Precambrian to Earliest Mississippian Stratigraphy, Geologic History, and Paleogeography of Northwestern Colorado and West-Central Colorado
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The Sedimentology and Mineralogy of the River Uranium Deposit Near Phuthaditjhaba, Qwa-Qwa
PER-74 THE SEDIMENTOLOGY AND MINERALOGY OF THE RIVER URANIUM DEPOSIT NEAR PHUTHADITJHABA, QWA-QWA by J. P. le Roux NUCLEAR DEVELOPMENT CORPORATION OF SOUTH AFRICA (PTY) LTD NUCOR PRIVATE MO X2M PRETORIA 0001 m•v OCTOBER 1982 PER-74- THE SEDIMENTOLOGY AND MINERALOGY OF THE RIVER URANIUM DEPOSIT NEAR PHUTHADITJHABA, QWA-QWA b/ H.J. Brynard * J.P. le Roux * * Geology Department POSTAL ADDRESS: Private Bag X256 PRETORIA 0001 PELINDABA August 1982 ISBN 0-86960-747-2 CONTENTS SAMEVATTING ABSTRACT 1. INTRODUCTION 1 2. SEDIMENTOLOGY 1 2.1 Introduction 1 2.2 Depositional Environment 2 2.2.1 Palaeocurrents 2 2.2.2 Sedimentary structures and vertical profiles 5 2.2.3 Borehole analysis 15 2.3 Uranium Mineralisation 24 2.4 Conclusions and Recommendations 31 3. MINERALOGY 33 3.1 Introduction 33 3.2 Procedure 33 3.3 Terminology Relating to Carbon Content 34 3.4 Petrographic Description of the Sediments 34 3.5 Uranium Distribution 39 3.6 Minor and Trace Elements 42 3.7 Petrogenesis 43 3.8 Extraction Metallurgy 43 4. REFERENCES 44 PER-74-ii SAMEVATTING 'n Sedimentologiese en mineralogiese ondersoek is van die River-af setting uittigevoer wat deur Mynboukorporasie (Edms) Bpk in Qwa-Qwa, 15 km suaidwes van Phu triad it jnaba, ontdek is. Die ertsliggaam is in íluviale sand-steen van die boonste Elliot- formasie geleë. Palleostroomrigtings dui op 'n riviersisteem met 'n lae tot baie lae 3d.nuositeit en met "h vektor-gemiddelde aanvoer- rigting van 062°. 'n Studie van sedimentere strukture en korrelgroottes in kranssnitte is deuir to ontleding van boorgatlogs aangevul wat die sedimentêre afsettingsoragewing as h gevlegte stroom van die Donjek-tipe onthul. -
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. -
Bailey Mark Hopkins 1980
AN ABSTRACT OF THE THESIS OF MARK H. BAILEY for the degree of Master of Science in Geology presented on June 7, 1979 Title: BEDROCK GEOLOGY OF WESTERN TAYLOR PARK, GUNNISON COUNTY, COLORADO Signature redacted for privacy. Abstract approved: I ._&V_j - Dr. Robert D. Lawrence The western Taylor Park area covers about 65 square miles on the western flank of the Sawatch Range. It is underlain chiefly by Precambrian rocks, partiallycovered on the east by glacial debris andoverlapped on the west and south by Paleozoic sedimentary rocks. The Precambrian rocks include a group ofmetasedimen- tary rocks of an undetermined age greaterthan 1700 m.y. The metasedimentary rocks include five mineralogicallydis- tinct units, quartzite, quartz-muscovite schist, quartz- epidote schist, quartz-plagioclase-biotite schist,and quartz-biotite-microcline-sillimaflite schist. The higher grade sillimanite-bearing biotite schists arerestricted to the western half of the map area and closelyassociated with the Forest Hill granitic rocks. The metasedimentary rocks were intruded twiceduring Precambrian time. The oldest intrusive event resulted in syntectonic emplacement of granodiorite and biotite tona- lite rocks. These rocks correlate with the 1700 m.y.old Denny Creek granodiorite gneiss and Kroenkegranodiorite which are mapped and informally named in the adjoining Mount Harvard quadrangle. The second, post-tectonic, igneous eventproduced granitic rocks that are dated at 1030 m.y. byRb-Sr meth- ods. These rocks include two comagmatic graniticphases, the Forest Hill porphyritic granite and the ForestHill cataclastic granite. A third phase, the Forest Hill horn- blende granodiorite, intrudes the porphyritic graniteand, therefore, is younger than the granitic phases. The 1030 m.y. -
The Evolution and Distribution of Life in the Precambrian Eon-Global Perspective and the Indian Record 765
