the time of the physical formation and development of the earth (especially prior to human history)
The period of time covering the physical formation and development of Earth, as recorded within the succession of rocks.
A really, really long time... The time that has elapsed since the earth formed some 4.51 (give or take 0.06) billion years ago (Allègre, 1995). For a look at how this vast temporal expanse has been approached by scientists and others, see the UCMP's online exhibit on the history of the geologic timescale.
the succession of eras, periods, and epochs as considered in historical geology. Geologic processes--with the exception of climactic events such as volcanoes and earthquakes--generally occur so slowly as to be imperceptible to humans.
The period of time extending from the formation of the earth to the present. Geologic Time Scale An arbitrary chronologic sequence of geologic events, used as a measure of the age of any part of geologic time, usually presented in the form of a chart showing the names of the various rock-stratigraphic, time-stratigraphic, or geologic-time units.
Mammals arose in the Mesozoic Era, which began some 230 million years ago. The following Cenozoic Era, the “Age of Mammals” was the time of evolution and radiation of major modern mammalian groups. The Cenozoic is divided into two periods, Tertiary (beginning about 63 million years ago and continuing until about two million years ago) and Quaternary (approximately two million years ago to present). Subdivisions of the Tertiary (termed epochs) are (oldest to youngest): Paleocene; Eocene, which began about 58 mya, Oligocene, which began about 36 mya; Miocene, which began about 25 mya; and Pliocene, which began less than 10 mya. The Quaternary has only two epochs, Pleistocene (1.8 mya to 10,000 years ago) and Recent (or Holocene-about 10,000 years ago until present.
all time since the Earth was formed and continuing to the present.
The vast stretch of time over which Earth's geologic development has occurred. This span (about 4.6 billion years) dwarfs the history of human existence, which is only about two million years. Much smaller still is the span of human civilization, only about 5,500 years.
The time extending from the end of the formative period of the Earth to the beginning of human history.
The time scale used to describe events in the history of Earth.
the time of existence of the earth before the ages of human history, as studied by historical geology. [AHDOS
Time as considered in terms of the history of the earth. It is divided into geologic eras, periods, and epochs. Depending on the part of the geologic time scale, increments are as long as tens of millions of years or as short as hundreds of years. In general, geologic time is more finely divided closer to the present.