Geologic Time
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| 1318828742 | Catastrophism | Earth's landscape primarily developed by great catastrophes; mid-1600's concept (wrong: geologic processes take lots of time) | 1 | |
| 1318828743 | Uniformitarianism | "The present is the key to the past"; the physical, chemical and biological laws that operate today have also operated in the geologic past; (James Hutton, late 1700's) | 2 | |
| 1318828744 | Charles Lyell | Principles of Geology (1830-1872); presented Huton's ideas | 3 | |
| 1318828745 | Law of Superposition | each bed of rocks is older than the one above it( i.e.: rocks are younger on the top, and older on the bottom) |  | 4 |
| 1318828746 | Principle of Original Horizontality | layers of sediment are deposited in a horizontal position | 5 | |
| 1318828747 | Principle of Cross;Cutting Relationships | a cross-cutting fault or intrusion is younger than the rocks |  | 6 |
| 1318828748 | Principle of Inclusions | the rock mass which contains inclusions (rock fragments) is the younger of the two |  | 7 |
| 1318891223 | Unconformities | represents a long period of time during which sediment deposition ceased... and erosion removed previously formed rocks,... then deposition resumed *A break in the time-record | 8 | |
| 1318891224 | Angular Unconformity | tilted rocks are overlain by younger, flat-lying rocks |  | 9 |
| 1318891225 | Disconformity | strate, on either side of erosionsurface, are parallel - deposition... erosion & mountain building.. deposition continues |  | 10 |
| 1318891226 | Nonconformity | sedimentary rocks overlying plutonic or metamorphic rocks; *there must have been a time of uplift and erosion of overlying rocks before deposition of sedimentary rocks |  | 11 |
| 1318891227 | Correlation of Rock Layers | matching rocks of similar age -or- matching rocks that are similar, but a distance away from each other | 12 | |
| 1318891228 | Fossils | Indirect & Direct evidence of Past Life | 13 | |
| 1318891229 | Molds & Casts | impression/mold filled and cast with silt or minerals |  | 14 |
| 1318891230 | Replacement | solid materials of plant or animal are removed and replaced with minerals |  | 15 |
| 1318891231 | Petrified | pores and cavities of plant or animal are filled with minerals |  | 16 |
| 1318891232 | Carbonization | fluids of plant or animal are squeezed out by pressure, leaving only carbon film behind |  | 17 |
| 1318891233 | Tracks | animal footprints left in soft sediment |  | 18 |
| 1318891234 | Burrows | tubes (worm tubes) in sediment; preserve well |  | 19 |
| 1318891235 | Coprolites | fossil dung |  | 20 |
| 1318891236 | Gastroliths | stomach stones in extinct reptiles |  | 21 |
| 1318891237 | conditions favoring preservation | -possession of hard body parts -rapid burial (otherwise they'll oxidize/rot) | 22 | |
| 1318891238 | Index Fossil | geographically widespread via the oceans/other waters (accurate indicator of climate change); limited to a short span of geologic time, via the oceans/other waters | 23 | |
| 1318891239 | Atomic Number | number of Protons: an element always has the same atomic number | 24 | |
| 1318891240 | Atomic Mass | number of protons and neutrons | 25 | |
| 1318891241 | Isotope | different number of neutrons | 26 | |
| 1318891242 | Alpha particle | 2 protons and 2 neutrons emitted | 27 | |
| 1318891243 | Beta particle | electron emitted from nucleus; a neutron is a combination of a proton and an electron | 28 | |
| 1318891244 | Electron captured by nucleus | electron comines with a proton to produce a neutron, making it one less proton, so atomic number decreases parent isotope; the unstable, radioactive isotope daughter product is result from radioactive decay | 29 | |
| 1318891245 | Radometric Dating | rates of radioactive decay are predictable and precisely measured; | 30 | |
| 1318891246 | Half-Life | the time required for one half of nucleii in a sample to radioactively decay ; when amount of parent isotope equals amount of daughter product, one "half-life" has occured * if the half-life of an isotope is known... and amounts of parent-to-daughter atoms can be measured... then the ABSOLUTE AGE (in years) can be measured*** | 31 | |
| 1318891247 | Carbon 14 half-life | 5,730 years; used in Holocene (11ky long) geology *C-14 is taken into LIVING ORGANISMS, so when an organism dies, radioactive decay process begins (and dating can be done from that moment) | 32 | |
| 1318891248 | Carbon-14 Cycle | 1) cosmic rays shatter nucleii of atmospheric gas atoms-->release neutrons 2) nitrogen gas (N-14) absorbs neutron--> becomes N-15 3) N-14 emits proton (# of protons has gone from 7 down to 6, so it's now carbon) 4) release of beta particle (electron)--> Carbon-14 Repeat | 33 | |
| 1318891249 | EONS | Phanerozoic Proterozoic | 34 | |
| 1318891250 | ERAS | (Mid Life): Cenozoic Mesozoic Paleozoic (ended 245 mya) | 35 | |
| 1318891251 | PERIODS | Young Life: Quaternary (1.65mya) Tertiary (65mya) Mid Life: Cretaceous Jurassic Triassic (248 mya) Old Life: Permian Pennsylvanian Mississippian Devonian Silurian Ordovician Cambrian (542 mya) | 36 | |
| 1318891252 | EPOCHS | Holocene (11kya/present): Youngest Epoch* Pleistocene (1.8-1.65mya) Pliocene (2-5.5mya) Miocene (5.5-23mya) Oligocene Eocene Paleocene | 37 | |
| 1318891253 | Epoch | subdivision of the geologic timescale based on rock-layering. | 38 | |
| 1349986556 | Erosion Under the Sea | Because, once exposed to air, sea level dropped | 39 | |
| 1349986558 | Global Cooling | Arctic freezes, and the oceans lower | 40 | |
| 1349986560 | Global Warming | Arctic thaws, and the oceans rise | 41 |
