rocks................................................................ 10 Vintage Dolomite ......................................................... 10 Kinzers Formation ........................................................ 10 Ledger Dolomite.......................................................... 10 Elbrook Formation ........................................................ 12 Conestoga Limestone...................................................... 12 Noncarbonate rocks............................................................ 12 Leucocratic and intermediate felsic gneiss .................................... 12 Chickies Quartzite ........................................................ 12 Antietem Quartzite and Harpers Phyllite..................................... 12 Octoraro Phyllite.......................................................... 13 Wissahickon Formation.................................................... 13 Peters Creek Schist........................................................ 13 Hydrology.......................................................................... 13 Ground water.................................................................. 13 Water-bearing zones....................................................... 15 Aquifer and well characteristics............................................. 16 Hydraulic conductivity............................................... 16 Specific yield........................................................ 18 Specific capacity and well yield........................................ 18 Water levels .............................................................. 20 Depth to water ...................................................... 20 Fluctuations......................................................... 20 Regional flow............................................................. 26 Surface water .................................................................. 30 Ground-water/surf ace-water relations ............................................ 33 Water budget .................................................................. 40 Water use ................................................................ 40 Basin budget ............................................................. 42 Recharge................................................................. 45 Water quality..............................................................................46 Ground water ....................................................................... 49 CONTENTS Continued Page Water quality Continued Physical properties and field-determined constituents............................... 49 Major ions and constituents...................................................... 51 Metals and other trace constituents ............................................... 58 Radionuclides.................................................................. 60 Organic compounds ............................................................ 62 Volatile organic compounds ................................................ 62 Semivolatile organic compounds............................................ 63 Pesticides ................................................................ 64 Other organic compounds.................................................. 64 Surface water........................................................................ 65 Base flow...................................................................... 65 Physical properties and field-determined constituents ......................... 68 Major ions and constituents ................................................ 75 Metals and other trace constituents.......................................... 86 Streambed sediment............................................................ 90 Benthic invertebrate indices...................................................... 91 Relation between ground-water and surface-water quality ................................ 93 Summary.................................................................................98 References cited ..........................................................................100 ILLUSTRATIONS PLATES [In Pocket] Plate 1. Geology and location of selected wells and springs, West Valley Creek Basin, Chester County, Pennsylvania FIGURES Figures 1-3. Maps showing: 1. Location of the West Valley Creek Basin, Chester County, Pennsylvania ... .4 2. Physiographic provinces, southeastern Pennsylvania.....................5 3. Generalized geology of the West Valley Creek Basin, Pennsylvania, and location of streamflow-measurement stations ..................6 4. Structural cross-sections of Chester Valley, Pennsylvania ......................... 11 5. Water-bearing openings in noncarbonate and carbonate fractured-rock aquifers ..... 14 6. Geophysical logs for well CH-4147 completed in carbonate rock, West Valley Creek Basin, Pennsylvania.................................................... 17 7. Map showing location of observation wells and precipitation gages, West Valley Creek Basin, Pennsylvania ..............................................21 IV ILLUSTRATIONS-Continued Page Figures 8-10. Graphs showing: 8. Water-level fluctuations in observation wells completed in carbonate and noncarbonate rocks, West Valley Creek Basin, Pennsylvania, January 1990 - January 1992 ....................................22 9. Relation between precipitation and the water levels measured in well CH-249, West Valley Creek Basin, Pennsylvania, 1990-91...........23 10. Precipitation and water levels in well CH-3916, West Valley Creek Basin, Pennsylvania, 1990-91 .........................................24 11. Hydrograph of well CH-2738 and daily precipitation, March 10-April 6,1992, West Valley Creek Basin, Pennsylvania ...................................25 12-13. Maps showing: 12. Generalized regional ground-water flow directions, West Valley Creek Basin, Pennsylvania .....................................27 13. Altitude and configuration of the water-table determined from water levels measured May-June 1984, and in the fall of 1983,1987,1990, and 1992, West Valley Creek Basin, Pennsylvania .................28 14-17. Graphs showing: 14. Daily mean discharge at streamflow-measurement stations 01480887, [Westl Valley Creek at Ravine Road near Downingtown, and 01480870, East Branch Brandywine Creek below Downingtown, Pennsylvania, 1990-91 .........................................31 15. Instantaneous discharge at 15-minute intervals at streamflow- measurement stations 01480887, [Westl Valley Creek at Ravine Road near Downingtown, and 01480870, East Branch Brandywine Creek below Downingtown, Pennsylvania, October and December, 1990 ...................................32 16. Base flow and streamflow, at streamflow-measurement station 01480887, [Westl Valley Creek at Ravine Road near Downingtown, Pennsylvania, 1990-91 .........................................33 17. Base flow at streamflow-measurement station 01480887, [Westl Valley Creek at Ravine Road near Downingtown and ground-water levels in a well (CH-249) completed in carbonate rocks, West Valley Creek Basin, Pennsylvania, 1990-91..............................35 18. Map showing location of discharge-measurement sites (October 1990 and 1991) and reconnaissance water-quality-measurement sites (August 1990), West Valley Creek Basin, Pennsylvania ...................................37 19-21. Graphs showing: 19. Base flow and exported sewer flow for the West Valley Creek Basin, Pennsylvania, 1990-91 .........................................45 20. Relation between concentrations of sodium and chloride in ground water in the West Valley Creek Basin, Pennsylvania ...............54 21. Distribution of concentrations of nitrite plus nitrate as nitrogen in ground water in the West Valley Creek Basin, Pennsylvania, grouped by lithology: 1) gneiss and quartzite; 2) carbonate rock; 3) phyllite and schist ..........................................56 ILLUSTRATIONS Continued Page Figures 22. Piper diagrams
Load more

Recommended publications
  • Lancaster County Geology
    LancasterLancaster CountyCounty GeologyGeology gfgh µ OverOver TopographicTopographic ReliefRelief Om Miles Í897 0 10 hg Lebanon County Adamstown ¦¨§76 ! Berks County Oha ! Oo Denver ab322 Ephrata Csc Í501 ! Í72 TRh 272 TRn Oco Lititz Í ! Akron Elizabethtown Manheim ! Dauphin County! ! TRhc Cr TRs c Os Rn ! T Terre Hill TRg Trd 322 772 ab 10 Í 222 625 Í ab Í897 Í Í283 Ohm Í230 Oan Í241 East New Holland Oe 722 Petersburg Í Cbs ! Mount Joy ! ! Czc Cch Í23 Cm gga fl R 743 T Í Csb gg pg ggd Í441 Ck Cl 772 72 Í 23 Í ! Í Ca Marietta Ch Lancaster Mountville ! 340 ! Í Columbia 30 ! ! ba Í462 Í462 ab30 Í999 Millersville Ccc Strasburg ! ! Cv Í741 Í741 Í272 41 Í County Chester 896 222 Í gn Christiana ba mg ! oct Cah Í372 S u sq u e h a n n a R iv e r Y o rk C o u n ty gqm LEGEND COUNTY BOUNDARIES Í324 Source: Lancaster County GIS, Copyright (c) 2019 MAJOR ROADS This map to be used for reference or illustrative purposes only. This map FAULT is not a legally recorded plan, survey, or engineering schematic Quarryville and it is not intended to be used as such. For complete disclaimer see: RIVERS AND STREAMS ! http://www.co.lancaster.pa.us/gisdisclaimer DIKE wc ORDOVICIAN Í472 Oan, ANNVILLE FORMATION LIMESTONE TRIASSIC 372 Oco, COCALICO FORMATION DARK GRAY SHALE TRfl, LIMESTONE FANGLOMERATE Í TRg, GETTYSBURG FORMATION SHALE-SANDSTONE Oe, EPLER FORMATION LIMESTONE TRh, HAMMER CREEK FORMATION SANDSTONE-SHALE Oha, ANNVILLE, HERSHEY, AND MYERSTOWN FORMATION TRhc, HAMMER CREEK QUARTZ-CONGLOMERATE Ohm, HERSHEY AND MYERSTOWN FORMATION LIMESTONE 272 TRn, NEW
    [Show full text]
  • USNMP-76 2806 1929.Pdf
    NEW LOWER AND MIDDLE CAJ^IBRIAN CRUSTACEA By Charles E, Resser Associate Curator of Stratigraphic Paleontology INTRODUCTION Among the numerous Cambrian fossils that have been accumulating in the United States National Museum during the last 15 years, there are many undescribed species and some of the specimens are remarkable for the preservation of thin tests or of soft body parts. In order to stimulate further search for the rarer fossils, and par- ticularly for preservations of the softer parts of animals or of delicate plant tissues, it is planned to publish more or less related groups of these animals from time to time. Accordingly, in this paper I have assembled a group of species that centers mainly around the pre- viously described genus Tuzoia, but which also includes several unre- lated forms that were secured from the same localities as the others. This paper thus adds several new species preserving more than ordinarily thin tests of Crustacea and a few with the still softer fleshy parts. Some are from the well known Burgess shale that has already furnished so many interesting animals and plants, but other formations, some of which have not previously been known to yield such fossils, are also represented. This paper also contains information of interest aside from that naturally attaching to any description of the softer parts of such ancient animals, by presenting certain important stratigraphic facts in addition to further data regarding the geographic distribution and origin of the faunas to which these species belong. Acknowledgment.—In the preparation of this paper I was kindly assisted by Dr.
