ANSWER: Absolute dating is used by geologists to determine the actual age of a material.
It can be achieved through the use of historical records and through the analysis of biological and geological patterns.
This means that if we didn't have any other way of doing absolute dating, we would as a first approximation take the age of basalt on a spreading sea floor to be the distance from the rift divided by the rate of spreading.
Now if we estimate the age of the sea floor like that, then we get a good agreement with the dates produced by radiometric methods.
A varve is a sedimentary bed, or sequence of beds, deposited in a body of still water within a year’s time.
Counting and correlation of varves have been used to measure the age of Pleistocene glacial deposits.
Although development of radiometric methods led to the first breakthroughs in establishing an absolute time scale, other absolute methods have limited applications.
Chief among these are dendochronology, varve analysis, hydration dating, and TL dating.Dendochronology This method of dating is based on the number, width, and density of annual growth rings of long-lived trees.A master tree-ring index has been constructed in the southwestern United States for the Douglas fir and bristlecone pine.This is different to relative dating, which only puts geological events in time Most absolute dates for rocks are obtained with radiometric methods.These use radioactive minerals in rocks as geological clocks.Science, since it concerns just one universe with one set of laws, constitutes a seamless whole; we cannot unpick the single thread of absolute dating without the whole thing beginning to unravel.