Pleistocene

The Pleistocene (/ˈplaɪstəˌsiːn, -toʊ-/; symbol PS) is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's recent period of repeated glaciations.

Charles Lyell introduced this term in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today. This distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. He constructed the name "Pleistocene" ("Most New" or "Newest") from the Greek πλεῖστος, pleīstos, "most", and καινός, kainós (latinized as cænus), "new"; this contrasting with the immediately preceding Pleiocene ("More New" or "Newer", from πλείων, pleíōn, "more", and kainós; usual spelling: Pliocene), and the immediately subsequent Holocene ("wholly new" or "entirely new", from ὅλος, hólos, "whole", and kainós) epoch, which extends to the present time.

The Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. The end of the Pleistocene corresponds with the end of the last glacial period. It also corresponds with the end of the Paleolithic age used in archaeology. In the ICS timescale, the Pleistocene is divided into four stages or ages, the Gelasian, Calabrian, Ionian and Tarantian. All of these stages were defined in southern Europe. In addition to this international subdivision, various regional subdivisions are often used.

La Brea Tar Pits

The La Brea Tar Pits are a group of tar pits around which Hancock Park was formed in urban Los Angeles. Natural asphalt (also called asphaltum, bitumen, pitch or tar—brea in Spanish) has seeped up from the ground in this area for tens of thousands of years. The tar is often covered with dust, leaves, or water. Over many centuries, the bones of animals that were trapped in the tar were preserved. The George C. Page Museum is dedicated to researching the tar pits and displaying specimens from the animals that died there. The La Brea Tar Pits is a registered National Natural Landmark.

The modern name is an example of a tautological place name; "the La Brea Tar Pits" literally means "the tar tar pits."

Location and formation

The La Brea Tar Pits and Hancock Park are situated within what was once the Mexican land grant of Rancho La Brea, now part of urban Los Angeles in the Miracle Mile district, adjacent to the Los Angeles County Museum of Art and the Craft and Folk Art Museum.

North America

North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.

North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe.

In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands (most notably the Caribbean) are included.

North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago (the beginning of the Archaic or Meso-Indian period). The Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants. European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French and societies and states commonly reflect Western traditions.

La Brea

La Brea (plural: Las Breas) is Spanish for "the tar" or "the tar pits") and may refer to: