Relative age dating geologic cross sections datingpro 2016 nulled
Geologists establish the age of rocks in two ways: numerical dating and relative dating.Numerical dating determines the actual ages of rocks through the study of radioactive decay.Geologic time covers the whole sweep of earth's history, from how and when the earth first formed, to everything that has happened on, in, and to the planet since then, right up to now.Geologists analyze geologic time in two different ways: in terms of relative geologic age, and in terms of absolute (or numeric) geologic age.Absolute geologic age refers to how long ago a geologic event occurred or a rock formed, in numeric terms, such as 65.5 million years ago.Some rocks and minerals can have their absolute age directly measured by analyzing the ratios of certain radioactive and non-radioactive isotopes they contain.Explanations: A – folded rock strata cut by a thrust fault; B – large intrusion (cutting through A); C – erosional angular unconformity (cutting off A & B) on which rock strata were deposited; D – volcanic dike (cutting through A, B & C); E – even younger rock strata (overlying C & D); F – normal fault (cutting through A, B, C & possibly E).
Cross-cutting relations can be used to determine the relative ages of rock strata and other geological structures.
The combination of these two types of geologic ages makes a complete record of earth's geologic history in terms of the order of events and in terms of how many years ago each event occurred.
Relative geologic age refers to the order in which geologic events occurred.
Cross-cutting relationships may be seen cartographically, megascopically, and microscopically.
In other words, these relationships have various scales.