Neoproterozoic Snowball Earth, Before and After
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
UMNP Mountains Manual 2017
Mountain Adventures Manual utahmasternaturalist.org June 2017 UMN/Manual/2017-03pr Welcome to Utah Master Naturalist! Utah Master Naturalist was developed to help you initiate or continue your own personal journey to increase your understanding of, and appreciation for, Utah’s amazing natural world. We will explore and learn aBout the major ecosystems of Utah, the plant and animal communities that depend upon those systems, and our role in shaping our past, in determining our future, and as stewards of the land. Utah Master Naturalist is a certification program developed By Utah State University Extension with the partnership of more than 25 other organizations in Utah. The mission of Utah Master Naturalist is to develop well-informed volunteers and professionals who provide education, outreach, and service promoting stewardship of natural resources within their communities. Our goal, then, is to assist you in assisting others to develop a greater appreciation and respect for Utah’s Beautiful natural world. “When we see the land as a community to which we belong, we may begin to use it with love and respect.” - Aldo Leopold Participating in a Utah Master Naturalist course provides each of us opportunities to learn not only from the instructors and guest speaKers, But also from each other. We each arrive at a Utah Master Naturalist course with our own rich collection of knowledge and experiences, and we have a unique opportunity to share that Knowledge with each other. This helps us learn and grow not just as individuals, but together as a group with the understanding that there is always more to learn, and more to share. -
The Huronian Glaciation
Brasier, A.T., Martin, A.P., Melezhik, V.A., Prave, A.R., Condon, D.J., and Fallick, A.E. (2013) Earth's earliest global glaciation? Carbonate geochemistry and geochronology of the Polisarka Sedimentary Formation, Kola Peninsula, Russia. Precambrian Research, 235 . pp. 278-294. ISSN 0301-9268 Copyright © 2013 Elsevier B.V. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge Content must not be changed in any way or reproduced in any format or medium without the formal permission of the copyright holder(s) When referring to this work, full bibliographic details must be given http://eprints.gla.ac.uk/84700 Deposited on: 29 August 2013 Enlighten – Research publications by members of the University of Glasgow http://eprints.gla.ac.uk 1 Earth’s earliest global glaciation? Carbonate geochemistry and geochronology of the 2 Polisarka Sedimentary Formation, Kola Peninsula, Russia 3 4 A.T. Brasier1,6*, A.P. Martin2+, V.A. Melezhik3,4, A.R. Prave5, D.J. Condon2, A.E. Fallick6 and 5 FAR-DEEP Scientists 6 7 1 Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV 8 Amsterdam 9 2 NERC Isotope Geosciences Laboratory, British Geological Survey, Environmental Science 10 Centre, Keyworth, UK. NG12 5GG 11 3 Geological Survey of Norway, Postboks 6315 Slupen, NO-7491 Trondheim, Norway 12 4 Centre for Geobiology, University of Bergen, Postboks 7803, NO-5020 Bergen, Norway 13 5 Department of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 14 9AL, Scotland, UK 15 6 Scottish Universities Environmental Research Centre, Rankine Avenue, East Kilbride, Scotland. -
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. -
Timeline of the Evolutionary History of Life
Timeline of the evolutionary history of life This timeline of the evolutionary history of life represents the current scientific theory Life timeline Ice Ages outlining the major events during the 0 — Primates Quater nary Flowers ←Earliest apes development of life on planet Earth. In P Birds h Mammals – Plants Dinosaurs biology, evolution is any change across Karo o a n ← Andean Tetrapoda successive generations in the heritable -50 0 — e Arthropods Molluscs r ←Cambrian explosion characteristics of biological populations. o ← Cryoge nian Ediacara biota – z ← Evolutionary processes give rise to diversity o Earliest animals ←Earliest plants at every level of biological organization, i Multicellular -1000 — c from kingdoms to species, and individual life ←Sexual reproduction organisms and molecules, such as DNA and – P proteins. The similarities between all present r -1500 — o day organisms indicate the presence of a t – e common ancestor from which all known r Eukaryotes o species, living and extinct, have diverged -2000 — z o through the process of evolution. More than i Huron ian – c 99 percent of all species, amounting to over ←Oxygen crisis [1] five billion species, that ever lived on -2500 — ←Atmospheric oxygen Earth are estimated to be extinct.[2][3] Estimates on the number of Earth's current – Photosynthesis Pong ola species range from 10 million to 14 -3000 — A million,[4] of which about 1.2 million have r c been documented and over 86 percent have – h [5] e not yet been described. However, a May a -3500 — n ←Earliest oxygen 2016 -
Complete Meeting Packet
