By comparing overall formations, geologic structures and local strata, calibrated by those layers which are widespread, a nearly complete geologic record has been constructed since the 17th century.
Lithostratigraphic units are bodies of rocks, bedded or unbedded, that are defined and characterized on the basis of their lithologic properties and their stratigraphic relations. The element of stratigraphy that deals with the description and nomenclature of the rocks of the Earth based on their lithology and their stratigraphic relations. Lithostratigraphic units are defined and recognized by observable physical features and not by their inferred age, the time span they represent, inferred geologic history, or manner of formation.
Exploring this series of exhibits will take you on a journey through the history of the Earth, with stops at particular points in time to examine the fossil record and stratigraphy.
The Geology Wing is organized according to the geologic time scale.
For each dating or chronological method there is a link in the box at right to take you to that section of this page.
There, you will find a brief description of the method, plus links to take you to other webpages with more extensive information.
Archaeological geology as a science had to precede the proposal of evolution, as an understanding of the immense age of the earth is necessary to understand evolution.
Cuvier established amongst the scientific community the fact of extinction.
However using broadly occurring deposited layers trapped within differently located rock columns, geologists have pieced together a system of units covering most of the geologic time scale using the law of superposition, for where tectonic forces have uplifted one ridge newly subject to erosion and weathering in folding and faulting the strata, they have also created a nearby trough or structural basin region that lies at a relative lower elevation that can accumulate additional deposits.According to the law of superposition, sedimentary and volcanic rock layers are deposited on top of each other.They harden over time to become a solidified (competent) rock column, that may be intruded by igneous rocks and disrupted by tectonic events.Evolution & Ecology " (see its HOME PAGE .) The result is that some areas, such as the glossary are shared.Widgets Human evolution from an ancestral primate species is not a vague hypothesis, but a historical fact.