The evolution and distribution of life in the Precambrian eon-Global perspective and the Indian record 765 The evolution and distribution of life in the Precambrian eon-Global perspective and the Indian record M SHARMA* and Y SHUKLA Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow 226 007, India *Corresponding author (Email, [email protected]) The discovery of Precambrian microfossils in 1954 opened a new vista of investigations in the fi eld of evolution of life. Although the Precambrian encompasses 87% of the earth’s history, the pace of organismal evolution was quite slow. The life forms as categorised today in the three principal domains viz. the Bacteria, the Archaea and the Eucarya evolved during this period. In this paper, we review the advancements made in the Precambrian palaeontology and its contribution in understanding the evolution of life forms on earth. These studies have enriched the data base on the Precambrian life. Most of the direct evidence includes fossil prokaryotes, protists, advanced algal fossils, acritarchs, and the indirect evidence is represented by the stromatolites, trace fossils and geochemical fossils signatures. The Precambrian fossils are preserved in the form of compressions, impressions, and permineralized and biomineralized remains. [Sharma M and Shukla Y 2009 The evolution and distribution of life in the Precambrian eon-Global perspective and the Indian record; J. Biosci. 34 765–776] DOI 10.1007/s12038-009-0065-8 1. Introduction suggested that all the living forms can be grouped into three principal domains viz. the Bacteria, the Archaea, and The sudden appearance and radiation of both skeletal and the Eucarya (Woese 1987, 2002; Woese et al. -
Chapter 2 Paleozoic Stratigraphy of the Grand Canyon
CHAPTER 2 PALEOZOIC STRATIGRAPHY OF THE GRAND CANYON PAIGE KERCHER INTRODUCTION The Paleozoic Era of the Phanerozoic Eon is defined as the time between 542 and 251 million years before the present (ICS 2010). The Paleozoic Era began with the evolution of most major animal phyla present today, sparked by the novel adaptation of skeletal hard parts. Organisms continued to diversify throughout the Paleozoic into increasingly adaptive and complex life forms, including the first vertebrates, terrestrial plants and animals, forests and seed plants, reptiles, and flying insects. Vast coal swamps covered much of mid- to low-latitude continental environments in the late Paleozoic as the supercontinent Pangaea began to amalgamate. The hardiest taxa survived the multiple global glaciations and mass extinctions that have come to define major time boundaries of this era. Paleozoic North America existed primarily at mid to low latitudes and experienced multiple major orogenies and continental collisions. For much of the Paleozoic, North America’s southwestern margin ran through Nevada and Arizona – California did not yet exist (Appendix B). The flat-lying Paleozoic rocks of the Grand Canyon, though incomplete, form a record of a continental margin repeatedly inundated and vacated by shallow seas (Appendix A). IMPORTANT STRATIGRAPHIC PRINCIPLES AND CONCEPTS • Principle of Original Horizontality – In most cases, depositional processes produce flat-lying sedimentary layers. Notable exceptions include blanketing ash sheets, and cross-stratification developed on sloped surfaces. • Principle of Superposition – In an undisturbed sequence, older strata lie below younger strata; a package of sedimentary layers youngs upward. • Principle of Lateral Continuity – A layer of sediment extends laterally in all directions until it naturally pinches out or abuts the walls of its confining basin. -
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) -
Denudation History and Internal Structure of the Front Range and Wet Mountains, Colorado, Based on Apatite-Fission-Track Thermoc
NEW MEXICO BUREAU OF GEOLOGY & MINERAL RESOURCES, BULLETIN 160, 2004 41 Denudation history and internal structure of the Front Range and Wet Mountains, Colorado, based on apatitefissiontrack thermochronology 1 2 1Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM 87801Shari A. Kelley and Charles E. Chapin 2New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining and Technology, Socorro, NM 87801 Abstract An apatite fissiontrack (AFT) partial annealing zone (PAZ) that developed during Late Cretaceous time provides a structural datum for addressing questions concerning the timing and magnitude of denudation, as well as the structural style of Laramide deformation, in the Front Range and Wet Mountains of Colorado. AFT cooling ages are also used to estimate the magnitude and sense of dis placement across faults and to differentiate between exhumation and faultgenerated topography. AFT ages at low elevationX along the eastern margin of the southern Front Range between Golden and Colorado Springs are from 100 to 270 Ma, and the mean track lengths are short (10–12.5 µm). Old AFT ages (> 100 Ma) are also found along the western margin of the Front Range along the Elkhorn thrust fault. In contrast AFT ages of 45–75 Ma and relatively long mean track lengths (12.5–14 µm) are common in the interior of the range. The AFT ages generally decrease across northwesttrending faults toward the center of the range. The base of a fossil PAZ, which separates AFT cooling ages of 45– 70 Ma at low elevations from AFT ages > 100 Ma at higher elevations, is exposed on the south side of Pikes Peak, on Mt. -