    [Show full text]
  • Gettysburg National Military Park & Eisenhower National Historic Site
    National Park Service U.S. Department of the Interior Natural Resource Program Center Gettysburg National Military Park & Eisenhower National Historic Site Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2009/083 THIS PAGE: North Carolina State Monument (NPS Photo) ON THE COVER: Gettysburg NMP, looking toward Cemetery Ridge Cover photo by Bill Dowling, courtesy of the Gettysburg Foundation Gettysburg National Military Park and Eisenhower National Historic Site Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2009/083 Geologic Resources Division Natural Resource Program Center P.O. Box 25287 Denver, Colorado 80225 March 2009 U.S. Department of the Interior National Park Service Natural Resource Program Center Denver, Colorado The Natural Resource Publication series addresses natural resource topics that are of interest and applicability to a broad readership in the National Park Service and to others in the management of natural resources, including the scientific community, the public, and the NPS conservation and environmental constituencies. Manuscripts are peer-reviewed to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and is designed and published in a professional manner. Natural Resource Reports are the designated medium for disseminating high priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. Examples of the diverse array of reports published in this series include vital signs monitoring plans; "how to" resource management papers; proceedings of resource management workshops or conferences; annual reports of resource programs or divisions of the Natural Resource Program Center; resource action plans; fact sheets; and regularly-published newsletters.
    [Show full text]
  • Carbonate Rocks of Cambrian and Ordovician Age in the Lancaster Quadrangle Pennsylvania
    Carbonate Rocks of Cambrian and Ordovician Age in the Lancaster Quadrangle Pennsylvania By HAROLD MEISLER and ALBERT E. BECHER CONTRIBUTIONS TO STRATIGRAPHY GEOLOGICAL SURVEY BULLETIN 1254-G Prepared in cooperation with the Pennsylvania Geological Survey Department of Internal Affairs Commonwealth of Pennsylvania UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director U.S. GOVERNMENT PRINTING OFFICE WASHINGTON : 1968 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 10 cents CONTENTS Page Abstract-____-___- _._-_-._____-____.-.____,-__._______-^___-----^-_ Gl Introduction._______-_______-__-_-_---______-_-_ ____---__--__--__ 1 Cambrian System.________________________________________________ 5 Vintage, Kinzers, and Ledger Formations__-^___^_-___-_--____-___ 5 Zooks Corner Formation______________________________________ 6 Conococheague Group.___-____-_-__-___- -______--___-_--_-___ 7 Buffalo Springs Formation_____-_-_---_---_-----_---_----- 9 Snitz Creek Formation.____________________________________ 9 Millbach Formation____-_-________^.__.___________________ 9 Richland Formation._______________________________________ 10 Ordovician System.-_______________________________________________ 10 Conestoga Limestone___---__-____-____-_-_-_-__--_-__---__-__ 10 Beekmantown Group.______-_--___---__.--_____-_-_____________ 11 Stonehenge Formation.____________________________________ 11 Epler Formation._________________________________________ 11 Ontelaunee Formation___-_-_-______-_.___^-__---__---__--__ 12 Annville Limestone.______________--___.-___--___--___----_---_ 13 Myerstown Limestone._______________________________________ 13 References cited.__________________________________________________ 13 ILLUSTRATIONS Page FIGURE 1. Map showing the location of the Lancaster quadrangle and general physiography of southeastern Pennsylvania. _______ G2 2.
