Radiometric dating system

25 Jan

Fundamental to stratigraphy are a set of simple principles, based on elementary geometry, empirical observation of the way these rocks are deposited today, and gravity.

It can't float in mid-air, particularly if the material involved is sand, mud, or molten rock.

The principle of superposition therefore has a clear implication for the age of a vertical succession of strata.

This document is partly based on a prior posting composed in reply to Ted Holden.

My thanks to both him and other critics for motivating me.

The simplest situation for a geologist is a "layer cake" succession of sedimentary or extrusive igneous rock units arranged in nearly horizontal layers.In such a situation, the "principle of superposition" is easily applied, and the strata towards the bottom are older, those towards the top are younger.There are situations where it potentially fails -- for example, in cave deposits.In this situation, the cave contents are younger than both the bedrock below the cave and the suspended roof above.They are the "initial working hypotheses" to be tested further by data.