Revised Correlation of Silurian Provincial Series of North America with Global and Regional Chronostratigraphic Units 13 and D Ccarb Chemostratigraphy
Revised correlation of Silurian Provincial Series of North America with global and regional chronostratigraphic units 13 and d Ccarb chemostratigraphy BRADLEY D. CRAMER, CARLTON E. BRETT, MICHAEL J. MELCHIN, PEEP MA¨ NNIK, MARK A. KLEFF- NER, PATRICK I. MCLAUGHLIN, DAVID K. LOYDELL, AXEL MUNNECKE, LENNART JEPPSSON, CARLO CORRADINI, FRANK R. BRUNTON AND MATTHEW R. SALTZMAN Cramer, B.D., Brett, C.E., Melchin, M.J., Ma¨nnik, P., Kleffner, M.A., McLaughlin, P.I., Loydell, D.K., Munnecke, A., Jeppsson, L., Corradini, C., Brunton, F.R. & Saltzman, M.R. 2011: Revised correlation of Silurian Provincial Series of North America with global 13 and regional chronostratigraphic units and d Ccarb chemostratigraphy. Lethaia,Vol.44, pp. 185–202. Recent revisions to the biostratigraphic and chronostratigraphic assignment of strata from the type area of the Niagaran Provincial Series (a regional chronostratigraphic unit) have demonstrated the need to revise the chronostratigraphic correlation of the Silurian System of North America. Recently, the working group to restudy the base of the Wen- lock Series has developed an extremely high-resolution global chronostratigraphy for the Telychian and Sheinwoodian stages by integrating graptolite and conodont biostratigra- 13 phy with carbonate carbon isotope (d Ccarb) chemostratigraphy. This improved global chronostratigraphy has required such significant chronostratigraphic revisions to the North American succession that much of the Silurian System in North America is cur- rently in a state of flux and needs further refinement. This report serves as an update of the progress on recalibrating the global chronostratigraphic correlation of North Ameri- can Provincial Series and Stage boundaries in their type area. -
Geologic History of the Earth 1 the Precambrian
Geologic History of the Earth 1 algae = very simple plants that Geologists are scientists who study the structure grow in or near the water of rocks and the history of the Earth. By looking at first = in the beginning at and examining layers of rocks and the fossils basic = main, important they contain they are able to tell us what the beginning = start Earth looked like at a certain time in history and billion = a thousand million what kind of plants and animals lived at that breathe = to take air into your lungs and push it out again time. carbon dioxide = gas that is produced when you breathe Scientists think that the Earth was probably formed at the same time as the rest out of our solar system, about 4.6 billion years ago. The solar system may have be- certain = special gun as a cloud of dust, from which the sun and the planets evolved. Small par- complex = something that has ticles crashed into each other to create bigger objects, which then turned into many different parts smaller or larger planets. Our Earth is made up of three basic layers. The cen- consist of = to be made up of tre has a core made of iron and nickel. Around it is a thick layer of rock called contain = have in them the mantle and around that is a thin layer of rock called the crust. core = the hard centre of an object Over 4 billion years ago the Earth was totally different from the planet we live create = make on today. -
Sedimentology and Stratigraphy
