DOCSLIB.ORG

Fossils of Dresbachian and Franconian (Cambrian) Age from the Subsurface of West-Central Indiana

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

- Fossils of Dresbachian and Franconian (Cambrian) Age from the Subsurface of West-Central Indiana By ALLISON R. PALMER DEPARTMENT OF NATURAL RESOURCES GEOLOGICAL SURVEY SPECIAL REPORT 29 PRINTED BY AUTHORITY OF THE STATE OF INDIANA BLOOMINGTON, INDIANA: 1982 STATE OF INDIANA r Robert D. Orr, Governor DEPARTMENT OF NATURAL RESOURCES James M. Ridenour, Director GEOLOGICAL SURVEY John B. Patton, State Geologist For sale by Geological Survey, Bloomington, Ind. 47405 Price $2.50 Contents Page r Abstract .... .1 Introduction .. .1 Acknowledgments .1 Stratigraphy ... .2 Paleontology . .3 Faunas of Franconian age .3 Faunas of Dresbachian age .7 Literature cited 11 Illustrations [Plates follow Literature Cited] Page Plate 1 Trilobites of Franconian age 2 Trilobites and gastropods of Dresbachian age Figure 1 Map of the eastern midcontinent region showing the general position of the lllinois Basin, subsurface datum points, and depositional facies of beds of the Crepicephalus Zone (middle Dresbachian age) ................. 2 2 Stratigraphic column showing the locations of paleontologic control (F) and the suggested stratigraphic nomenclature for the fossiliferous Cambrian part of Vermillion County well FMC No. WD-1 .................. 3 - Fossils of Dresbachian and Franconian (Cambrian) Age from the Subsurface of West-Central Indiana By ALLISON R. PALMER Abstract additional specimens not noted in my earlier Three fossiliferous levels in FMC No. WD-1, a report for Becker. Then publication of well in Vermillion County, Ind., have yielded descriptions of Franconian trilobites from Cambrian fossils. The highest level, in the southeastern Missouri (Kurtz, 1975) provided Davis Formation between depths of 4,497 a basis for reidentification of the trilobites and 4,546 feet, contains 17 distinct layers from the Davis Formation in the Vermillion with trilobites of the Elvinia Zone of early County well. The faunal identifications Franconian age. A single horizon, in an upper presented here reflect the new discoveries and oolite member of the Eau Claire Formation at the updating of identifications made since a depth of 4,698 feet, contains trilobites, completion of the 1970 report. gastropods, and other ·fossils of the Crepi­ Identifiable fossils, mostly trilobites, are cephalus Zone of middle Dresbachian age. present at three distinct levels in the Two lower horizons, in green shales of the Vermillion County well (fig. 2). The richest Eau Claire Formation at depths of 5,061 and interval is within the Davis Formation 5,083 feet, contain trilobites of the Cedaria between 4,497 and 4,546 feet. Seventeen silty Zone of early Dresbachian age. Characteristic to fine-sandy limestone layers in this 49-foot trilobites and gastropods are illustrated and interval yielded trilobites characteristic of the discussed. early Franconian Elvinia Zone (pI. 1). A single The upper oolite member is considered to collection from oolitic limestone at a depth of be a possible extension of part of the 4,698 feet yielded trilobites and other fossils Bonneterre Formation of Missouri. If this is (pI. 2, figs. 1-16) that represent the correct, the paleogeography of this interval in Crepicephalus Zone of middle Dresbachian the eastern midcontinent region suggests an age. Green to red micaceous shales at depths early presence of, or precursory conditions of 5,061 and 5,083 feet yielded trilobites (pI. for, the Illinois Basin. 2, figs. 17, 18) that represent a fauna of the Cedaria Zone of early Dresbachian age. Introduction This report confirms the record of fossils of Acknowledgments Dresbachian and early Franconian (Cambrian) Leroy E. Becker, then of the Indiana age from a deep well (FMC No. WD-l in the Geological Survey, and Alan S. Horowitz, NW1.4 sec. 9, T. 16 N., R. 9 W.) in Vermillion curator of paleontology, Department of County, west-central Indiana (figs. 1 and 2) Geology, Indiana University, sorted through (Becker and others, 1978). Fossils were first the Cambrian cores from Indiana and selected noted in cores 41,4 inches in diameter from the fossiliferous samples that were studied for this well by Becker in 1970 and were sent to this report. The photography was done by me for identification. Those preliminary Robert Eby, using facilities of the Depart­ identifications, made in August 1970, were ment of Earth and Space Sciences, State published in Becker and others (1978). In the University of New York, Stony Brook, N.Y. summer of 1977, I was asked to reexamine Partial funding was provided by NSF grant the faunas from this well and to prepare this EAR7825074. Final typing of the manuscript report. Permission was given for processing was done by Jean Davis of the Geological the samples for whatever could be recovered. Society of America. This resulted in the discovery of some 1 2 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AG - o 200 Miles I I I o 300 Km -----~- MO. EAU CLAIRE \ -.. ~I~ ) FORMATION I I ~r I .J WO-I l:weltfM9 I I . .( uppel: \ \ >()oH.te l i ILLINOIS·;memner ~j -- -- T~~N.- - -­ Figure 1. Map of the eastern midcontinent region showing the general position of the minois Basin, subsurfac datum points, and depositional facies of beds of the Crepicephalus Zone (middle Dresbachian age). Well FM No. WD-l yielded the fossils described in this report. Stratigraphy most part of the Bonneterre Formation i The description of the lithologic succession several areas includes an oolitic interval ( that was assigned to the Eau Claire Formation comparable thickness (Howe and other in the Vermillion County well by Becker and 1972, pI. 1; Kurtz and others, 1975, pI. 1 others (1978) suggests that perhaps an that has also yielded faunas of the Crep alternative stratigraphic nomenclature might cephalu8 Zone (Lochman, 1968). Thereforl be appropriate for this interval. The upper the upper oolitic member of the Eau Claire i 18S-foot unit of the Eau Claire Formation is Indiana is considered to correlate with, an the upper of two distinct oolitic limestone perhaps to be an extension of, the UpPE members within the predominantly shaly and Bonneterre of Missouri. silty dolomitic Eau Claire Formation, and it is Buschbach (1964) described the Lombar this member that yields the faunas of the Dolomite Member of the Eau Claire Forml Crepicephalus Zone. In Missouri, the upper­ tion in northeastern lliinois as a sand PALEONTOLOGY 3 is no precise faunal control on the age of these rocks, the Lombard Dolomite Member D~EpLiH STRATIGRAPHIC FAUNAL DATA AND AGE (FT) NOMENCLATURE INTERPRETATION may also be a tongue of the upper part of the Bonneterre Formation. As better control on the ages and lithologic correlations of r KNOX DOLOMITE Z 4400-+----------1 subsurface units in the eastern midcontinent <t region is developed, the lithostratigraphic Z o nomenclature should be reviewed and revised to reflect more clearly the regional distribu­ DAVIS u 4500 z tion of distinctive bodies of rock. Figure 1 FORMATION Elvinia <t assumes that the correlations discussed above Zone c::: u... are correct and gives some indication of the distribution of lithofacies of probable Crepi­ ? cephalus Zone age in the eastern midconti­ 4600 nent region on the basis of data from upper Grohskopf (1955), Buschbach (1964), Howe and others (1972), Kurtz and others (1975), oolite CrepicephallJs and Becker and others (1978). 4700 member F Zone z The area of probable carbonate sedimenta­ tion of middle Dresbachian age covers the site <t of much of the present Illinois Basin and changes southward into a deeper water 4800 :r: black-shale facies with agnostid trilobites u (Glyptagnostus) typical of ocean-facing sites <t (Grohskopf, 1955; Palmer, 1962). This 4900 OJ suggests that tectonic conditions controlling sedimentation patterns in Cambrian time were EAU CLAIRE en perhaps precursors to the formation of the w illinois Basin. c::: Some comments on the biostratigraphic 5000 o and biogeographic significance of the fossils found in the Vermillion County well are FORMATION F Cedaria presented below. 5100 F Zone Paleontology FAUNAS OF FRANCONIAN AGE A 51-foot interval within the Davis Forma­ Figure 2. Stratigraphic column showing the locations tion, between depths of 4,497 and 4,546 feet of paleontologic control (F) and the suggested stra­ in the Vermillion County well, includes a tigraphic nomenclature for the fossiliferous Cam· brian part of Vermillion County well FMC No. fauna dominated by disarticulated remains of WD-l. Datum is 5 feet above ground level and 647 trilobites, with rare fragments of linguloid feet above sea level. brachiopods. Thirteen species of trilobites, representing 10 genera, are present. Almost all of them represent genera characteristic of the dolomite with rare limestone interbeds. This Elvinia Zone of early Franconian age. The member ranges from 100 to 150 feet in definitive species for biostratigraphic dating thickness, which is not too much less than the are Eluinia roemeri (Shumard), Eluinia granu­ thickness of the Bonneterre equivalent (upper lata Resser, Pterocephalia sanctisabae Roe­ oolite member) in the Vermillion County mer, Bynumina caelata Resser, and Calo­ well. Although Buschbach included other cephalites cf. C. vulgaris Kurtz. The abun­ clastics above this dolomite in the Eau Claire dance of specimens of Calocephalites and the Formation of northeastern Illinois and there presence of Bynumina caeiata, both previous­ 4 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AG ly known only from the Davis Formation of material will be required to adequatel: Missouri (Kurtz, 1975), suggest similar condi­ characterize the new taxa that they rna: tions of deposition for the Davis Formation in represent. - Indiana and Missouri and emphasize the general faunal similarity of the two regions. Occurrence: Vermillion County well FMC N( Most other elements in the fauna are found in WD-1 at depths of 4,518, 4,518.5, 4,52( the Elvinia Zone throughout the central and 4,520.8, 4,530, 4,531, 4,531.5, 4,533, an, western United States.
Recommended publications
  • On the Continuity of Background and Mass Extinction

    On the Continuity of Background and Mass Extinction

    Paleobiology, 29(4), 2003, pp. 455±467 On the continuity of background and mass extinction Steve C. Wang Abstract.ÐDo mass extinctions grade continuously into the background extinctions occurring throughout the history of life, or are they a fundamentally distinct phenomenon that cannot be explained by processes responsible for background extinction? Various criteria have been proposed for addressing this question, including approaches based on physical mechanisms, ecological se- lectivity, and statistical characterizations of extinction intensities. Here I propose a framework de®ning three types of continuity of mass and background extinc- tionsÐcontinuity of cause, continuity of effect, and continuity of magnitude. I test the third type of continuity with a statistical method based on kernel density estimation. Previous statistical ap- proaches typically have examined quantitative characteristics of mass extinctions (such as metrics of extinction intensity) and compared them with the distribution of such characteristics associated with background extinctions. If mass extinctions are outliers, or are separated by a gap from back- ground extinctions, the distinctness of mass extinctions is supported. In this paper I apply Silverman's Critical Bandwidth Test to test for the continuity of mass ex- tinctions by applying kernel density estimation and bootstrap modality testing. The method im- proves on existing work based on searching for gaps in histograms, in that it does not depend on arbitrary choices of parameters (such as bin widths for histograms), and provides a direct estimate of the signi®cance of continuities or gaps in observed extinction intensities. I am thus able to test rigorously whether differences between mass extinctions and background extinctions are statisti- cally signi®cant.

