Carbon 14, long-lived radioactive isotope used in dating organic deposits, is from 1936.
The question of why over the last million years, climatic variation has been driven by the 100,000 year Milankovitch cycle rather than the 41,000 year Milankovitch cycle. A type of lava flow, or the cooled and solidified rock produced by it, characterized by the rough jagged surface of the resulting rock. The end of a glacier; the point at which loss of ice by melting exceeds the supply of ice by the movement of the glacier.
Sandstone formed from sand deposited by the wind, i.e.
A fan-shaped deposit of sediment left where a mountain stream reaches a plain. Radioactive decay involving the emission of an alpha particle. A particle consisting of two protons and two neutrons. Any of an important class of silicate minerals in which the structure involves aluminum-based as well as silicon-based tetrahedra.
The observation that the geological record can be explained in terms of the sort of geological processes that actually happen.
Libby thus reasoned that by measuring carbon 14 levels in the remains of an organism that died long ago, one could estimate the time of its death.
This procedure of radiocarbon dating has been widely adopted and is considered accurate enough for practical use to study remains up to 50,000 years old.
This should not be confused with the usage of the term "anomaly" in the philosophy of science, where it means a measurement or observation which cannot be reconciled with current theory.
A group of silicate minerals in which the Si O units are bonded to form a double chain. The maximum angle from the horizontal that a heap of a given type of sediment can assume without collapsing. An unconformity in which the older strata meet the younger strata at an angle, the older strata being truncated by the erosional surface. In geology, the term "anomaly" means a measurement at some place of some quantity which is different from the average or background value for that quantity. A river which is present before the uplift of the hills through which it flows. A very black, hard, and shiny form of coal produced by metamorphism.