Relative age dating inclusions dating site for european single
This is a simplified cartoon of the quarry at Redgranite, Wisconsin (see photos above) with relative timing of event interpretations (numbers 1-7, with #1 being the oldest event).
There is a vertical sheet-like mafic intrusion (see photo above) cuts the granite; because it cuts the granite, it post dates the granite and because the granite baked layers 1-3, the mafic intrusion (#5) post dates layers 1-3 and the granite.
Different species of ammonites lived at different times within the Mesozoic, so identifying a fossil species can help narrow down when a rock was formed.
Correlation can involve matching an undated rock with a dated one at another location.
For example, microscopic dinoflagellates have been studied and dated in great detail around the world.
Some fossils, called index fossils, are particularly useful in correlating rocks.
For a fossil to be a good index fossil, it needs to have lived during one specific time period, be easy to identify and have been abundant and found in many places. If you find ammonites in a rock in the South Island and also in a rock in the North Island, you can say that both rocks are Mesozoic.
Unformatted text preview: Page 2 Telling Reiative Time Use the laws of superposition, inclusions and cross-cutting relationships to determine the relative ages of the foiiowing cross-sections. Youngest __A__ D _..— “Em“ 0mm _i..__._ smﬂbr'apﬁie mania: WMEM SW SC1D UNIT 6 Earth Forces Reiative Dating WS H Youngest Oldest .
L Outline the sequence of events in the cross sections below by numbering each rock unit or event in the order in which it occurred or was deposited.Throughout the history of life, different organisms have appeared, flourished and become extinct.