https://padlet.com/3047811/ii8sxg7v5a5t en-us 2018-01-23 17:30:19 UTC 2025-10-19 15:43:51 UTC hello@padlet.com 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223900188 The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time. ]]> 2018-01-23 17:31:29 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223900188 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223901060 A stratum 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.]]> 2018-01-23 17:32:48 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223901060 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223901712 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.]]> 2018-01-23 17:33:48 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223901712 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902358 The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.]]> 2018-01-23 17:34:48 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902358 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902564 The time taken for the radioactivity of a specified isotope to fall to half its original value.]]> 2018-01-23 17:35:11 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902564 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902960 A method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample.]]> 2018-01-23 17:35:49 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223902960 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223904813 The determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.]]> 2018-01-23 17:38:38 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223904813 3047811 https://padlet.com/3047811/ii8sxg7v5a5t/wish/223904975 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.]]> 2018-01-23 17:38:56 UTC https://padlet.com/3047811/ii8sxg7v5a5t/wish/223904975