PUBLIC MEETING NOTICE Nevada Land Management Task Force (Established Pursuant to Assembly Bill 227 enacted in the 2013 Legislative Session) August 16, 2013, 1:00 p.m. Eureka Opera House 31 S. Main St. Eureka, NV 89316 AGENDA Some Task Force members may attend via telephone from other locations. Items on the agenda may be taken out of order. The Task Force may combine two or more agenda items for consideration. The Task Force may remove an item from the agenda or delay discussion relating to an item on the agenda at any time. Call to Order, Roll Call 1. Public Comment. Please Limit Comments to 3 Minutes 2. Approval of Agenda. For Possible Action. 3. Approval of the Minutes of the June 28, 2013 Meeting of the Nevada Land Management Task Force. For Possible Action. (Attachment) 4. Overview of Legislation in Other Western States Regarding the Transfer of Public Lands. 5. Presentation on Studies Commissioned by Eureka County in 1994 and 1996 on Public Lands Transfer Issues. 6. Initial Discussion on Potential Lands to be Included in a Transfer of Public Lands from the Federal Government to Nevada. (Attachment) 7. Initial Discussion of Cost and Revenue Implications of the Transfer of Public Lands to Nevada. (Attachment) 8. Initial Discussion on Transferring Multiple Uses, Including but not Limited to Outdoor Recreation, Mining and Prospecting, Timber, Grazing, and Fish and Wildlife Purposes, with the Transfer of Public Lands. 9. Initial Discussion on Which Public Lands, if Transferred to State Ownership, Should be Sold or Exchanged into the Private Sector and How Should the Sales Take Place? 10. -
Neoproterozoic Glaciations in a Revised Global Palaeogeography from the Breakup of Rodinia to the Assembly of Gondwanaland
Sedimentary Geology 294 (2013) 219–232 Contents lists available at SciVerse ScienceDirect Sedimentary Geology journal homepage: www.elsevier.com/locate/sedgeo Invited review Neoproterozoic glaciations in a revised global palaeogeography from the breakup of Rodinia to the assembly of Gondwanaland Zheng-Xiang Li a,b,⁎, David A.D. Evans b, Galen P. Halverson c,d a ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) and The Institute for Geoscience Research (TIGeR), Department of Applied Geology, Curtin University, GPO Box U1987, Perth, WA 6845, Australia b Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA c Earth & Planetary Sciences/GEOTOP, McGill University, 3450 University St., Montreal, Quebec H3A0E8, Canada d Tectonics, Resources and Exploration (TRaX), School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Australia article info abstract Article history: This review paper presents a set of revised global palaeogeographic maps for the 825–540 Ma interval using Received 6 January 2013 the latest palaeomagnetic data, along with lithological information for Neoproterozoic sedimentary basins. Received in revised form 24 May 2013 These maps form the basis for an examination of the relationships between known glacial deposits, Accepted 28 May 2013 palaeolatitude, positions of continental rifting, relative sea-level changes, and major global tectonic events Available online 5 June 2013 such as supercontinent assembly, breakup and superplume events. This analysis reveals several fundamental ’ Editor: J. Knight palaeogeographic features that will help inform and constrain models for Earth s climatic and geodynamic evolution during the Neoproterozoic. First, glacial deposits at or near sea level appear to extend from high Keywords: latitudes into the deep tropics for all three Neoproterozoic ice ages (Sturtian, Marinoan and Gaskiers), al- Neoproterozoic though the Gaskiers interval remains very poorly constrained in both palaeomagnetic data and global Rodinia lithostratigraphic correlations. -
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. -
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. -
The History of Ice on Earth by Michael Marshall
The history of ice on Earth By Michael Marshall Primitive humans, clad in animal skins, trekking across vast expanses of ice in a desperate search to find food. That’s the image that comes to mind when most of us think about an ice age. But in fact there have been many ice ages, most of them long before humans made their first appearance. And the familiar picture of an ice age is of a comparatively mild one: others were so severe that the entire Earth froze over, for tens or even hundreds of millions of years. In fact, the planet seems to have three main settings: “greenhouse”, when tropical temperatures extend to the polesand there are no ice sheets at all; “icehouse”, when there is some permanent ice, although its extent varies greatly; and “snowball”, in which the planet’s entire surface is frozen over. Why the ice periodically advances – and why it retreats again – is a mystery that glaciologists have only just started to unravel. Here’s our recap of all the back and forth they’re trying to explain. Snowball Earth 2.4 to 2.1 billion years ago The Huronian glaciation is the oldest ice age we know about. The Earth was just over 2 billion years old, and home only to unicellular life-forms. The early stages of the Huronian, from 2.4 to 2.3 billion years ago, seem to have been particularly severe, with the entire planet frozen over in the first “snowball Earth”. This may have been triggered by a 250-million-year lull in volcanic activity, which would have meant less carbon dioxide being pumped into the atmosphere, and a reduced greenhouse effect. -
