Geologic Time Notes Earth Realms Form And
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Integrative and Comparative Biology Integrative and Comparative Biology, Volume 58, Number 4, Pp
Integrative and Comparative Biology Integrative and Comparative Biology, volume 58, number 4, pp. 605–622 doi:10.1093/icb/icy088 Society for Integrative and Comparative Biology SYMPOSIUM INTRODUCTION The Temporal and Environmental Context of Early Animal Evolution: Considering All the Ingredients of an “Explosion” Downloaded from https://academic.oup.com/icb/article-abstract/58/4/605/5056706 by Stanford Medical Center user on 15 October 2018 Erik A. Sperling1 and Richard G. Stockey Department of Geological Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305, USA From the symposium “From Small and Squishy to Big and Armored: Genomic, Ecological and Paleontological Insights into the Early Evolution of Animals” presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3–7, 2018 at San Francisco, California. 1E-mail: [email protected] Synopsis Animals originated and evolved during a unique time in Earth history—the Neoproterozoic Era. This paper aims to discuss (1) when landmark events in early animal evolution occurred, and (2) the environmental context of these evolutionary milestones, and how such factors may have affected ecosystems and body plans. With respect to timing, molecular clock studies—utilizing a diversity of methodologies—agree that animal multicellularity had arisen by 800 million years ago (Ma) (Tonian period), the bilaterian body plan by 650 Ma (Cryogenian), and divergences between sister phyla occurred 560–540 Ma (late Ediacaran). Most purported Tonian and Cryogenian animal body fossils are unlikely to be correctly identified, but independent support for the presence of pre-Ediacaran animals is recorded by organic geochemical biomarkers produced by demosponges. -
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Dorjnamjaa et al. Mongolian Geoscientist 49 (2019) 41-49 https://doi.org/10.5564/mgs.v0i49.1226 Mongolian Geoscientist Review paper New scientific direction of the bacterial paleontology in Mongolia: an essence of investigation * Dorj Dorjnamjaa , Gundsambuu Altanshagai, Batkhuyag Enkhbaatar Department of Paleontology, Institute of Paleontology, Mongolian Academy of Sciences, Ulaanbaatar 15160, Mongolia *Corresponding author. Email: [email protected] ARTICLE INFO ABSTRACT Article history: We review the initial development of Bacterial Paleontology in Mongolia and Received 10 September 2019 present some electron microscopic images of fossil bacteria in different stages of Accepted 9 October 2019 preservation in sedimentary rocks. Indeed bacterial paleontology is one the youngest branches of paleontology. It has began in the end of 20th century and has developed rapidly in recent years. The main tasks of bacterial paleontology are detailed investigation of fossil microorganisms, in particular their morphology and sizes, conditions of burial and products of habitation that are reflected in lithological and geochemical features of rocks. Bacterial paleontology deals with fossil materials and is useful in analysis of the genesis of sedimentary rocks, and sedimentary mineral resources including oil and gas. The traditional paleontology is especially significant for evolution theory, biostratigraphy, biogeography and paleoecology; however bacterial paleontology is an essential first of all for sedimentology and for theories sedimentary ore genesis or biometallogeny Keywords: microfossils, phosphorite, sedimentary rocks, lagerstatten, biometallogeny INTRODUCTION all the microorganisms had lived and propagated Bacteria or microbes preserved well as fossils in without breakdowns. Bacterial paleontological various rocks, especially in sedimentary rocks data accompanied by the data on the first origin alike natural substances. -
