Geologic Time and Earth's Biological History
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Decoupled Evolution of Soft and Hard Substrate Communities During the Cambrian Explosion and Great Ordovician Biodiversification Event
Decoupled evolution of soft and hard substrate communities during the Cambrian Explosion and Great Ordovician Biodiversification Event Luis A. Buatoisa,1, Maria G. Mánganoa, Ricardo A. Oleab, and Mark A. Wilsonc aDepartment of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E2; bEastern Energy Resources Science Center, US Geological Survey, Reston, VA 20192; and cDepartment of Geology, The College of Wooster, Wooster, OH 44691 Edited by Steven M. Holland, University of Georgia, Athens, GA, and accepted by Editorial Board Member David Jablonski May 6, 2016 (received for review November 21, 2015) Contrasts between the Cambrian Explosion (CE) and the Great shed light on the natures of both radiations. Because there is still Ordovician Biodiversification Event (GOBE) have long been recog- controversy regarding Sepkoski’s nonstandardized curves of nized. Whereas the vast majority of body plans were established Phanerozoic taxonomic diversity (13–15), a rarefaction analysis as a result of the CE, taxonomic increases during the GOBE were was performed in an attempt to standardize diversity data. The manifested at lower taxonomic levels. Assessing changes of ichno- aims of this paper are to document the contrasting ichnodiversity diversity and ichnodisparity as a result of these two evolutionary and ichnodisparity trajectories in soft and hard substrate com- events may shed light on the dynamics of both radiations. The early munities during these two evolutionary events and to discuss the Cambrian (series 1 and 2) displayed a dramatic increase in ichnodi- possible underlying causes of this decoupled evolution. versity and ichnodisparity in softground communities. In contrast to this evolutionary explosion in bioturbation structures, only a few Results Cambrian bioerosion structures are known. -
The Lithostratigraphy and Biostratigraphy of the Chalk Group (Upper Coniacian 1 to Upper Campanian) at Scratchell’S Bay and Alum Bay, Isle of Wight, UK
Manuscript Click here to view linked References The lithostratigraphy and biostratigraphy of the Chalk Group (Upper Coniacian 1 to Upper Campanian) at Scratchell’s Bay and Alum Bay, Isle of Wight, UK. 2 3 Peter Hopson1*, Andrew Farrant1, Ian Wilkinson1, Mark Woods1 , Sev Kender1 4 2 5 and Sofie Jehle , 6 7 1 British Geological Survey, Sir Kingsley Dunham Centre, Nottingham, NG12 8 5GG. 9 2 10 University of Tübingen, Sigwartstraße 10, 72074 Tübingen, Germany 11 12 * corresponding author [email protected] 13 14 Keywords: Cretaceous, Isle of Wight, Chalk, lithostratigraphy, biostratigraphy, 15 16 17 Abstract 18 19 The Scratchell‟s Bay and southern Alum Bay sections, in the extreme west of the Isle 20 21 of Wight on the Needles promontory, cover the stratigraphically highest Chalk Group 22 formations available in southern England. They are relatively inaccessible, other than 23 by boat, and despite being a virtually unbroken succession they have not received the 24 attention afforded to the Whitecliff GCR (Geological Conservation Review series) 25 site at the eastern extremity of the island. A detailed account of the lithostratigraphy 26 27 of the strata in Scratchell‟s Bay is presented and integrated with macro and micro 28 biostratigraphical results for each formation present. Comparisons are made with 29 earlier work to provide a comprehensive description of the Seaford Chalk, Newhaven 30 Chalk, Culver Chalk and Portsdown Chalk formations for the Needles promontory. 31 32 33 The strata described are correlated with those seen in the Culver Down Cliffs – 34 Whitecliff Bay at the eastern end of the island that form the Whitecliff GCR site. -
Geological Timeline