  • Stratographic Coloumn of Iowa

    Iowa Stratographic Column November 4, 2013 QUATERNARY Holocene Series DeForest Formation Camp Creek Member Roberts Creek Member Turton Submember Mullenix Submember Gunder Formation Hatcher Submember Watkins Submember Corrington Formation Flack Formation Woden Formation West Okoboji Formation Pleistocene Series Wisconsinan Episode Peoria Formation Silt Facies Sand Facies Dows Formation Pilot Knob Member Lake Mills Member Morgan Member Alden Member Noah Creek Formation Sheldon Creek Formation Roxana/Pisgah Formation Illinoian Episode Loveland Formation Glasford Formation Kellerville Memeber Pre-Illinoian Wolf Creek Formation Hickory Hills Member Aurora Memeber Winthrop Memeber Alburnett Formation A glacial tills Lava Creek B Volcanic Ash B glacial tills Mesa Falls Volcanic Ash Huckleberry Ridge Volcanic Ash C glacial tills TERTIARY Salt & Pepper sands CRETACEOUS "Manson" Group "upper Colorado" Group Niobrara Formation Fort Benton ("lower Colorado ") Group Carlile Shale Greenhorn Limestone Graneros Shale Dakota Formation Woodbury Member Nishnabotna Member Windrow Formation Ostrander Member Iron Hill Member JURASSIC Fort Dodge Formation PENNSYLVANIAN (subsystem of Carboniferous System) Wabaunsee Group Wood Siding Formation Root Formation French Creek Shale Jim Creek Limestone Friedrich Shale Stotler Formation Grandhaven Limestone Dry Shale Dover Limestone Pillsbury Formation Nyman Coal Zeandale Formation Maple Hill Limestone Wamego Shale Tarkio Limestone Willard Shale Emporia Formation Elmont Limestone Harveyville Shale Reading Limestone Auburn
  • Appendix 3.Pdf

    Appendix 3.Pdf

    A Geoconservation perspective on the trace fossil record associated with the end – Ordovician mass extinction and glaciation in the Welsh Basin Item Type Thesis or dissertation Authors Nicholls, Keith H. Citation Nicholls, K. (2019). A Geoconservation perspective on the trace fossil record associated with the end – Ordovician mass extinction and glaciation in the Welsh Basin. (Doctoral dissertation). University of Chester, United Kingdom. Publisher University of Chester Rights Attribution-NonCommercial-NoDerivatives 4.0 International Download date 26/09/2021 02:37:15 Item License http://creativecommons.org/licenses/by-nc-nd/4.0/ Link to Item http://hdl.handle.net/10034/622234 International Chronostratigraphic Chart v2013/01 Erathem / Era System / Period Quaternary Neogene C e n o z o i c Paleogene Cretaceous M e s o z o i c Jurassic M e s o z o i c Jurassic Triassic Permian Carboniferous P a l Devonian e o z o i c P a l Devonian e o z o i c Silurian Ordovician s a n u a F y r Cambrian a n o i t u l o v E s ' i k s w o Ichnogeneric Diversity k p e 0 10 20 30 40 50 60 70 S 1 3 5 7 9 11 13 15 17 19 21 n 23 r e 25 d 27 o 29 M 31 33 35 37 39 T 41 43 i 45 47 m 49 e 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 Number of Ichnogenera (Treatise Part W) Ichnogeneric Diversity 0 10 20 30 40 50 60 70 1 3 5 7 9 11 13 15 17 19 21 n 23 r e 25 d 27 o 29 M 31 33 35 37 39 T 41 43 i 45 47 m 49 e 51 53 55 57 59 61 c i o 63 z 65 o e 67 a l 69 a 71 P 73 75 77 79 81 83 n 85 a i r 87 b 89 m 91 a 93 C Number of Ichnogenera (Treatise Part W)
  • Smithsonian Miscellaneous Collections Volume 148, Number 3