Hutton, Kelvin, and the Great Earth Debates. • the Beginnings of Modern Geology “All Natural Processes That Affect the Earth’S Crust (Erosion, Deposition, • Ca
Chapter 1 The Science of Geology An Introduction to Geology • Geology - the science that pursues an understanding of planet Earth • Physical geology - examines the materials composing Earth and seeks to understand the many processes that operate beneath and upon its surface • Historical geology - seeks an understanding of the origin of “If there is an interesting place you want to go, there is Earth and its development interesting geology that you can study there” through time Mersin ophiolite, (Cappadocia, Central Turkey). Turkey The Science of Geology The Science of Geology 1.3: satellite image of Mt. Vesuvius, Italy. • Some historical views • Geology, people, and the environment of the Earth • Many important relationships exist between • Aristotle, 300 BC; people and the natural environment • James Ussher, ca. 1600, ‘Earth was created in Problems and issues 4004 BC;’ addressed by • Catastrophism geology include • Earth’s features formed through • Natural hazards, sudden and violent resources, world changes. ‘The Dog population growth, of and environmental Pompeii’ issues Dwelling in Goreme, Cappadocia The Science of Geology Hutton, Kelvin, and the great Earth debates. • The beginnings of modern geology “All natural processes that affect the Earth’s crust (erosion, deposition, • ca. 1780, James Huton’s volcanic eruptions, faulting, glaciation Theory of the Earth; etc.) operate with the same intensity • Uniformitarianism: “the and under the same set of physical processes that operate constraints now as in the geologic past.” today have operated in “(as to the age of Earth) we see no the past.” vestige of a beginning, no prospect of • a uniformitarian view of an end.” Earth requires a vast These points are incorrect - why? amount of time…. -
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. -
Chapter 8: Geologic Time
Chapter 8: Geologic Time 1. The Art of Time 2. The History of Relative Time 3. Geologic Time 4. Numerical Time 5. Rates of Change Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Geologic Time How long has this landscape looked like this? How can you tell? Will your grandchildren see this if they hike here in 80 years? The Good Earth/Chapter 8: Geologic Time The Art of Time How would you create a piece of art to illustrate the passage of time? How do you think the Earth itself illustrates the passage of time? What time scale is illustrated in the example above? How well does this relate to geological time/geological forces? The Good Earth/Chapter 8: Geologic Time Go back to the Table of Contents Go to the next section: The History of (Relative) Time The Good Earth/Chapter 8: Geologic Time The History of (Relative) Time Paradigm shift: 17th century – science was a baby and geology as a discipline did not exist. Today, hypothesis testing method supports a geologic (scientific) age for the earth as opposed to a biblical age. Structures such as the oldest Egyptian pyramids (2650-2150 B.C.) and the Great Wall of China (688 B.C.) fall within a historical timeline that humans can relate to, while geological events may seem to have happened before time existed! The Good Earth/Chapter 8: Geologic Time The History of (Relative) Time • Relative Time = which A came first, second… − Grand Canyon – B excellent model − Which do you think happened first – the The Grand Canyon – rock layers record thousands of millions of years of geologic history. -
Gawler Craton: Half a Billion Years Older Than Previously Thought!