CO2, Hothouse and Snowball Earth
CO2, Hothouse and Snowball Earth Gareth E. Roberts Department of Mathematics and Computer Science College of the Holy Cross Worcester, MA, USA Mathematical Models MATH 303 Fall 2018 November 12 and 14, 2018 Roberts (Holy Cross) CO2, Hothouse and Snowball Earth Mathematical Models 1 / 42 Lecture Outline The Greenhouse Effect The Keeling Curve and the Earth’s climate history Consequences of Global Warming The long- and short-term carbon cycles and silicate weathering The Snowball Earth hypothesis Roberts (Holy Cross) CO2, Hothouse and Snowball Earth Mathematical Models 2 / 42 Chapter 1 Historical Overview of Climate Change Science Frequently Asked Question 1.3 What is the Greenhouse Effect? The Sun powers Earth’s climate, radiating energy at very short Earth’s natural greenhouse effect makes life as we know it pos- wavelengths, predominately in the visible or near-visible (e.g., ul- sible. However, human activities, primarily the burning of fossil traviolet) part of the spectrum. Roughly one-third of the solar fuels and clearing of forests, have greatly intensifi ed the natural energy that reaches the top of Earth’s atmosphere is refl ected di- greenhouse effect, causing global warming. rectly back to space. The remaining two-thirds is absorbed by the The two most abundant gases in the atmosphere, nitrogen surface and, to a lesser extent, by the atmosphere. To balance the (comprising 78% of the dry atmosphere) and oxygen (comprising absorbed incoming energy, the Earth must, on average, radiate the 21%), exert almost no greenhouse effect. Instead, the greenhouse same amount of energy back to space. Because the Earth is much effect comes from molecules that are more complex and much less colder than the Sun, it radiates at much longer wavelengths, pri- common. -
(Silurian) Anoxic Palaeo-Depressions at the Western Margin of the Murzuq Basin (Southwest Libya), Based on Gamma-Ray Spectrometry in Surface Exposures
GeoArabia, Vol. 11, No. 3, 2006 Gulf PetroLink, Bahrain Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures Nuri Fello, Sebastian Lüning, Petr Štorch and Jonathan Redfern ABSTRACT Following the melting of the Gondwanan icecap and the resulting postglacial sea- level rise, organic-rich shales were deposited in shelfal palaeo-depressions across North Africa and Arabia during the latest Ordovician to earliest Silurian. The unit is absent on palaeohighs that were flooded only later when the anoxic event had already ended. The regional distribution of the Silurian black shale is now well-known for the subsurface of the central parts of the Murzuq Basin, in Libya, where many exploration wells have been drilled and where the shale represents the main hydrocarbon source rock. On well logs, the Silurian black shale is easily recognisable due to increased uranium concentrations and, therefore, elevated gamma-ray values. The uranium in the shales “precipitated” under oxygen- reduced conditions and generally a linear relationship between uranium and organic content is developed. The distribution of the Silurian organic-rich shales in the outcrop belts surrounding the Murzuq Basin has been long unknown because Saharan surface weathering has commonly destroyed the organic matter and black colour of the shales, making it complicated to identify the previously organic-rich unit in the field. In an attempt to distinguish (previously) organic-rich from organically lean shales at outcrop, seven sections that straddle the Ordovician-Silurian boundary were measured by portable gamma-ray spectrometer along the outcrops of the western margin of the Murzuq Basin. -
Use Map Motor Vehicle Picture Here
! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! United States Department of Agriculture of Department States United ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ) ! ! 480000 490000 500000 ! 510000 ! ! ! ! ! ! 111°15'0"W 111°7'30"W 111°0'0"W ) ! 110°52'30"W ! ! ! ! ! ! ! Forest Service Forest ! ! ! ! ! ! ! ! ! ! ! ! ! ! PURPOSE AND CONTENTS ! ! ! ! 22 19 20 21 22 ! 23 24 19 20 21 ! ! 21 ! ! ! ! 20 ! ! ! ! Legend 19 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Utah 2021 Utah ! ! 4 ! Roads Open to Highway Legal Vehicles Kamas ! ! 5 OF THIS MAP !! 6 ! ! ! ! Roads Open to All Vehicles ! ! The designations shown on this motor vehicle use map ! ! 6 ! E ! 5 ! America's Great Outdoors Great America's 3 ! 1 ! v 0 ! Trails Open to All Vehicles a 3 (MVUM) were made by the responsible official pursuant to 36 n ! s t CFR 212.51; are effective as of the date on the front cover of Trails Open to Vehicles 50" or Less in Width 26 25 30 29 28 27 26 25 K o 27 26 29 28 27 30 29 28 27 26 4 25 30 29 28 30 a n 1 this MVUM; and will remain in effect until superceded by next m 1 " Trails Open to Wheeled Vehicles a 9 SULPHUR Picture Here Picture T.. 1 N .. ,, R ..77EE .. s T.. 1 N .. ,, R .. 1 0 E .. SILKS year's MVUM. 50" or Less in Width HOLIDAY BASIN ! ! ! ! ! ! ! Trails Open to Motorcyles Only T.. 1 N .. ,, R .. 8 E .. PARK T.. 1 N .. ,, R .. 9 E .. ASPEN Hell ! ! ! Special Vehicle Designation (See Table) ! ACRES ! ! ! ! ! Hole Lake ! ! 0 ! ! ! 35 36 ! 31 34 ! Put 35 36