دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a geological time from 500 million to 570 million years ago. Often signals the earliest hydrocarbon productive rocks.

n: the long periods of time dealt with and identified by geology. Geologic time is divided into eras (usually Cenozoic, Mesozoic, Paleozoic, and Precambrian),which are subdivided into periods and epochs. When the age of a type of rock is determined, it is assigned a place in the scale and thereafter referred to as, for example, Mesozoic rock of the Triassic period.

the geologic time from 570 million years ago to be beginning of the earth. Most rocks in this period have no hydrocarbons.

n: a span of 4 billion years from the earths beginning until 600 million years ago, during which the earth was devoid of all but the most primitive life forms.