    [Show full text]
  • PCPG Newsletter Communicating Key Information & Concerns to Geologists and Environmental Professionals Issue 3 / 2017
    PCPG Newsletter Communicating Key Information & Concerns to Geologists and Environmental Professionals Issue 3 / 2017 INSIDE THIS ISSUE... President’s Message ............................................................................................................... 1 Field Trip to Limestone Mine ................................................................................................. 2 BOARD OF DIRECTORS Member Spotlight ................................................................................................................... 4 President GAC Update ............................................................................................................................ 7 Dan Billman, P.G., C.P.G. Billman Geologic Consultants, LLC [email protected] President Elect MESSAGE FROM THE PRESIDENT Martin F. Helmke, PhD, P.G. West Chester University of Pennsylvania [email protected] Welcome to Fall!! Looking into my backyard, I see Immediate Past President the leaves of the birch trees are starting to turn color. Gary Kribbs, P.G. AEON Geoscience, Inc. Typically, Fall always seems to feel like the beginning of [email protected] a new year. Not a calendar year, obviously, but a school Permanent Director (1936-2016) year. I guess that is programmed into us, each of our first Richard E. Wright, P.G. R. E. Wright, P.G., LLC 18 to 22 years on the planet. As Professional Geologists, we are on a similar schedule. Every second year, in the Board Members Vincent Carbone, P.G., C.P.G. Fall, we need to re-register our license.
    [Show full text]
  • Description of the Fairfield and Gettysburg Quadrangles
    DESCRIPTION OF THE FAIRFIELD AND GETTYSBURG QUADRANGLES By George W. Stose and F. Bascom 1 INTRODUCTION The Appalachian Highlands include three well-marked Ridge comprises many minor ridges, which, under local names, longitudinal subdivisions, each characterized by a general extend from southeastern New York to northern Georgia. LOCATION AND AREA similarity of sedimentary deposits, geologic structure, and Chief among these are the Highlands of southeastern New The Fairfield and Gettysburg quadrangles are in the south- topography. The western subdivision includes the Appalach­ York and New Jersey, South Mountain in Pennsylvania, the central part of Pennsylvania, between parallels 39° 45' and ian Plateaus; the middle subdivision is the Appalachian Blue Ridge and Catoctin Mountain in Maryland and Virginia, 40° and meridians 77° and 77° 30', and together contain about Valley and Pvidges province; the eastern subdivision includes the Great Smoky Mountains in Tennessee and North Carolina, 458 square miles. They embrace the larger part of Adams the Blue Ridge and Piedmont provinces. Topographically the and the Blue Ridge in Georgia. County, the east side of Franklin County, and the south corner Blue Ridge and Piedmont provinces are distinct, but geologi­ The Piedmont province is a wide belt of upland southeast of of Cumberland County. The southern border of the area is cally they are so closely allied that they may be better treated the Blue Ridge province. It descends gently southeastward within 2 miles of the Maryland State boundary. (See fig. 1.) as a unit. These three subdivisions are well defined from and grades into the Coastal Plain, which borders the Atlantic Alabama to southern New York, and the following description Ocean.
