Varve series: A number of varve records that have been matched from a relatively constrained area and together make a longer and more accurate sequence than a single varve record.Numbering of a series often starts at 1 at the bottom (oldest varve) and implies a higher level of accuracy than can be achieved with a single varve record.When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element.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.Varve record: A measured string of varves from a single exposure or drill core.
In archaeology, absolute dating is usually based on the physical, chemical, and life properties of the materials of artifacts, buildings, or other items that have been modified by humans and by historical associations with materials with known dates (coins and written history).
Throughout this web site the terms varve record, varve series, and varve chronology are used to denote varve sequences of different hierarchical status.
The term “varve sequence” is used as a generic term to refer to any succession of varves regardless of whether they are single outcrop records or represent larger, more regional correlations involving many varve records.
In historical geology, the primary methods of absolute dating involve using the radioactive decay of elements trapped in rocks or minerals, including isotope systems from very young (radiocarbon dating with Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes.
Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age.