Geological Timeline In this pack you will find information and activities to help your class grasp the concept of geological time, just how old our planet is, and just how young we, as a species, are. Planet Earth is 4,600 million years old. We all know this is very old indeed, but big numbers like this are always difficult to get your head around. The activities in this pack will help your class to make visual representations of the age of the Earth to help them get to grips with the timescales involved. Important EvEnts In thE Earth’s hIstory 4600 mya (million years ago) – Planet Earth formed. Dust left over from the birth of the sun clumped together to form planet Earth. The other planets in our solar system were also formed in this way at about the same time. 4500 mya – Earth’s core and crust formed. Dense metals sank to the centre of the Earth and formed the core, while the outside layer cooled and solidified to form the Earth’s crust. 4400 mya – The Earth’s first oceans formed. Water vapour was released into the Earth’s atmosphere by volcanism. It then cooled, fell back down as rain, and formed the Earth’s first oceans. Some water may also have been brought to Earth by comets and asteroids. 3850 mya – The first life appeared on Earth. It was very simple single-celled organisms. Exactly how life first arose is a mystery. 1500 mya – Oxygen began to accumulate in the Earth’s atmosphere. Oxygen is made by cyanobacteria (blue-green algae) as a product of photosynthesis. -
In Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core) Molly F
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln ANDRILL Research and Publications Antarctic Drilling Program 2009 Significance of the Trace Fossil Zoophycos in Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core) Molly F. Miller Vanderbilt University, [email protected] Ellen A. Cowan Appalachian State University, [email protected] Simon H. H. Nielsen Florida State University Follow this and additional works at: http://digitalcommons.unl.edu/andrillrespub Part of the Oceanography Commons, and the Paleobiology Commons Miller, Molly F.; Cowan, Ellen A.; and Nielsen, Simon H. H., "Significance of the Trace Fossil Zoophycos in Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core)" (2009). ANDRILL Research and Publications. 61. http://digitalcommons.unl.edu/andrillrespub/61 This Article is brought to you for free and open access by the Antarctic Drilling Program at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in ANDRILL Research and Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in Antarctic Science 21(6) (2009), & Antarctic Science Ltd (2009), pp. 609–618; doi: 10.1017/ s0954102009002041 Copyright © 2009 Cambridge University Press Submitted July 25, 2008, accepted February 9, 2009 Significance of the trace fossil Zoophycos in Pliocene deposits, Antarctic continental margin (ANDRILL 1B drill core) Molly F. Miller,1 Ellen A. Cowan,2 and Simon H.H. Nielsen3 1. Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37235, USA 2. Department of Geology, Appalachian State University, Boone, NC 28608, USA 3. Antarctic Research Facility, Florida State University, Tallahassee FL 32306-4100, USA Corresponding author — Molly F. -
Definition of Chalk
1.1: Introduction: 1.1.1: Definition of chalk: Chalk is a soft, white, porous sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert unique to chalk) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). Chalk as seen in Cretaceous deposits of Western Europe is unusual among sedimentary limestone in the thickness of the beds. Most cliffs of chalk have very few obvious bedding planes unlike most thick sequences of limestone such as the Carboniferous Limestone or the Jurassic oolitic limestones. This presumably indicates very stable conditions over tens of millions of years. Figure (1-1): Calcium sulphate 1 "Nitzana Chalk curves" situated at Western Negev, Israel are chalk deposits formed at the Mesozoic era's Tethys Ocean Chalk has greater resistance to weathering and slumping than the clays with which it is usually associated, thus forming tall steep cliffs where chalk ridges meet the sea. Chalk hills, known as chalk downland, usually form where bands of chalk reach the surface at an angle, so forming a scarp slope. Because chalk is well jointed it can hold a large volume of ground water, providing a natural reservoir that releases water slowly through dry seasons. -