    Smithsonian Miscellaneous Collections Volume 148, Number 3

    —r SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 148, NUMBER 3 UPPER CAMBRIAN TRILOBITE FAUNAS OF NORTHEASTERN TENNESSEE (With 21 Plates) By FRANCO RASETTI The Johns Hopkins University Baltimore, Md. (Publication 4598) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION June 10, 1965 ,v, . SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 148, NUMBER 3 l^psfarrl| 3F«ttb UPPER CAMBRIAN TRILOBITE FAUNAS OF NORTHEASTERN TENNESSEE (With 21 Plates) By FRANCO RASETTI The Johns Hopkins University Baltimore, Md. (Publication 4598) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION June 10, 1965 <.%'^ Q^fii^ CONNECTICUT PRINTERS, INC. HARTFORD, CONN., U.S.A. CONTENTS Part I. Stratigraphy and Faunas Pj^ge Acknowledgments 3 Descriptions of Localities and Sections 3 General statement 3 Hawkins County 4 Hamblen County 10 Grainger County 12 Jefferson County I5 Union County 19 Claiborne County 21 Knox County 22 Monroe County 23 Purchase Ridge, Scott Coimty, Virginia 24 Index of Localities 25 Fauna of the Cedaria Zone 26 Fauna of the Crepicephalus Zone 28 Fauna of the Aphelaspis Zone 30 Part II. Systematic Paleontology General Statement 38 Descriptions of Trilobite Genera and Species Order AGNOSTIDA 38 Family AGNOSTIDAE 38 Order CORYNEXOCHIDA 39 Family DORYPYGIDAE 39 Order PTYCHOPARHDA 40 Family LONCHOCEPHALIDAE 40 Family CATILLICEPHALIDAE 44 Family CREPICEPHALIDAE 45 Family TRI CREPICEPHALIDAE 54 Family ASAPHISCIDAE 55 Family KINGSTONIIDAE 60 Family MENOMONIIDAE 61 Family NORWOODIIDAE 64 Family CEDARIIDAE 69 Family ELVINIIDAE 71 Family PTEROCEPHALIIDAE 72, PTYCHOPARHDA of uncertain affinities 102 Undetermined trilobites 112 References 115 Explanation of Plates 118 UPPER CAMBRIAN TRILOBITE FAUNAS OF NORTHEASTERN TENNESSEE By FRANCO RASETTI The Johns Hopkins University PART I. STRATIGRAPHY AND FAUNAS The purpose of this paper is both to describe the fossils and to present them in their proper stratigraphic setting.
  • Smithsonian Miscellaneous Collections Volume 101

    Smithsonian Miscellaneous Collections Volume 101

    SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 101. NUMBER 15 FIFTH CONTRIBUTION TO NOMENCLATURE OF CAMBRIAN FOSSILS BY CHARLES E. RESSER Curator, Division of Stratigraphic Paleontology U. S. National Museum (Publication 3682) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION MAY 22, 1942 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 101, NUMBER 15 FIFTH CONTRIBUTION TO NOMENCLATURE OF CAMBRIAN FOSSILS BY CHARLES E. RESSER Curator, Division of Stratigraphic Paleontology U. S. National Museum (Publication 3682) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION MAY 12, 1942 Z?>i Botb QBafhtnore (prcee BALTIMORE, MD., U. S. A. ' FIFTH CONTRIBUTION TO NOMENCLATURE OF CAMBRIAN FOSSILS By CHARLES E. RESSER Curator, Division of Stratigraphic Paleonlolo<jy, U. S. National Museum This is the fifth in the series of papers designed to care for changes necessary in the names of Cambrian fossils. When the fourth paper was published it was hoped that further changes would be so few and so obvious that they could be incorporated in the Cambrian bibliographic summary, and would not be required to appear first in a separate paper. But even now it is impossible to gather all of the known errors for rectification in this paper. For example, correc- tion of some errors must await the opportunity to examine the speci- mens because the published illustrations, obviously showing incorrect generic determinations, are too poor to permit a proper understanding of the fossil. In the other instances where new generic designations are clearly indicated, erection of new genera should await the pub- lication of a paper with illustrations, because better-preserved speci- mens are in hand, or undescribed species portray the generic charac- teristics more fully and should therefore be chosen as the genotypes.
  • Available Generic Names for Trilobites

