Stromatolites: Biogenicity, Biosignatures, and Bioconfusion
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Pillow Basalts from the Mount Ada Basalt, Warrawoona Group, Pilbara Craton: Implications for the Initiation of Granite-Greenstone Terrains D
Goldschmidt2015 Abstracts Pillow basalts from the Mount Ada basalt, Warrawoona group, Pilbara Craton: Implications for the initiation of granite-greenstone terrains D. T. MURPHY1*, J. TROFIMOVS1, R. A. HEPPLE1, D. WIEMER1, A. I. S. KEMP2 AND A. H. HICKMAN3 1Earth, Environmental and Biological Sciences, Queensland University of Technology, 4001, Australia (correspondence: [email protected]) 2School of Earth and Environment, The University of Western Australia, 6009, Australia 3Department of Mines and Petroleum, Western Australia The Pilbara Craton represents the archetypal Archean granite-greenstone terrain in which mafic volcanic dominated supercrustals are intruded by granitic domes. This crustal morphology reflects distinct tectonic settings that formed in a hotter early Earth. The ambient temperature in the Paleoarchean mantle is estimated to be 1600oC [1] and corresponds with the liquidus temperature of Barberton komatiites [2]. In the Paleoarchean mantle a pyrolite composition at depths of less than 100 km is expected to melt and generate ultramafic magmas. Here we present volcanology, petrology and geochemistry data of well-preserved basaltic lavas ascribed to the Mount Ada Basalt, Warrawoona Group from the Doolena Gap Greenstone Belt. The Mount Ada Basalt was coeval with the Callina plutonic event that marks the initiation of dome formation in the Pilbara Craton [3]. The Doolena Gap sequence is exclusively pillow basalts with MgO < 10%. Isotopically the basalts are indistinguishable from contemporary non-chondritic Bulk Earth (εNd, 1.0 ± 0.2 and εHf, 2.3 ± 0.2). Here we address the implications of Paleoarchean basalts with MgO% < 10 derived from melting of a source indistinguishable from non-chondritic Bulk Silicate Earth to the initiation and subsequent evolution of the Pilbara Craton. -
Thomas Spring Thesis (PDF 7MB)
RECONSTRUCTION OF THE PHYSICAL VOLCANOLOGICAL PROCESSES AND PETROGENESIS OF THE 3.5GA WARRAWOONA GROUP PILLOW BASALT OF THE WARRALONG GREENSTONE BELT, PILBARA CRATON WESTERN AUSTRALIA Thomas Frederick David Spring Bachelor of Applied Science (Geology) Submitted in fulfilment of the requirements for the degree of Master of Applied Science (Geoscience) School of Earth, Environment and Biological Science Faculty of Science and Engineering Queensland University of Technology 2017 Abstract The formation of Earth’s continental crust initiated in the early Archean and has continued to the present day. In the early Archean, the Earth was substantially hotter than the present day leading to dramatically different tectonic processes. Early Archean tectonic processes have to be inferred from the rare well-preserved remnants of Archean crust. Models for the formation of Archean crust include large scale mantle melting associated with mantle plumes to generate thick basaltic to ultramafic crust. This crust than undergoes partial melting and internal differentiation to more felsic compositions. The Pilbara craton provides an ideal area for research into the Archean crust, with some of Earth oldest crust being preserved in relatively low strain and low metamorphosed greenstone belts. The volcanic cycles preserved in the greenstone belts of the Paleoarchean East Pilbara Terrane of the Pilbara craton represent the type example of plume-derived volcanism in the early Earth. Here I investigate the lithostratigraphy, volcanology and depositional environment of a volcanic and sedimentary succession ascribed to the Warrawoona group of the East Pilbara Supergroup from the Eastern Warralong Greenstone belt of the East Pilbara Terrane. In addition, I investigate the petrogenesis of well-preserved basaltic samples from the pillow basalt sequence ascribed to the Mt Ada Basalts in the study area. -
Stromatolites