ISSUE 92 Dec 2008 Foundations of South Australia discovered Gawler Craton: half a billion years older than previously thought! Geoff Fraser, Chris Foudoulis, Narelle Neumann, Keith Sircombe (Geoscience Australia) Stacey McAvaney, Anthony Reid, Michael Szpunar (Primary Industries and Resources South Australia) Recent geochronology results obtained using Geoscience Australia’s a billion years older than the Sensitive High Resolution Ion Microprobe (SHRIMP) have identified oldest previously-dated rock from Mesoarchean rocks (about 3150 million years old) in the eastern South Australia, making these Gawler Craton, South Australia. These rocks are approximately half the oldest rocks yet discovered in 136° 137° Australia outside the Pilbara and Port Augusta Yilgarn Craton areas of Western 08GA-G01 Australia. A series of seismic transects are being collected across selected regions of the Australian 33° See Inset below Whyalla continent as part of Geoscience Kimba Australia’s Onshore Energy SOUTH Security Program. One of these AUSTRALIA seismic transects, collected in June 2008, traverses the northern Cowell Eyre Peninsula of South Australia Iron Monarch (figure 1). When processed, the seismic data will provide an east– 23 Mile Wallaroo west cross-section of the eastern 34° margin of the Gawler Craton. Spencer Moonta Gulf This region hosts significant CUMMINS uranium, geothermal, copper- Iron Baron/ TUMBY BAY Iron Prince gold, gold and iron resources. Maitland To assist the interpretation of 08-3449-1 0 50 km the seismic data and the current geological mapping program of Mesoarchean granite NT QLD Primary Industries and Resources WA Seismic survey route SA Road South Australia, a program of NSW VIC Railway geochronology is underway to Mineral occurence TAS Town/locality determine the ages of major rock units crossed by the seismic line. -
Chapter 7: the Age of Earth
Earth and Life History Ancient Carvings These beautiful formations in Paria Canyon, along the boder of Arizona and Utah, were carved by the Paria River about 5.4 million years ago. 40,000–12,000 1875 Years Ago Henry Hancock discovers that a Organisms are trapped tooth more than 23 cm long and in tar pits found at La 9 cm wide may be from a saber- Brea (Los Angeles, tooth cat; realizes the bones at California). La Brea could be ancient. A.D. 1 1750 1800 1850 1900 1795 1896 James Hutton pro- Henri Becquerel dis- poses idea that covers radioactivity of natural processes uranium salts not long forming rock layers after Wilhelm Conrad occur uniformly Roentgen discovers throughout time. the X ray in 1895. 278 (bkgd)Layne Kennedy/CORBIS, (t)Albert Copley/Visuals Unlimited, (b)American Institute of Physics/Emilio Segrè Visual Archives To learn more about geologists and paleontologists and their work, visit ca7.msscience.com. Interactive Time Line To learn more about these events and others, visit ca7.msscience.com. c. 1910–1915 1980 1990 First scientific digs of the La Luis and Walter Alvarez from UC NASA researchers Kevin Pope, Brea Tar Pits are made by Berkeley propose that an asteroid Adriana Ocampo, and Charles scientists from the Univer- crashed into Earth 65 million years Duller, identify a huge crater sity of California; about ago, causing the sudden extinction in the Yucatan, Mexico, that 170,000 fossils found. of dinosaurs and many other living they think is the site of the things. asteroid crash. 1900 1920 1940 1960 1980 2000 2020 1913 1967 November 2002 First numeric time scale of geo- Richard Leakey finds two The National Science Founda- logic ages is proposed by skulls and uses new technol- tion launches a program, sci- Arthur Holmes of Great Britain; ogy to date objects more entists from around the world he used radioactive means to accurately; one is 195,000 will verify dates and class of measure the age of Earth years old, the oldest for a old specimens and analyze (about 4 billion years old). -
1 TIMESCALE for CLIMATIC EVENTS of SUBBOREAL/SUBATLANTIC TRANSITION RECORDED at the VALAKUPIAI SITE, LITHUANIA Jacek Pawlyta1,2