    Available Generic Names for Trilobites

    AVAILABLE GENERIC NAMES FOR TRILOBITES P.A. JELL AND J.M. ADRAIN Jell, P.A. & Adrain, J.M. 30 8 2002: Available generic names for trilobites. Memoirs of the Queensland Museum 48(2): 331-553. Brisbane. ISSN0079-8835. Aconsolidated list of available generic names introduced since the beginning of the binomial nomenclature system for trilobites is presented for the first time. Each entry is accompanied by the author and date of availability, by the name of the type species, by a lithostratigraphic or biostratigraphic and geographic reference for the type species, by a family assignment and by an age indication of the type species at the Period level (e.g. MCAM, LDEV). A second listing of these names is taxonomically arranged in families with the families listed alphabetically, higher level classification being outside the scope of this work. We also provide a list of names that have apparently been applied to trilobites but which remain nomina nuda within the ICZN definition. Peter A. Jell, Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, Australia; Jonathan M. Adrain, Department of Geoscience, 121 Trowbridge Hall, Univ- ersity of Iowa, Iowa City, Iowa 52242, USA; 1 August 2002. p Trilobites, generic names, checklist. Trilobite fossils attracted the attention of could find. This list was copied on an early spirit humans in different parts of the world from the stencil machine to some 20 or more trilobite very beginning, probably even prehistoric times. workers around the world, principally those who In the 1700s various European natural historians would author the 1959 Treatise edition. Weller began systematic study of living and fossil also drew on this compilation for his Presidential organisms including trilobites.
  • Western North Greenland (Laurentia)

    Western North Greenland (Laurentia)

    BULLETIN OF THE GEOLOGICAL SOCIETY OF DENMARK · VOL. 69 · 2021 Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Miaolingian Series), western North Greenland (Laurentia) JOHN S. PEEL Peel, J.S. 2021. Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Mi- aolingian Series), western North Greenland (Laurentia). Bulletin of the Geological Society of Denmark, Vol. 69, pp. 1–33. ISSN 2245-7070. https://doi.org/10.37570/bgsd-2021-69-01 Trilobites dominantly of middle Cambrian (Miaolingian Series, Wuliuan Stage) Geological Society of Denmark age are described from the Telt Bugt Formation of Daugaard-Jensen Land, western https://2dgf.dk North Greenland (Laurentia), which is a correlative of the Cape Wood Formation of Inglefield Land and Ellesmere Island, Nunavut. Four biozones are recognised in Received 6 July 2020 Daugaard-Jensen Land, representing the Delamaran and Topazan regional stages Accepted in revised form of the western USA. The basal Plagiura–Poliella Biozone, with Mexicella cf. robusta, 16 December 2020 Kochiella, Fieldaspis? and Plagiura?, straddles the Cambrian Series 2–Miaolingian Series Published online 20 January 2021 boundary. It is overlain by the Mexicella mexicana Biozone, recognised for the first time in Greenland, with rare specimens of Caborcella arrojosensis. The Glossopleura walcotti © 2021 the authors. Re-use of material is Biozone, with Glossopleura, Clavaspidella and Polypleuraspis, dominates the succes- permitted, provided this work is cited. sion in eastern Daugaard-Jensen Land but is seemingly not represented in the type Creative Commons License CC BY: section in western outcrops, likely reflecting the drastic thinning of the formation https://creativecommons.org/licenses/by/4.0/ towards the north-west.
  • A Deposit Model for Mississippi Valley-Type Lead-Zinc Ores

    A Deposit Model for Mississippi Valley-Type Lead-Zinc Ores

    A Deposit Model for Mississippi Valley-Type Lead-Zinc Ores Chapter A of Mineral Deposit Models for Resource Assessment 2 cm Sample of spheroidal sphalerite with dendritic sphalerite, galena, and iron sulfides (pyrite plus marcasite) from the Pomorzany mine. Note the “up direction” is indicated by “snow-on-the-roof” texture of galena and Scientificsphalerite Investigations alnong colloform Report layers of2010–5070–A light-colored spahlerite. Hydrothermal sulfide clasts in the left center of the sample are encrusted by sphalerire and iron sulfides. Size of sample is 20x13 cm. Photo by David Leach. U.S. Department of the Interior U.S. Geological Survey COVER: Sample of spheroidal sphalerite with dendritic sphalerite, galena, and iron sulfides (pyrite plus mar- casite) from Pomorzany mine. Note the “up direction” is indicated by “snow-on-the-roof” texture of galena and sphalerite along colloform layers of light-colored sphalerite. Hydrothermal sulfide clasts in the left center of the sample are encrusted by sphalerite and iron sulfides. Size of sample is 20x13 centimeters. (Photograph by David L. Leach, U.S. Geological Survey.) A Deposit Model for Mississippi Valley- Type Lead-Zinc Ores By David L. Leach, Ryan D. Taylor, David L. Fey, Sharon F. Diehl, and Richard W. Saltus Chapter A of Mineral Deposit Models for Resource Assessment Scientific Investigations Report 2010–5070–A U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S.
  • Lee-Riding-2018.Pdf

