Search results
Results from the WOW.Com Content Network
Homininaeid Era – Period prior to the existence of Homininae Homininid Era – Period prior to the existence of Hominini Prehistory – Period between the appearance of Homo ("humans"; first stone tools c. three million years ago) and the invention of writing systems (for the Ancient Near East : c. five thousand years ago).
As such, this table is not to scale and does not accurately represent the relative time-spans of each geochronologic unit. While the Phanerozoic Eon looks longer than the rest, it merely spans ~539 million years (~12% of Earth's history), whilst the previous three eons [note 2] collectively span ~3,461 million years (~76% of Earth's history ...
The first eon in Earth's history, the Hadean, begins with Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of Earth's crust and Earth itself.
See calendar and list of calendars for other groupings of years. See history , history by period , and periodization for different organizations of historical events. For earlier time periods, see Timeline of the Big Bang , Geologic time scale , Timeline of evolution , and Logarithmic timeline.
Basin Groups Era begins on Earth. c. 4,450 Ma – 100 million years after the Moon formed, the first lunar crust, formed of lunar anorthosite, differentiates from lower magmas. The earliest Earth crust probably forms similarly out of similar material. On Earth the pluvial period starts, in which the Earth's crust cools enough to let oceans form.
The Precambrian includes approximately 90% of geologic time. It extends from 4.6 billion years ago to the beginning of the Cambrian Period (about 539 Ma).It includes the first three of the four eons of Earth's prehistory (the Hadean, Archean, and Proterozoic) and precedes the Phanerozoic eon.
6000 BC: Evidence of habitation at the current site of Aleppo dates to about c. 8,000 years ago, although excavations at Tell Qaramel, 25 kilometres (16 mi) north of the city show the area was inhabited about 13,000 years ago, [124] Carbon-14 dating at Tell Ramad, on the outskirts of Damascus, suggests that the site may have been occupied since ...
500 million years of climate change Ice core data for the past 400,000 years, with the present at right. Note length of glacial cycles averages ~100,000 years. Blue curve is temperature, green curve is CO 2, and red curve is windblown glacial dust (loess). Scale: Millions of years before present, earlier dates approximate.