Stromatolites What is a stromatolite? A stromatolite (literally, ‘layered rock’) is a solid structure created by single-celled microbes called cyanobacteria (blue-green algae). The cyanobacteria form colonies and trap sediment with their sticky surface coatings. The trapped sediment reacts to calcium carbonate in the water to form limestone. These limestone deposits build up very slowly – it can take a stromatolite 100 years to grow 5 cm. A 1 m-high stromatolite might be 2,000 years old! Where are they found? Shark Bay’s stromatolites are found around the shallows of Hamelin Pool , located in the southern part of the eastern bay. Between 4,000 to 6,000 years ago a massive seagrass bank called the Fauré Sill began to block tidal flow into Hamelin Pool, causing the water to become extremely concentrated, or hypersaline. The water in Hamelin Pool is twice as salty as water in the open ocean! Animals that would normally graze on algae, such as chitons and snails, cannot survive in these conditions. Around 3,000 years ago cyanobacteria started flourishing, forming stromatolites much as they did billions of years ago. More than 50 species of cyanobacteria live in Hamelin Pool. What do they look like? Stromatolites look like a cross between a cauliflower and a rock. However, unlike rocks they are actually alive – each stromatolite has a top surface layer teeming with living, active cyanobacteria. At least 3,000 million cyanobacteria can fit in 1 m2! Because cyanobacteria are plants, they photosynthesise their energy from the sun. A by-product of photosynthesis is oxygen, and if you look very carefully you may see the stromatolites gently ‘fizzing’ as tiny bubbles of oxygen are released by the cyanobacteria into the water. -
What Doomed the Stromatolites? SCIENTISTS FIND KEY CLUE to Ancient ENIGMA by Cherie Winner
Microbes What Doomed the Stromatolites? SCIENTISTS FIND KEY CLUE TO ANCIENT ENIGMA by Cherie Winner Virginia Edgcomb/WHOI Rocky formations like these, called stromatolites, dominated coastal areas billions of years ago. Now they exist in only a few locations. bout a billion years before the dinosaurs became extinct, Forams are abundant in present-day ocean sediments, where stromatolites roamed the Earth until they mysteriously they use fingerlike extensions called pseudopods to engulf prey disappeared. Well, not roamed exactly. and to explore their surroundings. In the process, their pseudo- Stromatolites (“layered rocks”) are rocky structures pods churn the sediments on a microscopic scale. made by photosynthetic cyanobacteria. The microbes Living stromatolites can still be found today, in limited and secrete sticky compounds that bind together sediment widely scattered locales, as if a few velociraptors still roamed in grains,A creating a mineral “microfabric” that accumulates in fine remote valleys. Bernhard, Edgcomb, and colleagues looked for layers. Massive formations of stromatolites showed up along foraminifera in living stromatolite and thrombolite formations shorelines all over the world about 3.5 billion years ago. They from Highborne Cay in the Bahamas. Using microscope and were the earliest visible manifestation of life on Earth and domi- RNA sequencing techniques, they found forams in both—and nated the scene for more than two billion years. thrombolites were especially rich in the kinds of forams that “They were one of the earliest examples of the intimate were probably the first foraminifera to evolve on Earth. connection between biology—living things—and geology— “The timing of their appearance corresponds with the the structure of the Earth itself,” said Joan decline of layered stromatolites and the Bernhard, a geobiologist at Woods Hole appearance of thrombolites in the fossil re- Oceanographic Institution (WHOI). -
2011 Fall Paper Session Program And
Rochester Academy of Science Fall 2011 Scientific Papers Day Saturday, October 29, 2011 Hosted by: Monroe County Community College and the Departments of Biology, Chemistry and Geosciences, and Engineering Science and Physics Table of Contents Page Schedule of the Day 3 Session Schedules Session I: Agriculture, Anthropology & New Approaches 5 Session II: Phylogeny, Ecology & Paleontology 6 Session III: Ecology 7 Session IV: Meteorology, Physics & Astronomy 8 Session V: Chemistry I 9 Session VI: Chemistry II 10 List of Posters 11 All Abstracts 21 Acknowledgements 91 2 Rochester Academy of Science Fall 2011 Scientific Papers Day Saturday, October 29, 2011 Hosted by: Monroe County Community College and the Departments of Biology, Chemistry and Geosciences, and Engineering Science and Physics 8:00 am Registration Gilman Lounge, Flynn Campus Center 8:00 – 9:00 am Coffee & Refreshments Gilman Lounge, Flynn Campus Center 9:00 – 11:00 am Oral Presentations Session I: Agriculture, Anthropology & New Approaches 12-209 Session II: Phylogeny, Ecology & Paleontology 12-203 Session III: Ecology 12-207 Session IV: Meteorology, Physics & Astronomy 12-215 Session V: Chemistry I 12-211 Session VI: Chemistry II 12-213 11:00 am – 12:00 pm Poster Session Forum (3-130) 12:00 pm Luncheon Monroe A and B, Flynn Campus Center 1:00 pm Key Note Speaker Monroe A and B, Flynn Campus Center Disappearing Ice! Mass Loss and Dynamics of the Greenland Ice Sheet Dr. Beata Csatho Department of Geology, University of Buffalo 3 4 Oral Presentations Session I: Agriculture, -
