The Paleogene Period is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 Ma to the beginning of the Neogene Period 23.03 Ma. It is the first period of the Cenozoic Era, the tenth period of the Phanerozoic and is divided into the Paleocene, Eocene, and Oligocene epochs. The earlier term Tertiary Period was used to define the time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. Paleogene is often abbreviated "Pg", although the United States Geological Survey uses the abbreviation "Pe" for the Paleogene on the Survey's geologic maps.
Laurasia was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around 335 to 175 million years ago (Mya), the other being Gondwana. It separated from Gondwana 215 to 175 Mya during the breakup of Pangaea, drifting farther north after the split and finally broke apart with the opening of the North Atlantic Ocean c. 56 Mya. The name is a portmanteau of Laurentia and Eurasia.
Panthalassa, also known as the Panthalassic Ocean or Panthalassan Ocean, was the vast superocean that encompassed planet Earth and surrounded the supercontinent Pangaea, the latest in a series of supercontinents in the history of Earth. During the Paleozoic–Mesozoic transition, the ocean occupied almost 70% of Earth's surface, with the supercontinent Pangaea taking up less than half. The original, ancient ocean floor has now completely disappeared because of the continuous subduction along the continental margins on its circumference. Panthalassa is also referred to as the Paleo-Pacific or Proto-Pacific because the Pacific Ocean is a direct continuation of Panthalassa.
Columbia, also known as Nuna or Hudsonland, is a hypothetical ancient supercontinent. It was first proposed by John J.W. Rogers and M. Santosh in 2002 and is thought to have existed approximately 2,500 to 1,500 million years ago (Ma), in the Paleoproterozoic era. The assembly of the supercontinent was likely completed during global-scale collisional events from 2,100 to 1,800 Ma.
The Indian plate is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian plate broke away from the other fragments of Gondwana 100 million years ago and began moving north, carrying Insular India with it. It was once fused with the adjacent Australian plate to form a single Indo-Australian plate; recent studies suggest that India and Australia have been separate plates for at least 3 million years. The Indian plate includes most of modern South Asia and a portion of the basin under the Indian Ocean, including parts of South China, western Indonesia, and extending up to but not including Ladakh, Kohistan, and Balochistan in Pakistan.
The Somali plate is a minor tectonic plate which straddles the Equator in the Eastern Hemisphere. It is currently in the process of separating from the African plate along the East African Rift Valley. It is approximately centered on the island of Madagascar and includes about half of the east coast of Africa, from the Gulf of Aden in the north through the East African Rift Valley. The southern boundary with the Nubian–African plate is a diffuse plate boundary consisting of the Lwandle plate.
The Pan-African orogeny was a series of major Neoproterozoic orogenic events which related to the formation of the supercontinents Gondwana and Pannotia about 600 million years ago. This orogeny is also known as the Pan-Gondwanan or Saldanian Orogeny. The Pan-African orogeny and the Grenville orogeny are the largest known systems of orogenies on Earth. The sum of the continental crust formed in the Pan-African orogeny and the Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust.
Cimmeria was an ancient continent, or, rather, a string of microcontinents or terranes, that rifted from Gondwana in the Southern Hemisphere and was accreted to Eurasia in the Northern Hemisphere. It consisted of parts of present-day Turkey, Iran, Afghanistan, Pakistan, Tibet, China, Myanmar, Thailand, and Malaysia. Cimmeria rifted from the Gondwanan shores of the Paleo-Tethys Ocean during the Early Permian and as the Neo-Tethys Ocean opened behind it, during the Permian, the Paleo-Tethys closed in front of it. Because the different chunks of Cimmeria drifted northward at different rates, a Meso-Tethys Ocean formed between the different fragments during the Cisuralian. Cimmeria rifted off Gondwana from east to west, from Australia to the eastern Mediterranean. It stretched across several latitudes and spanned a wide range of climatic zones.
This is a brief summary of the geology of Indonesia. Indonesia is located between two major tectonic plates namely, the Australian Plate and the newly-separated Sunda Plate.
Continental crustal fragments, partly synonymous with microcontinents, are pieces of continents that have broken off from main continental masses to form distinct islands that are often several hundred kilometers from their place of origin.
Gondwana was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia, Zealandia, Arabia, and the Indian Subcontinent.
Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million years ago, and began to break apart about 200 million years ago, at the end of the Triassic and beginning of the Jurassic. Pangaea was C-shaped, with the bulk of its mass stretching between Earth's northern and southern polar regions and surrounded by the superocean Panthalassa and the Paleo-Tethys and subsequent Tethys Oceans. Pangaea is the most recent supercontinent to have existed and the first to be reconstructed by geologists.
This is a list of articles related to plate tectonics and tectonic plates.
The Madagascar plate or Madagascar block is a tectonic plate holding the island of Madagascar. It was once attached to the Gondwana supercontinent and later the Indo-Australian plate.
The Shan–Thai or Sibumasu Terrane is a mass of continental crust extending from Tibet into Southeast Asia sharing a similar geological history. The Shan–Thai Terrane rifted from Australia in the Permian and collided with the Indochina terrane in the Triassic. It extends from Malaysia, through peninsular Thailand, Myanmar, West Yunnan, to Lhasa.
The Lhasa terrane is a terrane, or fragment of crustal material, sutured to the Eurasian Plate during the Cretaceous that forms present-day southern Tibet. It takes its name from the city of Lhasa in the Tibet Autonomous Region, China. The northern part may have originated in the East African Orogeny, while the southern part appears to have once been part of Australia. The two parts joined, were later attached to Asia, and then were impacted by the collision of the Indian Plate that formed the Himalayas.
The base of rocks that underlie Borneo, an island in Southeast Asia, was formed by the arc-continent collisions, continent–continent collisions and subduction–accretion due to convergence between the Asian, India–Australia, and Philippine Sea-Pacific plates over the last 400 million years. The active geological processes of Borneo are mild as all of the volcanoes are extinct. The geological forces shaping SE Asia today are from three plate boundaries: the collisional zone in Sulawesi southeast of Borneo, the Java-Sumatra subduction boundary and the India-Eurasia continental collision.
The paleogeography of the India–Asia collision system is the reconstructed geological and geomorphological evolution within the collision zone of the Himalayan orogenic belt. The continental collision between the Indian Plate and Eurasian Plate is one of the world's most renowned and most studied convergent systems. However, many mechanisms remain controversial. Some of the highly debated issues include the onset timing of continental collision, the time at which the Tibetan plateau reached its present elevation and how tectonic processes interacted with other geological mechanisms. These mechanisms are crucial for the understanding of Mesozoic and Cenozoic tectonic evolution, paleoclimate and paleontology, such as the interaction between the Himalayas orogenic growth and the Asian monsoon system, as well as the dispersal and speciation of fauna. Various hypotheses have been put forward to explain how the paleogeography of the collision system could have developed. Important ideas include the synchronous collision hypothesis, the Lhasa-plano hypothesis and the southward draining of major river systems.
Greater Adria was a paleomicrocontinent that existed from 240 to 140 million years ago. It is named after Adria, a geologic region found in Italy, where evidence of the microcontinental fragment was first observed. Greater Adria's size can be compared to that of modern day Greenland.