    Lee-Riding-2018.Pdf

    Earth-Science Reviews 181 (2018) 98–121 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Marine oxygenation, lithistid sponges, and the early history of Paleozoic T skeletal reefs ⁎ Jeong-Hyun Leea, , Robert Ridingb a Department of Geology and Earth Environmental Sciences, Chungnam National University, Daejeon 34134, Republic of Korea b Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA ARTICLE INFO ABSTRACT Keywords: Microbial carbonates were major components of early Paleozoic reefs until coral-stromatoporoid-bryozoan reefs Cambrian appeared in the mid-Ordovician. Microbial reefs were augmented by archaeocyath sponges for ~15 Myr in the Reef gap early Cambrian, by lithistid sponges for the remaining ~25 Myr of the Cambrian, and then by lithistid, calathiid Dysoxia and pulchrilaminid sponges for the first ~25 Myr of the Ordovician. The factors responsible for mid–late Hypoxia Cambrian microbial-lithistid sponge reef dominance remain unclear. Although oxygen increase appears to have Lithistid sponge-microbial reef significantly contributed to the early Cambrian ‘Explosion’ of marine animal life, it was followed by a prolonged period dominated by ‘greenhouse’ conditions, as sea-level rose and CO2 increased. The mid–late Cambrian was unusually warm, and these elevated temperatures can be expected to have lowered oxygen solubility, and to have promoted widespread thermal stratification resulting in marine dysoxia and hypoxia. Greenhouse condi- tions would also have stimulated carbonate platform development, locally further limiting shallow-water cir- culation. Low marine oxygenation has been linked to episodic extinctions of phytoplankton, trilobites and other metazoans during the mid–late Cambrian.
  • (Upper Cambrian, Paibian) Trilobite Faunule in the Central Conasauga River Valley, North Georgia, Usa

    (Upper Cambrian, Paibian) Trilobite Faunule in the Central Conasauga River Valley, North Georgia, Usa

    Schwimmer.fm Page 31 Monday, June 18, 2012 11:54 AM SOUTHEASTERN GEOLOGY V. 49, No. 1, June 2012, p. 31-41 AN APHELASPIS ZONE (UPPER CAMBRIAN, PAIBIAN) TRILOBITE FAUNULE IN THE CENTRAL CONASAUGA RIVER VALLEY, NORTH GEORGIA, USA DAVID R. SCHWIMMER1 WILLIAM M. MONTANTE2 1Department of Chemistry & Geology Columbus State University, 4225 University Avenue, Columbus, Georgia 31907, USA <[email protected]> 2Marsh & McLennan, Inc., 3560 Lenox Road, Suite 2400, Atlanta, Georgia 30326, USA <[email protected]> ABSTRACT shelf-to-basin break, which is interpreted to be east of the Alabama Promontory and in Middle and Upper Cambrian strata the Tennessee Embayment. The preserva- (Cambrian Series 3 and Furongian) in the tion of abundant aphelaspine specimens by southernmost Appalachians (Tennessee to bioimmuration events may have been the re- Alabama) comprise the Conasauga Forma- sult of mudflows down the shelf-to-basin tion or Group. Heretofore, the youngest re- slope. ported Conasauga beds in the Valley and Ridge Province of Georgia were of the late INTRODUCTION Middle Cambrian (Series 3: Drumian) Bo- laspidella Zone, located on the western state Trilobites and associated biota from Middle boundary in the valley of the Coosa River. Cambrian beds of the Conasauga Formation in Two new localities sited eastward in the Co- northwestern Georgia have been described by nasauga River Valley, yield a diagnostic suite Walcott, 1916a, 1916b; Butts, 1926; Resser, of trilobites from the Upper Cambrian 1938; Palmer, 1962; Schwimmer, 1989; Aphelaspis Zone. Very abundant, Schwimmer and Montante, 2007. These fossils polymeroid trilobites at the primary locality and deposits come from exposures within the are referable to Aphelaspis brachyphasis, valley of the Coosa River, in Floyd County, which is a species known previously in west- Georgia, and adjoining Cherokee County, Ala- ern North America.
  • Late Dresbachian (Late Cambrian) Biostratigraphy of North America