12.007 Geobiology Spring 2009
MIT OpenCourseWare http://ocw.mit.edu 12.007 Geobiology Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Geobiology 2009 Lecture 10 The Antiquity of Life on Earth Homework #5 Topics (choose 1): Describe criteria for biogenicity in microscopic fossils. How do the oldest describes fossils compare? Use this to argue one side of the Brasier-Schopf debate OR What are stromatolites; where are they found and how are they formed? Articulate the two sides of the debate on antiquity and biogenicity. Up to 4 pages, including figures. Due 3/31/2009 Need to know • How C and S- isotopic data in rocks are informative about the advent and antiquity of biogeochemical cycles • Morphological remains and the antiquity of life; how do we weigh the evidence? • Indicators of changes in atmospheric pO2 • A general view of the course of oxygenation of the atm-ocean system Readings for this lecture Schopf J.W. et al., (2002) Laser Raman Imagery of Earth’s earliest fossils. Nature 416, 73. Brasier M.D. et al., (2002) Questioning the evidence for Earth’s oldest fossils. Nature 416, 76. Garcia-Ruiz J.M., Hyde S.T., Carnerup A. M. , Christy v, Van Kranendonk M. J. and Welham N. J. (2003) Self-Assembled Silica-Carbonate Structures and Detection of Ancient Microfossils Science 302, 1194-7. Hofmann, H.J., Grey, K., Hickman, A.H., and Thorpe, R. 1999. Origin of 3.45 Ga coniform stromatolites in Warrawoona Group, Western Australia. Geological Society of America, Bulletin, v. 111 (8), p. -
Carbon Cycling and Calcification in Hypersaline Microbial Mats
Carbon cycling and calcification in hypersaline microbial mats Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften - Dr. rer. nat.- Dem Fachbereich Biologie/Chemie der Universität Bremen vorgelegt von Rebecca Ludwig Bremen März 2004 Die vorliegende Arbeit wurde in der Zeit von Oktober 2000 bis März 2004 am Max-Planck-Institut für marine Mikrobiologie in Bremen angefertigt. Gutachter Prof. Dr. Bo Barker Jørgensen Prof. Dr. Gunter O. Kirst Prüfer Prof. Dr. Friederike Koenig Dr. Henk M. Jonkers Tag des Promotionskolloqiums: 14. Mai 2004 Table of contents Table of contents Thesis outline v 1 Introduction 1 Prologue 3 Carbon cycle in microbial mats: Organisms and metabolism 8 Gradients and adaptations to diel changes 17 Calcification 20 Principles and applications of microsensors 22 Sampling/study sites 28 2 Structure and function of Chiprana mats 37 Structural and functional analysis of a microbial mat ecosystem from a unique permanent hypersaline inland lake: ‘La Salada de Chiprana’ (NE Spain) 3 Rate limitation in microbial mats 71 Limitation of oxygenic photosynthesis and respiration by phosphate and organic nitrogen in a hypersaline mat: A microsensor study 4 Effect of salinity on benthic photosynthesis 89 Reduced gas diffusivity and solubility limit metabolic rates in benthic phototrophs at high salinities 5 Calcification mechanism in a microbial mat 109 Photosynthesis controlled calcification in a hypersaline microbial mat 6 Stromatolite calcification and bioerosion 127 Balance between microbial calcification and metazoan bioerosion in modern stromatolitic oncolites Discussion 145 Summary 151 Zusammenfassung 153 Appendix 155 Danksagung 155 List of publications 157 iii Outline Thesis outline Five manuscripts are included in this thesis that investigate the carbon cycle in microbial mats with a special emphasis on community carbon flow and mechanisms of microbial calcification. -
Lake Clifton