2021-2022.Pdf
UNIVERSITY OF DAYTON DAYTON OH 2021-2022 ACADEMIC CALENDAR FALL 2021 Date Event Mon, Aug 9 Degrees conferred – no ceremony Mon-Tue, Aug 16-17 New Faculty Orientation Thu, Aug 19 New Graduate Assistant Orientation Fri-Sun, Aug 20-22 New Student Welcome Weekend Fri, Aug 20 Last Day to complete registration Sat, Aug 21 President’s Welcome and New Student Convocation Mon, Aug 23 Classes begin at 8:00 AM Fri, Aug 27 Last day for late registration, change of grading options and schedules Mon, Sept 6 Labor Day – no classes Thu, Sept 9 Last day to change Second Session and full Summer Term grades Mon, Sep 13 Last day to drop classes without record Fri, Sep 17 Faculty Meeting – via Zoom at 3:30 PM Fri, Sept 24 Academic Senate Meeting – via Zoom at 3:30 PM Wed, Oct 6 Mid-Term Break begins after last class Mon, Oct 11 Classes resume at 8:00 AM Fri, Oct 15 Last day for Graduate and Doctoral students to apply for December, 2021 graduation Wed, Oct 20 First and Second Year students’ midterm progress grades due by 9:00 AM Fri, Oct 29 Academic Senate Meeting – KU Ballroom at 3:30 PM Mon, Nov 1 Last day for Undergraduate students to apply for May, 2022 graduation Mon, Nov 15 Last day to drop classes with record of W Fri, Nov 19 Academic Senate Meeting – KU Ballroom at 3:30 PM Tue, Nov 23 Thanksgiving recess begins after last class Sat, Nov 27 Saturday classes meet Mon, Nov 29 Classes resume at 8:00 AM Wed, Dec 8 Feast of the Immaculate Conception/Christmas on Campus – no classes Fri, Dec 10 Last day of classes Sat, Dec 11 Study Day Sun, Dec 12 Study Day Mon-Fri, Dec 13-17 Exams – Fall Term ends after final examination Sat, Dec 18 Diploma Exercises at 9:45 AM Tue, Dec 21 Grades due by 9:00 AM Thu, Dec 23 End of Term processing officially complete Thu, Jan 20 Last day to change Fall Term grades CHRISTMAS BREAK Date Event Sun, Dec 19 Christmas Break begins Sun, Jan 9 Christmas Break ends SPRING 2022 Date Event Fri, Jan 7 Last day to complete registration Mon, Jan 10 Classes begin at 8:00 AM. -
MARS DURING the PRE-NOACHIAN. J. C. Andrews-Hanna1 and W. B. Bottke2, 1Lunar and Planetary La- Boratory, University of Arizona
Fourth Conference on Early Mars 2017 (LPI Contrib. No. 2014) 3078.pdf MARS DURING THE PRE-NOACHIAN. J. C. Andrews-Hanna1 and W. B. Bottke2, 1Lunar and Planetary La- boratory, University of Arizona, Tucson, AZ 85721, [email protected], 2Southwest Research Institute and NASA’s SSERVI-ISET team, 1050 Walnut St., Suite 300, Boulder, CO 80302. Introduction: The surface geology of Mars appar- ing the pre-Noachian was ~10% of that during the ently dates back to the beginning of the Early Noachi- LHB. Consideration of the sawtooth-shaped exponen- an, at ~4.1 Ga, leaving ~400 Myr of Mars’ earliest tially declining impact fluxes both in the aftermath of evolution effectively unconstrained [1]. However, an planet formation and during the Late Heavy Bom- enduring record of the earlier pre-Noachian conditions bardment [5] suggests that the impact flux during persists in geophysical and mineralogical data. We use much of the pre-Noachian was even lower than indi- geophysical evidence, primarily in the form of the cated above. This bombardment history is consistent preservation of the crustal dichotomy boundary, to- with a late heavy bombardment (LHB) of the inner gether with mineralogical evidence in order to infer the Solar System [6] during which HUIA formed, which prevailing surface conditions during the pre-Noachian. followed the planet formation era impacts during The emerging picture is a pre-Noachian Mars that was which the dichotomy formed. less dynamic than Noachian Mars in terms of impacts, Pre-Noachian Tectonism and Volcanism: The geodynamics, and hydrology. crust within each of the southern highlands and north- Pre-Noachian Impacts: We define the pre- ern lowlands is remarkably uniform in thickness, aside Noachian as the time period bounded by two impacts – from regions in which it has been thickened by volcan- the dichotomy-forming impact and the Hellas-forming ism (e.g., Tharsis, Elysium) or thinned by impacts impact. -