    [Show full text]
  • New Palaeoscolecidan Worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale
    New palaeoscolecidan worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale SIMON CONWAY MORRIS and JOHN S. PEEL Conway Morris, S. and Peel, J.S. 2010. New palaeoscolecidan worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica 55 (1): 141–156. Palaeoscolecidan worms are an important component of many Lower Palaeozoic marine assemblages, with notable oc− currences in a number of Burgess Shale−type Fossil−Lagerstätten. In addition to material from the lower Cambrian Kinzers Formation and Latham Shale, we also describe two new palaeoscolecidan taxa from the lower Cambrian Sirius Passet Fossil−Lagerstätte of North Greenland: Chalazoscolex pharkus gen. et sp. nov and Xystoscolex boreogyrus gen. et sp. nov. These palaeoscolecidans appear to be the oldest known (Cambrian Series 2, Stage 3) soft−bodied examples, being somewhat older than the diverse assemblages from the Chengjiang Fossil−Lagerstätte of China. In the Sirius Passet taxa the body is composed of a spinose introvert (or proboscis), trunk with ornamentation that includes regions bearing cuticu− lar ridges and sclerites, and a caudal zone with prominent circles of sclerites. The taxa are evidently quite closely related; generic differentiation is based on degree of trunk ornamentation, details of introvert structure and nature of the caudal re− gion. The worms were probably infaunal or semi−epifaunal; gut contents suggest that at least X. boreogyrus may have preyed on the arthropod Isoxys. Comparison with other palaeoscolecidans is relatively straightforward in terms of compa− rable examples in other Burgess Shale−type occurrences, but is much more tenuous with respect to the important record of isolated sclerites.
    [Show full text]
  • The Endemic Radiodonts of the Cambrian Stage 4 Guanshan Biota of South China
    Editors' choice The endemic radiodonts of the Cambrian Stage 4 Guanshan Biota of South China DE-GUANG JIAO, STEPHEN PATES, RUDY LEROSEY-AUBRIL, JAVIER ORTEGA-HERNÁNDEZ, JIE YANG, TIAN LAN, and XI-GUANG ZHANG Jiao, D.-G., Pates, S., Lerosey-Aubril, R., Ortega-Hernández, J., Yang, J., Lan, T., and Zhang, X.-G. 2021. The endemic radiodionts of the Cambrian Stage 4 Guanshan Biota of South China. Acta Palaeontologica Polonica 66 (2): 255–274. The Guanshan Biota (South China, Cambrian, Stage 4) contains a diverse assemblage of biomineralizing and non-biomin- eralizing animals. Sitting temporally between the Stage 3 Chengjiang and Wuliuan Kaili Biotas, the Guanshan Biota con- tains numerous fossil organisms that are exclusive to this exceptional deposit. The Guanshan Konservat-Lagerstätte is also unusual amongst Cambrian strata that preserve non-biomineralized material, as it was deposited in a relatively shallow water setting. In this contribution we double the diversity of radiodonts known from the Guanshan Biota from two to four, and describe the second species of Paranomalocaris. In addition, we report the first tamisiocaridid from South China, and confirm the presence of a tetraradial oral cone bearing small and large plates in “Anomalocaris” kunmingensis, the most abundant radiodont from the deposit. All four radiodont species, and three genera, are apparently endemic to the Guanshan Biota. When considered in the wider context of geographically and temporally comparable radiodont faunas, endemism in Guanshan radiodonts is most likely a consequence of the shallower and more proximal environment in which they lived. The strong coupling of free-swimming radiodonts and benthic communities underlines the complex relationship between the palaeobiogeographic and environmental distributions of prey and predators.
    [Show full text]
  • New Suspension-Feeding Radiodont Suggests Evolution of Microplanktivory in Cambrian Macronekton
    ARTICLE DOI: 10.1038/s41467-018-06229-7 OPEN New suspension-feeding radiodont suggests evolution of microplanktivory in Cambrian macronekton Rudy Lerosey-Aubril 1 & Stephen Pates 2,3 The rapid diversification of metazoans and their organisation in modern-style marine eco- systems during the Cambrian profoundly transformed the biosphere. What initially sparked 1234567890():,; this Cambrian explosion remains passionately debated, but the establishment of a coupling between pelagic and benthic realms, a key characteristic of modern-day oceans, might represent a primary ecological cause. By allowing the transfer of biomass and energy from the euphotic zone—the locus of primary production—to the sea floor, this biological pump would have boosted diversification within the emerging metazoan-dominated benthic communities. However, little is known about Cambrian pelagic organisms and their trophic interactions. Here we describe a filter-feeding Cambrian radiodont exhibiting morphological characters that likely enabled the capture of microplankton-sized particles, including large phyto- plankton. This description of a large free-swimming suspension-feeder potentially engaged in primary consumption suggests a more direct involvement of nekton in the establishment of an oceanic pelagic-benthic coupling in the Cambrian. 1 Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia. 2 Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK. 3 Institute of
    [Show full text]
  • Valley Forge National Historical Park Geologic Resources Inventory Report
    National Park Service U.S. Department of the Interior Natural Resource Program Center Valley Forge National Historical Park Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2010/236 THIS PAGE: Reconstruction of a hut built by soldiers of Washington’s Continental Army to survive the winter of 1777-1778. Copyrighted image by M.J. Ticcino for National Park Service, courtesy Kristina Heister (Valley Forge National Historical Park) ON THE COVER: The Grand Parade ground of Valley Forge National Park, view from the Huntington Camp. Mount Joy rises in the background. National Park Service photo- graph by Megan Carfioli, courtesy Amy Ruhe and Kris- tina Heister (Valley Forge National Historical Park). Valley Forge National Historical Park Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2010/236 Geologic Resources Division Natural Resource Program Center P.O. Box 25287 Denver, Colorado 80225 September 2010 U.S. Department of the Interior National Park Service Natural Resource Program Center Ft. Collins, Colorado The National Park Service, Natural Resource Program Center publishes a range of reports that address natural resource topics of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner.