Advice to the Minister for the Environment, Heritage and the Arts from the Threatened Species Scientific Committee (the Committee) on an Amendment to the List of Threatened Ecological Communities under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) 1. Name of the ecological community Thrombolite (microbialite) Community of a Coastal Brackish Lake (Lake Clifton) This advice follows the assessment of information provided by a public nomination to include the “Thrombolite (microbial) Community of a Coastal Brackish Lake (Lake Clifton)” in the critically endangered category of the list of threatened ecological communities under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). This name is consistent with the name used for this ecological community in Western Australia, although a reference to stromatolites which appears in the Western Australian title has been omitted for the sake of clarity. 2. Public Consultation The nomination was made available for public exhibition and comment for a minimum 30 business days. In addition, detailed consultation with experts on the ecological community was undertaken. The Committee also had regard to all public and expert comment that was relevant to the consideration of the ecological community. 3. Summary of conservation assessment by the Committee The Committee provides the following assessment of the appropriateness of the ecological community’s inclusion in the EPBC Act list of threatened ecological communities. The Committee judges that the ecological community has been demonstrated to have met sufficient elements of Criterion 2 to make it eligible for listing as critically endangered. The Committee judges that the ecological community has been demonstrated to have met sufficient elements of Criterion 3 to make it eligible for listing as critically endangered. -
Geology Final.Indb
Paleontology of the Neoproterozoic Uinta Mountain Group Robin M. Nagy* and Susannah M. Porter* ABSTRACT Sedimentary rocks of the Uinta Mountain Group (northeastern Utah) preserve fossils deposited in a marine setting during middle Neoproterozoic time. Although well preserved, species diversity is much lower than many other midddle Neoproterozoic siliciclastic deposits. Microfossil assemblages are mostly limited to Leiosphaeridia sp., Bavlinella faveolata, and fi laments. Diverse ornamented acritarchs, vase- shaped microfossils, and the macroscopic compression fossil Chuaria circularis, also occur, but are much more rare. Although the Uinta Mountain Group does not preserve as wide a range of facies as other middle Neoproterozoic units – the unit is carbonate-free – it is unlikely that preservation alone can account for its relatively limited fossil diversity. Rather, the Uinta Mountain Group likely records deposition in an environment that was inimical to most eukaryotes. INTRODUCTION own (see table 2). We find that although the UMG is fossiliferous throughout its stratigraphic and The Uinta Mountain Group (UMG) is one geographic range, (appendix A) fossil assemblages of several western North American successions are, for the most part, taxonomically depauperate, that provide a glimpse of middle Neoproterozoic limited to just one or a few morphologically simple life (Link and others, 1993). Other successions species. This probably reflects, at least in part, the from this region have yielded important insight limited range of taphonomic windows preserved into this critical interval, including the earliest in the UMG, but also suggests that much of the evidence for eukaryotic biomineralization UMG was deposited in an environment inimical to (Horodyski and Mankiewicz, 1990; Porter and high species diversity. -
Open Kosei.Pdf
The Pennsylvania State University The Graduate School Department of Geosciences GEOCHEMISTRY OF ARCHEAN–PALEOPROTEROZOIC BLACK SHALES: THE EARLY EVOLUTION OF THE ATMOSPHERE, OCEANS, AND BIOSPHERE A Thesis in Geosciences by Kosei Yamaguchi Copyright 2002 Kosei Yamaguchi Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy May 2002 We approve the thesis of Kosei Yamaguchi Date of Signature ____________________________________ _______________________ Hiroshi Ohmoto Professor of Geochemistry Thesis Advisor Chair of Committee ____________________________________ _______________________ Michael A. Arthur Professor of Geosciences ____________________________________ _______________________ Lee R. Kump Professor of Geosciences ____________________________________ _______________________ Raymond G. Najjar Associate Professor of Meteorology ____________________________________ _______________________ Peter Deines Professor of Geochemistry Associate Head for Graduate Program and Research in Geosciences iii ABSTRACT When did the Earth's surface environment become oxic? The timing and mechanism of the rise of atmospheric pO2 level in the early Precambrian have been long debated but no consensus has been reached. The oxygenation of the atmosphere and oceans has significant impacts on the evolution of the biosphere and the geochemical cycles of redox-sensitive elements. In order to constrain the evolution of the atmosphere, oceans, biosphere, and geochemical cycles of elements, a systematic and multidisciplinary -