C++ DATE and TIME Rialspo Int.Co M/Cplusplus/Cpp Date Time.Htm Copyrig Ht © Tutorialspoint.Com
C++ DATE AND TIME http://www.tuto rialspo int.co m/cplusplus/cpp_date_time.htm Copyrig ht © tutorialspoint.com The C++ standard library does not provide a proper date type. C++ inherits the structs and functions for date and time manipulation from C. To access date and time related functions and structures, you would need to include <ctime> header file in your C++ prog ram. There are four time-related types: clock_t, time_t, size_t, and tm. The types clock_t, size_t and time_t are capable of representing the system time and date as some sort of integ er. The structure type tm holds the date and time in the form of a C structure having the following elements: struct tm { int tm_sec; // seconds of minutes from 0 to 61 int tm_min; // minutes of hour from 0 to 59 int tm_hour; // hours of day from 0 to 24 int tm_mday; // day of month from 1 to 31 int tm_mon; // month of year from 0 to 11 int tm_year; // year since 1900 int tm_wday; // days since sunday int tm_yday; // days since January 1st int tm_isdst; // hours of daylight savings time } Following are the important functions, which we use while working with date and time in C or C++. All these functions are part of standard C and C++ library and you can check their detail using reference to C++ standard library g iven below. SN Function & Purpose 1 time_t time(time_t *time); This returns the current calendar time of the system in number of seconds elapsed since January 1, 1970. If the system has no time, .1 is returned. -
Ice-Core Dating of the Pleistocene/Holocene
[RADIOCARBON, VOL 28, No. 2A, 1986, P 284-291] ICE-CORE DATING OF THE PLEISTOCENE/HOLOCENE BOUNDARY APPLIED TO A CALIBRATION OF THE 14C TIME SCALE CLAUS U HAMMER, HENRIK B CLAUSEN Geophysical Isotope Laboratory, University of Copenhagen and HENRIK TAUBER National Museum, Copenhagen, Denmark ABSTRACT. Seasonal variations in 180 content, in acidity, and in dust content have been used to count annual layers in the Dye 3 deep ice core back to the Late Glacial. In this way the Pleistocene/Holocene boundary has been absolutely dated to 8770 BC with an estimated error limit of ± 150 years. If compared to the conventional 14C age of the same boundary a 0140 14C value of 4C = 53 ± 13%o is obtained. This value suggests that levels during the Late Glacial were not substantially higher than during the Postglacial. INTRODUCTION Ice-core dating is an independent method of absolute dating based on counting of individual annual layers in large ice sheets. The annual layers are marked by seasonal variations in 180, acid fallout, and dust (micro- particle) content (Hammer et al, 1978; Hammer, 1980). Other parameters also vary seasonally over the annual ice layers, but the large number of sam- ples needed for accurate dating limits the possible parameters to the three mentioned above. If accumulation rates on the central parts of polar ice sheets exceed 0.20m of ice per year, seasonal variations in 180 may be discerned back to ca 8000 BP. In deeper strata, ice layer thinning and diffusion of the isotopes tend to obliterate the seasonal 5 pattern.1 Seasonal variations in acid fallout and dust content can be traced further back in time as they are less affected by diffusion in ice. -
Capricious Suntime
[Physics in daily life] I L.J.F. (Jo) Hermans - Leiden University, e Netherlands - [email protected] - DOI: 10.1051/epn/2011202 Capricious suntime t what time of the day does the sun reach its is that the solar time will gradually deviate from the time highest point, or culmination point, when on our watch. We expect this‘eccentricity effect’ to show a its position is exactly in the South? e ans - sine-like behaviour with a period of a year. A wer to this question is not so trivial. For ere is a second, even more important complication. It is one thing, it depends on our location within our time due to the fact that the rotational axis of the earth is not zone. For Berlin, which is near the Eastern end of the perpendicular