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101-708: Activity began in the Miocene and continued into the Holocene ; a mural found in the archeological site of Çatalhöyük has been controversially interpreted as showing a volcanic eruption or even a primitive map . It was the second mountain from the south in the Byzantine beacon system used to warn the Byzantine capital of Constantinople of incursions during the Arab–Byzantine wars . The modern name of Mount Hasan

202-511: A cinder cone that was active 2000 years ago, and there is evidence that fumarolic and seismic activity has increased during the 2020s. Reportedly, there are frequent explosions within the volcano. Future activity at Hasan could impact neighbouring villages, and larger eruptions might disrupt air traffic and tourism in Cappadocia. As of 2022 the volcano is not monitored. A mural discovered in Çatalhöyük has been interpreted as showing

303-441: A lava flow around the cone's base. When the eruption ends, a symmetrical cone of cinders sits at the center of a surrounding pad of lava. If the crater is fully breached, the remaining walls form an amphitheater or horseshoe shape around the vent. Basaltic cinder cones are the most characteristic type of volcano associated with intraplate volcanism . They are particularly common in association with alkaline magmatism , in which

404-443: A volcanic vent . The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as either cinders, clinkers, or scoria around the vent to form a cone that often is symmetrical; with slopes between 30 and 40°; and a nearly circular ground plan. Most cinder cones have

505-486: A bowl-shaped crater at the summit. Cinder cones range in size from tens to hundreds of meters tall. They are composed of loose pyroclastic material ( cinder or scoria ), which distinguishes them from spatter cones , which are composed of agglomerated volcanic bombs . The pyroclastic material making up a cinder cone is usually basaltic to andesitic in composition. It is often glassy and contains numerous gas bubbles "frozen" into place as magma exploded into

606-542: A broader aridification trend. The EMCI ended 18 million years ago, giving way to the Middle Miocene Warm Interval (MMWI), the warmest part of which was the MMCO that began 16 million years ago. As the world transitioned into the MMCO, carbon dioxide concentrations varied between 300 and 500 ppm. Global annual mean surface temperature during the MMCO was about 18.4 °C. MMCO warmth was driven by

707-529: A clade of large terrestrial predatory crocodyliformes distantly related to modern crocodilians, from which they likely diverged over 180 million years ago, are known from the Miocene of South America. The last Desmostylians thrived during this period before becoming the only extinct marine mammal order. The pinnipeds , which appeared near the end of the Oligocene, became more aquatic. A prominent genus

808-570: A cooler, drier climate. C 4 grasses, which are able to assimilate carbon dioxide and water more efficiently than C 3 grasses, expanded to become ecologically significant near the end of the Miocene between 6 and 7 million years ago, although they did not expand northward during the Late Miocene. The expansion of grasslands and radiations among terrestrial herbivores correlates to fluctuations in CO 2 . One study, however, has attributed

909-486: A good analogue for future warmer climates caused by anthropogenic global warming , with this being especially true of the global climate during the Middle Miocene Climatic Optimum (MMCO), because the last time carbon dioxide levels were comparable to projected future atmospheric carbon dioxide levels resulting from anthropogenic climate change was during the MMCO. The Ross Sea margin of

1010-435: A good model for a "living fossil". Eucalyptus fossil leaves occur in the Miocene of New Zealand , where the genus is not native today, but have been introduced from Australia . Both marine and continental fauna were fairly modern, although marine mammals were less numerous. Only in isolated South America and Australia did widely divergent fauna exist. In Eurasia, genus richness shifted southward to lower latitudes from

1111-454: A group of four young cinder cones NW of Las Pilas volcano. Since its initial eruption in 1850, it has erupted more than 20 times, most recently in 1995 and 1999. Satellite images suggest that cinder cones occur on other terrestrial bodies in the solar system. On Mars, they have been reported on the flanks of Pavonis Mons in Tharsis , in the region of Hydraotes Chaos on the bottom of

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1212-430: A larger area. Therefore, it seems that erupted amount of material is not sufficient on Mars for the flank slopes to attain the angle of repose and Martian cinder cones seem to be ruled mainly by ballistic distribution and not by material redistribution on flanks as typical on Earth. Cinder cones often are highly symmetric, but strong prevailing winds at the time of eruption can cause a greater accumulation of cinder on

1313-406: A lava dome on the northern flank while the last formed a lava flow on Mount Hasan's western foot. A shift in archeological sites around Mount Hasan may be linked to the older eruptions. There is no evidence of historical eruptions of the volcano. Hydrothermal activity also occurs at Mount Hasan, with fumaroles and water vapour emissions on the summit. The emission occurs along vents trending in

1414-598: A major expansion of Antarctic glaciers. This severed the connection between the Indian Ocean and the Mediterranean Sea and formed the present land connection between Afro-Arabia and Eurasia. The subsequent uplift of mountains in the western Mediterranean region and a global fall in sea levels combined to cause a temporary drying up of the Mediterranean Sea (known as the Messinian salinity crisis ) near