SEDIMENTOLOGY AND STRATIGRAPHY COURSE SYLLABUS FALL 2003 Meeting times This class meets on Tuesday and Thursday, from 9:55-11:35 a.m., with a required lab section on Thursday from 1:30-4:30 p.m. As you will see below, I have designed this course so that it does not follow a strict “lecture/lab” format. Rather, we will do lab-like work interspersed with lecture throughout the entire schedule. Instructor Information Dr. Thomas Hickson Office: OSS 117 Ph.D., 1999, Stanford University Phone: 651-962-5241 e-mail: [email protected] Office hours: Greetings! Pretty much all of you have had a class from me at one time or another. You are about to enter the class that I care about the most, Sedimentology and Stratigraphy. I am a sedimentologist by training. I spent at least eight years of my life doing research in this field—as part of a PhD and as a post-doctoral researcher at the U of M—and I continue this work to today. I have taught the course twice before, in a pretty standard format. I lectured. You did labs. We went on field trips. I hoped that, in the end, you’d see how it all hung together in this great, organic whole. Unfortunately, this last step never really seemed to happen. As a result, I took a large chunk of the summer (of ’03) and worked toward redesigning this course. I went to an National Science Foundation/ National Association of Geoscience Teachers workshop at Hamilton College (in New York) entitled “Designing effective and innovative courses in the geosciences” specifically to work on this course. -
The Geologic Time Scale Is the Eon
Exploring Geologic Time Poster Illustrated Teacher's Guide #35-1145 Paper #35-1146 Laminated Background Geologic Time Scale Basics The history of the Earth covers a vast expanse of time, so scientists divide it into smaller sections that are associ- ated with particular events that have occurred in the past.The approximate time range of each time span is shown on the poster.The largest time span of the geologic time scale is the eon. It is an indefinitely long period of time that contains at least two eras. Geologic time is divided into two eons.The more ancient eon is called the Precambrian, and the more recent is the Phanerozoic. Each eon is subdivided into smaller spans called eras.The Precambrian eon is divided from most ancient into the Hadean era, Archean era, and Proterozoic era. See Figure 1. Precambrian Eon Proterozoic Era 2500 - 550 million years ago Archaean Era 3800 - 2500 million years ago Hadean Era 4600 - 3800 million years ago Figure 1. Eras of the Precambrian Eon Single-celled and simple multicelled organisms first developed during the Precambrian eon. There are many fos- sils from this time because the sea-dwelling creatures were trapped in sediments and preserved. The Phanerozoic eon is subdivided into three eras – the Paleozoic era, Mesozoic era, and Cenozoic era. An era is often divided into several smaller time spans called periods. For example, the Paleozoic era is divided into the Cambrian, Ordovician, Silurian, Devonian, Carboniferous,and Permian periods. Paleozoic Era Permian Period 300 - 250 million years ago Carboniferous Period 350 - 300 million years ago Devonian Period 400 - 350 million years ago Silurian Period 450 - 400 million years ago Ordovician Period 500 - 450 million years ago Cambrian Period 550 - 500 million years ago Figure 2. -
Pennsylvanian Boundary Unconformity in Marine Carbonate Successions
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Dissertations & Theses in Earth and Atmospheric Earth and Atmospheric Sciences, Department of Sciences Summer 6-2014 ORIGIN AND DISTRIBUTION OF THE MISSISSIPPIAN – PENNSYLVANIAN BOUNDARY UNCONFORMITY IN MARINE CARBONATE SUCCESSIONS WITH A CASE STUDY OF THE KARST DEVELOPMENT ATOP THE MADISON FORMATION IN THE BIGHORN BASIN, WYOMING. Lucien Nana Yobo University of Nebraska-Lincoln, [email protected] Follow this and additional works at: http://digitalcommons.unl.edu/geoscidiss Part of the Geochemistry Commons, Geology Commons, Sedimentology Commons, and the Stratigraphy Commons Nana Yobo, Lucien, "ORIGIN AND DISTRIBUTION OF THE MISSISSIPPIAN – PENNSYLVANIAN BOUNDARY UNCONFORMITY IN MARINE CARBONATE SUCCESSIONS WITH A CASE STUDY OF THE KARST DEVELOPMENT ATOP THE MADISON FORMATION IN THE BIGHORN BASIN, WYOMING." (2014). Dissertations & Theses in Earth and Atmospheric Sciences. 59. http://digitalcommons.unl.edu/geoscidiss/59 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Dissertations & Theses in Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. ORIGIN AND DISTRIBUTION OF THE MISSISSIPPIAN – PENNSYLVANIAN BOUNDARY UNCONFORMITY IN MARINE CARBONATE SUCCESSIONS WITH A CASE STUDY OF THE KARST DEVELOPMENT ATOP THE MADISON FORMATION IN THE BIGHORN BASIN, WYOMING. By Luscalors Lucien Nana Yobo A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Earth and Atmospheric Sciences Under the Supervision of Professor Tracy D.