to the ecliptic, but is tilted by about 23.5 Central European time zone, it may happen around degrees. is is, aer all, the cause of our seasons. To noon, whereas in Paris it may be close to 1 p.m. (we understand this ‘tilt effect’ we must realise that what mat - ignore the daylight saving ters for the deviation in time time which adds an extra is the variation of the sun’s hour in the summer). horizontal motion against But even for a fixed loca - the stellar background tion, the time at which the during the year. In mid- sun reaches its culmination summer and mid-winter, point varies throughout the when the sun reaches its year in a surprising way. -
Critical Analysis of Article "21 Reasons to Believe the Earth Is Young" by Jeff Miller
1 Critical analysis of article "21 Reasons to Believe the Earth is Young" by Jeff Miller Lorence G. Collins [email protected] Ken Woglemuth [email protected] January 7, 2019 Introduction The article by Dr. Jeff Miller can be accessed at the following link: http://apologeticspress.org/APContent.aspx?category=9&article=5641 and is an article published by Apologetic Press, v. 39, n.1, 2018. The problems start with the Article In Brief in the boxed paragraph, and with the very first sentence. The Bible does not give an age of the Earth of 6,000 to 10,000 years, or even imply − this is added to Scripture by Dr. Miller and other young-Earth creationists. R. C. Sproul was one of evangelicalism's outstanding theologians, and he stated point blank at the Legionier Conference panel discussion that he does not know how old the Earth is, and the Bible does not inform us. When there has been some apparent conflict, either the theologians or the scientists are wrong, because God is the Author of the Bible and His handiwork is in general revelation. In the days of Copernicus and Galileo, the theologians were wrong. Today we do not know of anyone who believes that the Earth is the center of the universe. 2 The last sentence of this "Article In Brief" is boldly false. There is almost no credible evidence from paleontology, geology, astrophysics, or geophysics that refutes deep time. Dr. Miller states: "The age of the Earth, according to naturalists and old- Earth advocates, is 4.5 billion years. -
Two Stages of Late Carboniferous to Triassic Magmatism in the Strandja
Geological Magazine Two stages of Late Carboniferous to Triassic www.cambridge.org/geo magmatism in the Strandja Zone of Bulgaria and Turkey ł ń 1,2 3 1 1 Original Article Anna Sa aci ska , Ianko Gerdjikov , Ashley Gumsley , Krzysztof Szopa , David Chew4, Aleksandra Gawęda1 and Izabela Kocjan2 Cite this article: Sałacińska A, Gerdjikov I, Gumsley A, Szopa K, Chew D, Gawęda A, and 1Institute of Earth Sciences, Faculty of Natural Sciences, University of Silesia in Katowice, Będzińska 60, 41-200 Kocjan I. Two stages of Late Carboniferous to 2 3 Triassic magmatism in the Strandja Zone of Sosnowiec, Poland; Institute of Geological Sciences, Polish Academy of Sciences, Warsaw, Poland; Faculty of ‘ ’ Bulgaria and Turkey. Geological Magazine Geology and Geography, Sofia University St. Kliment Ohridski , 15 Tzar Osvoboditel Blvd., 1504 Sofia, Bulgaria 4 https://doi.org/10.1017/S0016756821000650 and Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland Received: 9 February 2021 Abstract Revised: 3 June 2021 Accepted: 8 June 2021 Although Variscan terranes have been documented from the Balkans to the Caucasus, the southeastern portion of the Variscan Belt is not well understood. The Strandja Zone along Keywords: the border between Bulgaria and Turkey encompasses one such terrane linking the Strandja Zone; Sakar unit; U–Pb zircon dating; Izvorovo Pluton Balkanides and the Pontides. However, the evolution of this terrane, and the Late Carboniferous to Triassic granitoids within it, is poorly resolved. Here we present laser ablation Author for correspondence: – inductively coupled plasma – mass spectrometry (LA-ICP-MS) U–Pb zircon ages, coupled ł ń Anna Sa aci ska, with petrography and geochemistry from the Izvorovo Pluton within the Sakar Unit Email: [email protected] (Strandja Zone).