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by BSU Digital Library RADIOCARBON, Vol 49, Nr 2, 2007, p 1–9 © 2007 by the Arizona Board of Regents on behalf of the University of Arizona TIMESCALE FOR CLIMATIC EVENTS OF SUBBOREAL/SUBATLANTIC TRANSITION RECORDED AT THE VALAKUPIAI SITE, LITHUANIA Jacek Pawlyta1,2 • Algirdas Gaigalas3 • Adam MichczyÒski1 • Anna Pazdur1 • Aleksander Sanko4 ABSTRACT. Oxbow lake deposits of the Neris River at the Valakupiai site in Vilnius (Lithuania) have been studied by dif- ferent methods including radiocarbon dating. A timescale was attained for the development of the oxbow lake and climatic events recorded in the sediments. 14C dates obtained for 24 samples cover the range 990–6500 BP (AD 580 to 5600 BC). Medieval human activity was found in the upper part of the sediments. Mollusk fauna found in the basal part of the terrace indicate contact between people living in the Baltic and the Black Sea basins. Mean rates were calculated for erosion of the river and for accumulation during the formation of the first terrace. INTRODUCTION This work presents the results of radiocarbon dating of samples collected at the Valakupiai site, near Vilnius in eastern Lithuania (54°43′58″N, 25°18′33″E; 98.5 m asl) (Figure 1). Special attention was paid to the remnant oxbow lake in the Neris River valley and to the lake-bog deposits filling it. Detailed study of the deposits delivered specific information that enabled paleoecological recon- struction of the site, as well as a description of the geochronological evolution of the oxbow lake and accompanying climatic events. -
Trace Fossils and Substrates of the Terminal Proterozoic–Cambrian Transition: Implications for the Record of Early Bilaterians and Sediment Mixing
Trace fossils and substrates of the terminal Proterozoic–Cambrian transition: Implications for the record of early bilaterians and sediment mixing Mary L. Droser*†,So¨ ren Jensen*, and James G. Gehling‡ *Department of Earth Sciences, University of California, Riverside, CA 92521; and ‡South Australian Museum, Division of Natural Sciences, North Terrace, Adelaide 5000, South Australia, Australia Edited by James W. Valentine, University of California, Berkeley, CA, and approved August 16, 2002 (received for review May 29, 2002) The trace fossil record is important in determining the timing of the appearance of bilaterian animals. A conservative estimate puts this time at Ϸ555 million years ago. The preservational potential of traces made close to the sediment–water interface is crucial to detecting early benthic activity. Our studies on earliest Cambrian sediments suggest that shallow tiers were preserved to a greater extent than typical for most of the Phanerozoic, which can be attributed both directly and indirectly to the low levels of sediment mixing. The low levels of sediment mixing meant that thin event beds were preserved. The shallow depth of sediment mixing also meant that muddy sediments were firm close to the sediment–water interface, increasing the likelihood of recording shallow-tier trace fossils in muddy sed- iments. Overall, trace fossils can provide a sound record of the onset of bilaterian benthic activity. he appearance and subsequent diversification of bilaterian Tanimals is a topic of current controversy (refs. 1–7; Fig. 1). Three principal sources of evidence exist: body fossils, trace fossils (trails, tracks, and burrows of animal activity recorded in the sedimentary record), and divergence times calculated by means of a molecular ‘‘clock.’’ The body fossil record indicates a geologically rapid diversification of bilaterian animals not much earlier than the Precambrian–Cambrian boundary, the so-called Cambrian explosion. -
Overkill, Glacial History, and the Extinction of North America's Ice Age Megafauna
PERSPECTIVE Overkill, glacial history, and the extinction of North America’s Ice Age megafauna PERSPECTIVE David J. Meltzera,1 Edited by Richard G. Klein, Stanford University, Stanford, CA, and approved September 23, 2020 (received for review July 21, 2020) The end of the Pleistocene in North America saw the extinction of 38 genera of mostly large mammals. As their disappearance seemingly coincided with the arrival of people in the Americas, their extinction is often attributed to human overkill, notwithstanding a dearth of archaeological evidence of human predation. Moreover, this period saw the extinction of other species, along with significant changes in many surviving taxa, suggesting a broader cause, notably, the ecological upheaval that occurred as Earth shifted from a glacial to an interglacial climate. But, overkill advocates ask, if extinctions were due to climate changes, why did these large mammals survive previous glacial−interglacial transitions, only to vanish at the one when human hunters were present? This question rests on two assumptions: that pre- vious glacial−interglacial transitions were similar to the end of