Analysis of Stromatolite Reservoir Potential Using Computed Tomography By: Grant Noennig
Analysis of Stromatolite Reservoir Potential using Computed Tomography By: Grant Noennig A thesis submitted in partial fulfillment of the requirements of the degree of Bachelor of Arts (Geology) At Gustavus Adolphus College 2016 Volumetric Analysis of Stromatolite Reservoir Potential using Computed Tomography By: Grant Noennig Under the supervision of Dr. Julie Bartley ABSTRACT Stromatolites are lithified microbial mats formed when microbes bind and trap carbonate grains or induce precipitation of carbonate material (Ahr et al., 2011). If sufficient porosity occurs within these microbialites, they have potential to contain and transmit fluids, such as petroleum. Carbonate rock accounts for more than half of the world's oil reservoirs and 40% of the world's natural gas reservoirs, but due to the complexity of fractures and matrix composing these beds, their reservoir potentials are difficult to estimate (EIA, 2013). Stromatolites from the Laney Member of the hydrocarbon-rich Green River Formation in the central United States offer an opportunity to study reservoir potential in a well-exposed succession. Most research on carbonate reservoir potential is sedimentary, stratigraphic, or petrophysical, but more complex reservoirs like stromatolites require specific techniques to determine their potential (Rezende et al., 2013). In order to determine the porosity, permeability, and pore-connectivity of this facies, samples from this location were cut into rectangular blocks and scanned using x-ray computed tomography (XRCT) at the University of Minnesota. XRCT analysis allows for the quantification of porosity and permeability values to evaluate the reservoir potential at a small scale, in three dimensions. Preliminary results indicate that Green River stromatolites are highly variable in their porosity characteristics, but some have sufficient porosity and permeability to be effective reservoir rock. -
Grain Trapping by Microbial Mats: Implications for Stromatolites
Grain trapping by microbial mats: Implications for stromatolites Frank Corsetti Department of Earth Sciences University of Southern California Rocks = Time Rocks = Environment Rocks = History of Life Stromatolite sharkbay.org Stromatolite Textbook Definition • laminated • organo-sedimentary structure • built by microbes (CCALA) Cyanobacteria Cyanobacteria microbial mat (“pond scum”) Stromatolite Textbook Definition Trapping and Binding 100 microns Stromatolite courtesy of Y. Ibarra Textbook Definition Mineral Precipitation Stromatolite Significance • Macroscopic from Microscopic Stromatolite Significance putative • Oldest fossils in the world ^ Warrawoona Fm Western Australia 3.5 Ga 2 cm Ancient Life: Greatest Hits Cambrian explosion Hadean Archean Proterozoic Phan. 4.0 3.0 2.0 1.0 0 billions of years LETTERS NATURE | Vol 457 | 5 February 2009 Masirah Bay Fm. soft-body parts, as detected in Doushantuo phosphorites19,22, is rare in ααα ααα αββ the geological record. Siliceous sponge spicules are metastable and S R C (17%) they can be difficult to isolate and identify unambiguously in clastic 26 sediments. Moreover, several orders of Demospongiae completely *** * 358 → 217 lack mineral skeletons. On the other hand, the studies of the lipid ααα ααα compositions of Porifera show a remarkable diversity of distinctive αββ C27 (21%) 13,27,28 R structures with abundance patterns aligned to phylogeny S 372 → 217 The demosponge biomarker record for the Huqf Supergroup supports the hypothesis that Metazoa first achieved ecological 1 αββ ααα ααα prominence in shallow marine waters of the Cryogenian . It has been C28 (16%) 386 → 217 proposed that Neoproterozoic sponges and rangeomorphs feeding S R on reactive dissolved or particulate marine organic matter29 may have progressively oxygenated their benthic environments as they moved ααα ααα αββ 24 C29 (39%) from shallow water into deeper waters .