https://padlet.com/310047/xkk5huhc6tq5 Geologic Time Scale en-us 2018-01-16 22:42:53 UTC 2026-01-12 13:47:09 UTC hello@padlet.com 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911057 In geology and related fields, a stratum (plural: strata) is a layer of sedimentary rock or soil, or igneous rock where formed at the earth's surface, with internally consistent characteristics that distinguish it from other layers.]]> 2018-01-16 22:45:15 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911057 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911372 the time taken for the radioactivity of a specified isotope to fall to half its original value.]]> 2018-01-16 22:47:14 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911372 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911520 the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.]]> 2018-01-16 22:48:18 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911520 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911695 Earth formed around 4.54 billion years ago by accretion from the solar nebula. ... The Hadean eon represents time before the reliable (fossil) record of life beginning on Earth; it began with the formation of the planet and ended at 4.0 billion years ago as defined by international convention.

]]> 2018-01-16 22:49:42 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911695 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911845 an idealized cycle of processes undergone by rocks in the earth's crust, involving igneous intrusion, uplift, erosion, transportation, deposition as sedimentary rock, metamorphism, remelting, and further igneous intrusion.]]> 2018-01-16 22:51:16 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911845 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221911980 a method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample.]]> 2018-01-16 22:52:31 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221911980 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221912129 another term for carbon dating.]]> 2018-01-16 22:54:03 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221912129 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221912334 radioactive decay. (rā'dē-ō-āk'tĭv) The spontaneous transformation of an unstable atomic nucleus into a lighter one, in which radiation is released in the form of alpha particles, beta particles, gamma rays, and other particles.]]> 2018-01-16 22:56:03 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221912334 310047 https://padlet.com/310047/xkk5huhc6tq5/wish/221912660 The age of the Earth is approximately 4.54 ± 0.05 billion years (4.54 × 10⁹ years ± 1%). This dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.]]> 2018-01-16 22:58:58 UTC https://padlet.com/310047/xkk5huhc6tq5/wish/221912660