the Pleistocene, and that the large mammal genera survived unchanged over multiple such cycles. Neither is demonstrably correct. Resolving the cause of large mammal extinctions requires greater knowledge of individual species’ histories and their adaptive tolerances, a fuller understanding of how past climatic and ecological changes impacted those animals and their biotic communities, and what changes occurred at the Pleistocene−Holocene boundary that might have led to those genera going extinct at that time. Then we will be able to ascertain whether the sole ecologically significant difference between previous glacial−interglacial transitions and the very last one was a human presence. -
Convective Isolation of Hadean Mantle Reservoirs Through Archean Time
Convective isolation of Hadean mantle reservoirs through Archean time Jonas Tuscha,1, Carsten Münkera, Eric Hasenstaba, Mike Jansena, Chris S. Mariena, Florian Kurzweila, Martin J. Van Kranendonkb,c, Hugh Smithiesd, Wolfgang Maiere, and Dieter Garbe-Schönbergf aInstitut für Geologie und Mineralogie, Universität zu Köln, 50674 Köln, Germany; bSchool of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, NSW 2052, Australia; cAustralian Center for Astrobiology, The University of New South Wales, Kensington, NSW 2052, Australia; dDepartment of Mines, Industry Regulations and Safety, Geological Survey of Western Australia, East Perth, WA 6004, Australia; eSchool of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, United Kingdom; and fInstitut für Geowissenschaften, Universität zu Kiel, 24118 Kiel, Germany Edited by Richard W. Carlson, Carnegie Institution for Science, Washington, DC, and approved November 18, 2020 (received for review June 19, 2020) Although Earth has a convecting mantle, ancient mantle reservoirs anomalies in Eoarchean rocks was interpreted as evidence that that formed within the first 100 Ma of Earth’s history (Hadean these rocks lacked a late veneer component (5). Conversely, the Eon) appear to have been preserved through geologic time. Evi- presence of some late accreted material is required to explain the dence for this is based on small anomalies of isotopes such as elevated abundances of highly siderophile elements (HSEs) in 182W, 142Nd, and 129Xe that are decay products of short-lived nu- Earth’s modern silicate mantle (9). Notably, some Archean rocks clide systems. Studies of such short-lived isotopes have typically with apparent pre-late veneer like 182W isotope excesses were focused on geological units with a limited age range and therefore shown to display HSE concentrations that are indistinguishable only provide snapshots of regional mantle heterogeneities. -
Boreal Region European Commission Environment Directorate General
Natura 2000 in the Boreal Region European Commission Environment Directorate General Author: Kerstin Sundseth, Ecosystems LTD, Brussels. Managing editor: Susanne Wegefelt, European Commission, Nature and Biodiversity Unit B2, B-1049 Brussels. Contributors: Anja Finne, John Houston, Mats Eriksson. Acknowledgements: Our thanks to the European Topic Centre on Biological Diversity and the Catholic University of Leuven, Division SADL for providing the data for the tables and maps Graphic design: NatureBureau International Photo credits: Front cover: Lapland, Finland; Jorma Luhta; INSETS TOP TO BOTTOM Jorma Luhta, Kerstin Sundseth, Tommi Päivinen, Coastal Meadow management LIFE- Nature project. Back cover: Baltic Coast, Latvia; Kerstin Sundseth Additional information on Natura 2000 is available from http://ec.europa.eu/environment/nature Europe Direct is a service to help you find answers Contents to your questions about the European Union New freephone number (*): 00 800 6 7 8 9 10 11 The Boreal Region – land of trees and water ................ p. 3 (*) Certain mobile telephone operators do not allow access to 00 800 numbers or these calls may be billed. Natura 2000 habitat types in the Boreal Region .......... p. 5 Map of Natura 2000 sites in the Boreal Region ..............p. 6 Information on the European Union is available on the Natura 2000 species in the Boreal Region ........................p. 8 Internet (http://ec.europa.eu). Management issues in the Boreal Region ........................p. 10 Luxembourg: Office for Official Publications of the European Communities, 2009 © European Communities, 2009 2009 – 12 pp – 21 x 29.7 cm ISBN 978-92-79-11726-8 DOI 10.2779/84505 Reproduction is authorised provided the source is acknowledged.