    Late Dresbachian (Late Cambrian) Biostratigraphy of North America

    CHRISTINA LOCHMAN-BALK Department of Geosdence, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801 Late Dresbachian (Late Cambrian) Biostratigraphy of North America ABSTRACT bachian Aphelaspis Zone (Howell and Dresbachian time in the central Texas others, 1944) into an older Aphelaspis Zone section, with only a very short hiatus? before An examination of the taxonomic com- and a younger post-Aphelaspis Zone. the appearance of the Elvinia Zone fauna. position of the North American late Trilobites and brachiopods assigned by The short hiatus? refers to the well-defined Dresbachian faunules described to date Palmer to the Aphelaspis Zone are listed in faunal break and disconformity between the indicates that there is an Aphelaspis Zone Table 1. In the basal beds of the zone, Palmer Lion Mountain Sandstone Member of the faunal assemblage characteristic of the early Riley Formation and the Welge Sandstone half of the late Dresbachian Stage and a Member of the Wilberns Formation (Loch- TABLE 1. TRILOBITES ÄND BRACHIOPODS ASSIGNED TO Dunderbergia Zone faunal assemblage APHELASPIS ZONE, RILEY FORMATION, TEXAS, man, 1938; Freeman, 1969). characteristic of the later half. The diagnos- BY PALMER (1955) From 1951, Palmer was engaged in the tic elements of each of the assemblages are Aphelaspis walcotti study of the Late Cambrian faunas of the listed, and the biozones of the common Labiostria (now Aphelaspis) conveximavginata Great Basin and published late Dresbachian Labiostria (now Aphelaspis) platifrons trilobite genera are noted so that correct Dunderbergia variagranula faunal lists in Nolan and others (1956) and Eaaschella (now Glaphyraspis) omata intracontinental correlations may be made.
  • An Appraisal of the Great Basin Middle Cambrian Trilobites Described Before 1900

    An Appraisal of the Great Basin Middle Cambrian Trilobites Described Before 1900

    An Appraisal of the Great Basin Middle Cambrian Trilobites Described Before 1900 By ALLISON R. PALMER A SHORTER CONTRIBUTION TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 264-D Of the 2ty species described prior to I(?OO, 2/ are redescribed and 2C} refigured, and a new name is proposedfor I species UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1954 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price $1 (paper cover) CONTENTS Page Abstract..__________________________________ 55 Introduction ________________________________ 55 Original and present taxonomic names of species. 57 Stratigraphic distribution of species ____________ 57 Collection localities._________________________ 58 Systematic descriptions.______________________ 59 Literature cited____________________________ 82 Index __-_-__-__---_--______________________ 85 ILLUSTRATIONS [Plates 13-17 follow page 86] PLATE 13. Agnostidae and Dolichometopidae 14. Dorypygidae 15. Oryctocephalidae, Dorypygidae, Zacanthoididae, and Ptychoparioidea 16. Ptychoparioidea 17. Ptychoparioidea FIGUBE 3. Index map showing collecting localities____________________________ . Page 56 in A SHORTER CONTRIBUTION TO GENERAL GEOLOGY AN APPRAISAL OF THE GREAT BASIN MIDDLE CAMBRIAN TRILOBITES DESCRIBED BEFORE 1900 By ALLISON R. PALMER ABSTRACT the species and changes in their generic assignments All 29 species of Middle Cambrian trilobites