Impacts from Space and Mass Extinction Events.docx

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University of British Columbia
Earth and Ocean Sciences
EOSC 114
Stuart Sutherland

General Extinction Biostratigraphy: analysis of the earth’s stratified layers to uncover evidence based from fossils  Principle of superposition: rock layer at the bottom of the pile will be the oldest; top layer = youngest  Principle of faunal succession: strata of like age can be recognized by fossils they contain even if they are separated by a large distance o (faunal means animals and plants of a particular region) Subdivisions of Time:  Eons  Eras  Peroids Phanerozoic  emergence of creatures with hard parts Base of periods defined on emergence or radiation of new species  Base of Mesozoic and Cenozoic  emergence of new species following mass extinction Mass Extinction:  30% of earth’s species gone  broad range of ecologies  within 1 mill years Biological cause of mass extinction  Competition  Excessive predation  Pathogens Earth based cause of mass extinction  Change in continent configuration o Climate o Ocean cyclinity o Sea level  weather patterns o Greater the landmass = lower the diversity  Changes in the atmosphere o Greenhouse warming and shit Extraterrestrial impacts cause of mass extinction Permo-Triassic Extinction 95-98% of all species extinct  continental config: drop in biodiversity  sea floor spreading slowed down: sea level dropped  fucked over shallow habitats  climate got drier and more drought because of large landmass  Siberian traps: lot of volcanic activity  acid rain  Meteor strikes. anoxia a lack of oxygen atmosphere layer of gases surrounding the lithosphere biodiversity the number of different species biosphere global sum of all ecosystems biostratigraphy correlation of rocks using fossils Cambrian oldest period of the Phanerozoic / Paleozoic Cenozoic the most recent grouping of geological periods in the Phanerozoic correlation matching geological sections that might be separated by large distances Cretaceous youngest period of the Mesozoic Terms Cross-Cutting Relationships Page 15 of 42 method of deduction of relative age of geological sections Cuvier, George established concept of extinction Deep Time understanding the extreme age of Earth Devonian geological period in the Paleozoic Earth System Science understanding Earth as an interaction of many systems (spheres) ecosystem a collection of living organisms that interacts with the Earth System evolved/evolution theory to explain biodiversity and emergence of new species extinct/extinction death of every member of a species Faunal Succession change in fossil species over time flood basalt basalt lava produced by large scale volcanic activity foraminifera microfossils that commonly secrete a calcium carbonate shell fossil range length of geological time a species existed on Earth Ga glaciation/glacial period cold climatic periods marked by the advance of glaciers Gondwana southern part of Pangea greenhouse gas gases in the atmosphere that contribute to global warming Hutton, James Scottish Geologist; used cross cutting relationships in Earth age studies hydrosphere all Earth's liquid water lithosphere outer layers of the Earth including the crust and uppermost mantle Ma Mesozoic grouping of geological periods: oldest Triassic, youngest Cretaceous microfossils all fossils just at the limit or smaller than can be seen by the naked eye Ordovician a period in the Paleozoic Original Horizontality a stratigraphic principle Paleogene oldest geological period of the Cenozoic Paleozoic a grouping of geological periods; the oldest grouping of the Phanerozoic Pangea large landmass that existed during the Permian periods geological time divisions Permian a geological period; youngest period in the Paleozoic Phanerozoic Giga annum: billions of years ago Mega annum: millions of years ago grouping of all geological periods after the Precambrian Page 16 of 42 Precambrian grouping of all geological periods older than the Cambrian/Phanerozoic radiation the emergence of new species following a mass extinction event Smith, William English engineer who developed the concept of faunal succession Steno, Nicholas Danish anatomist who developed the principles of stratigraphy strata stratigraphy/stratigraphic study of the manner in which strata are laid down supercontinent a landmass comprising of more than one continental core Superposition stratigraphic principle which says “What is on top is youngest” Triassic youngest geological period of the Mesozoic Unconformity an erosion surface separating two rock masses of different ages Ussher, James Archbishop of Armagh who believed Earth was created in 4004 BC Cretaceous – Paleogenic extinction 12/13/2012 1:07:00 AM Cretaceous – Paleogenic (K/Pg) Extinction event dinosaurs died what does k/pg mean Alvarez thought the strong presence of iridium (especially since it is very rare to be on earths surface) meant that a meteor hit the earth – over 10 km in diameter  Fern Spores vs Pollen o Fern are primary species after a fire  lot more fern spores vs pollen which means there must have been a lot of forest fires  Tektites o Produced during an impact event o Natural glass  melted rock ejected forming special shape  Shocked Quartz o Fractures in quartz near k/pg boundary thought to be produced during a high-energy impact o Fragments called shocked quartz  Tsunami Deposits o Leave characteristic sedimentary deposits  Chicxulub Impact Crater o They found the crater in mexico o Analogous to something the size of mount Everest hitting the planet Consequences of Chicxulub  Initial o Shit got vaporizzzzzed o Started a lot of massive forest fires cuz of intense heat  as suggested by fern and pollen data o Massive tsunami cuz it happened partly in the ocean  Long Term Effect: o Global temp change  Dust in air causes “Cold House effect” (lack of sunlight to warm planet)  After dust settles; Water vapour remains in atmosphere causes “Greenhouse effect” (trap heat inside atmosphere)  After it rains; greenhouse gasses continue to raise temp (like co2 from limestone that got vaped during impact) o Acid Rain  O2 and n2  nitric acid  Rocks called evaporates also vaped in blast  “evaps” form when body of water dries up and leaves the mineral and salt behind.  When vaped it releases sulfur gas  sulfuric acid  Nitric and sulfuric acid are weak, but affected the soil and surface ocean which fucked over the base of food chain. Other reasons for K/Pg Extinction  Fragmentation of Pangaea caused changes in oceanic circulation and climate  Increase in volcanic activity  more gases; mess around with earth’s climate Generalists: creatures that
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