Holocene
This epoch is part of theQuaternary period. |
Pleistocene |
Holocene |
The Holocene Epoch is a geologic period that extends from the present back about 10,000 radiocarbon years. The beginning of the Holocene corresponds to the end of the Younger Dryas cold period, the final part of Pleistocene epoch. The end of the Younger Dryas has been dated to about 9600 BC (11550 calendar years BP).
The Holocene starts late in the retreat of the Pleistocene glaciers. The Holocene is the second and last epoch of the Quaternary period. The name is derived from the Greek holos (entire(ly)) and ceno (new). It has also been called the "Alluvium Epoch".
Paleontologists have defined no faunal stages for the Pleistocene or Holocene.
Continental motions are negligible over a span of only 10,000 years -- less than a kilometer. However, world sea levels rose about 35 meters (110 feet) in the early part of the Holocene due to ice melt. In addition, many areas above about 40 degrees latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 meters over the late Pleistocene and Holocene. The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea. Holocene marine fossils are known from Vermont, Quebec, Ontario, and Michigan. Other than higher latitude temporary marine incursions associated with glacial depression, Holocene fossils are found primarily in lakebed, floodplain, and cave deposits. Holocene marine deposits along coastlines are rare because the rise in sea levels during the period exceeds any likely upthrusting of non-glacial origin.
Although geographic shifts in the Holocene were minor, climatic shifts were very large. Habitable zones expanded Northwards. Large mid-latitude area such as the Sahara that were previously productive became deserts. The epoch started with large lakes in many areas that are now quite arid. It is possible that the Holocene warming is merely another interglacial period and does not represent a permanent end to the Pleistocene glaciation. Animal and plant life did not evolve much during the Holocene, but there were major shifts in the distributions of plants and animals. A number of large animals including mammoths and mastodons, saber tooth cats, and giant sloth disappeared in the late Pleistocene and early .,Holocene -- especially in North America where common animals that survived elsewhere including horses and camels became extinct. Throughout the world, cooler climate ecosystems that were previously regional have been isolated in higher altitude ecological "islands."
The beginning of the Holocene corresponds with the beginning of the Mesolithic age used in archaeology.
See also: Holocene extinction event, Geologic timescale, Centuries
