Hominoid species

Relative Dating

Absolute Dating

Law of superposition Looking at layers in the ground – lower layers are older Any Time

Stratigraphic Correlation The process of matching up strata from several sites through the analysis of chemical, physical, and other properties Any Time

Biostratigraphic (faunal) dating

Uses associations of fossils in strata to determine each layer’s approximate age – draws on the 1st appearance of an

organism in the fossil record, its evolutionary development, and extinction

Any Time

Fluorine Dating Dating method that compares the accumulation of fluorine in animal and human bones <100,000yBP

Index Fossil Fossils that are from specified time ranges, are found in multiple locations, and can be used to determine age of

associated strata Any Time

Cultural Dating Use of material objects to provide date information 2.5 mya

Dendrochronology Use of tree ring # (1 ring = 1 year) to provide a date <12,000yBP

Radiocarbon Dating Looks at the ratio of Carbon-14 to Carbon-12 to provide a date 50,000yBP-AD

1950

Radiopotassium Dating Looks at the ratio of Potassium-40 to Argon-40, since

potassium decays to argon, to provide a date. Only works for Igneous rock

>200,000yBP

Argon-Argon Dating Looks at ratio of Argon-39 to Argon-40 5 millionyBP-100,000yBP

Fission Track Dating Based on the radioactive decay of Uranium-238, which leaves lines in rock crystal. More lines = older <3mya

Amino Acid Dating Used only with organic material and looks at the ratio of L- isomers to D-isomers (racemization), highly dependent on

environmental temperature <3mya

Paleomagnetic Dating Dating based on the record of earth’s poles reverse, which

leaves traces through the orientation of metals in sedimentary rock

<5mya

Electron Spin Resonance Dating

Bones and teeth absorb uranium once buried, this method measures the concentration of that uranium – more uranium =

older specimen 1mya-3kya

Thermoluminescence Dating

Heat something up, the amount of light released reveals the amount of time since the material was first heated. More light

= more time elapsed since last heated <800,000yBP