    [Show full text]
  • Index to the Geologic Names of North America
    Index to the Geologic Names of North America GEOLOGICAL SURVEY BULLETIN 1056-B Index to the Geologic Names of North America By DRUID WILSON, GRACE C. KEROHER, and BLANCHE E. HANSEN GEOLOGIC NAMES OF NORTH AMERICA GEOLOGICAL SURVEY BULLETIN 10S6-B Geologic names arranged by age and by area containing type locality. Includes names in Greenland, the West Indies, the Pacific Island possessions of the United States, and the Trust Territory of the Pacific Islands UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1959 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.G. - Price 60 cents (paper cover) CONTENTS Page Major stratigraphic and time divisions in use by the U.S. Geological Survey._ iv Introduction______________________________________ 407 Acknowledgments. _--__ _______ _________________________________ 410 Bibliography________________________________________________ 410 Symbols___________________________________ 413 Geologic time and time-stratigraphic (time-rock) units________________ 415 Time terms of nongeographic origin_______________________-______ 415 Cenozoic_________________________________________________ 415 Pleistocene (glacial)______________________________________ 415 Cenozoic (marine)_______________________________________ 418 Eastern North America_______________________________ 418 Western North America__-__-_____----------__-----____ 419 Cenozoic (continental)___________________________________
    [Show full text]
  • Exploring Abnormal Cambrian-Aged Trilobites in the Smithsonian Collection
    Exploring abnormal Cambrian-aged trilobites in the Smithsonian collection Russell D.C. Bicknell1 and Stephen Pates2 1 Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia 2 Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Boston, United States of America ABSTRACT Biomineralised trilobite exoskeletons provide a 250 million year record of abnormalities in one of the most diverse arthropod groups in history. One type of abnormality— repaired injuries—have allowed palaeobiologists to document records of Paleozoic predation, accidental damage, and complications in moulting experienced by the group. Although Cambrian trilobite injuries are fairly well documented, the illustration of new injured specimens will produce a more complete understanding of Cambrian prey items. To align with this perspective, nine new abnormal specimens displaying healed injuries from the Smithsonian National Museum of Natural History collection are documented. The injury pattern conforms to the suggestion of lateralised prey defence or predator preference, but it is highlighted that the root cause for such patterns is obscured by the lumping of data across different palaeoecological and environmental conditions. Further studies of Cambrian trilobites with injuries represent a key direction for uncovering evidence for the Cambrian escalation event. Subjects Evolutionary Studies, Paleontology Keywords Trilobites, Abnormalities, Cambrian Explosion, Durophagy, Escalation, Healed injuries Submitted 21 October 2019 Accepted 23 December 2019 INTRODUCTION Published 3 February 2020 Corresponding author The Cambrian Explosion—a rapid and stunning increase in animal diversity and Russell D.C. Bicknell, disparity during the earliest Paleozoic, over 500 million years ago—likely resulted from a [email protected], combination of biological, ecological, and environmental factors (Smith & Harper, 2013; [email protected] Zhang et al., 2014; Bicknell & Paterson, 2018).
    [Show full text]