1515-480: A major expansion of grass-grazer ecosystems . Herds of large, swift grazers were hunted by predators across broad sweeps of open grasslands , displacing desert, woodland, and browsers . The higher organic content and water retention of the deeper and richer grassland soils , with long-term burial of carbon in sediments, produced a carbon and water vapor sink. This, combined with higher surface albedo and lower evapotranspiration of grassland, contributed to

1616-541: A northeast-southwest direction, which are linked to a major regional fault . Rocks around these vents have been chemically altered. Another field of fumaroles and hot springs is on the northwestern side of Hasan. Magnetotelluric and other imaging techniques have found evidence of a magma chamber at 4–6 kilometres (2.5–3.7 mi) depth and of a magmatic body between 6–11.5 kilometres (3.7–7.1 mi). A hydrothermal system may or may not exist. There have been seismic swarms around Mount Hasan, including one in 2020 next to

1717-602: A significant drop in atmospheric carbon dioxide levels. Both continental and oceanic thermal gradients in mid-latitudes during the Early Miocene were very similar to those in the present. Global cooling caused the East Asian Summer Monsoon (EASM) to begin to take on its modern form during the Early Miocene. From 22.1 to 19.7 Ma, the Xining Basin experienced relative warmth and humidity amidst

1818-700: A significant local decline along the northeastern coast of Australia during the Tortonian, most likely due to warming seawater. Cetaceans attained their greatest diversity during the Miocene, with over 20 recognized genera of baleen whales in comparison to only six living genera. This diversification correlates with emergence of gigantic macro-predators such as megatoothed sharks and raptorial sperm whales . Prominent examples are O. megalodon and L. melvillei . Other notable large sharks were O. chubutensis , Isurus hastalis , and Hemipristis serra . Crocodilians also showed signs of diversification during

1919-415: A volcanic eruption, commonly linked to Mount Hasan, and this mural has even been interpreted as being the oldest known map . The interpretation of the mural showing a volcanic eruption has been contested however as an alternative interpretation is that the "volcano" shown in the mural is actually a leopard and the "village" a set of random geometric motifs. The map interpretation is also contested. The mural

2020-437: A younger calc-alkaline or alkaline suite. These rocks in turn include amphibole , apatite , biotite , clinopyroxene , garnet , ilmenite , mica , olivine , orthopyroxene , plagioclase , pyroxene in the form of augite , bronzite , diopside , hypersthene and salite , and quartz . The older volcanic stages have produced basaltic andesite while dacite appears only in the most recent stage. Obsidian also occurs in

2121-651: A zone of low rainfall in the Late Miocene. The Indian Plate continued to collide with the Eurasian Plate , creating new mountain ranges and uplifting the Tibetan Plateau , resulting in the rain shadowing and aridification of the Asian interior. The Tian Shan experienced significant uplift in the Late Miocene, blocking westerlies from coming into the Tarim Basin and drying it as a result. At

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2222-510: Is a small sized volcano with a caldera which crops out on the southwestern side of Mount Hasan. It grew over sediments to a present-day elevation of 1,700 metres (5,600 ft); today it is eroded, partly buried by the younger Hasan volcanics and disrupted by strike-slip faulting . About 7 million years ago the Paleovolcano began to grow north of Keçikalesi ; it too is buried by more recent volcanics but part of its deposits crop out on

2323-486: Is about 400 millimetres (16 in). Between October/November and May, the mountain is frequently covered by snow due to the common precipitation at that time and when it melts the water mostly infiltrates into the permeable rocks, making the volcano a principal groundwater recharge area in the region. Additionally, volcanics of Mount Hasan form a major aquifer and the Melendiz River passes north and northeast of

2424-405: Is characterized by slumping and blasts that destroy the original rim, while the fourth stage is characterized by the buildup of talus beyond the zone where cinder falls to the surface (the ballistic zone ). During the waning stage of a cinder cone eruption, the magma has lost most of its gas content. This gas-depleted magma does not fountain but oozes quietly into the crater or beneath the base of

2525-548: Is depicted in the Museum of Anatolian Civilizations in Ankara . If the mural indeed shows an eruption, it probably occurred only a short time before the mural was drawn. Radiocarbon dating has yielded ages of about 7,400 - 6,600 years BCE for Çatalhöyük and radiometric dating has produced evidence for explosive eruptions during that time and when the mural was made. The depicted activity resembles Strombolian eruptions , and

2626-522: Is formed by phreatomagmatic breccias , ignimbrites , lahar deposits, lava domes , lava flows and pyroclastic flow deposits. The pyroclastic flow deposits occur in the form of fans or valley flows, when they were channelled by topography. The northern flanks also feature two debris avalanche deposits with hummocky surfaces. Two calderas, the Ulukışla caldera on the eastern and the Keçikalesi on

2727-682: Is of particular interest to geologists and palaeoclimatologists because major phases of the geology of the Himalaya occurred during that epoch, affecting monsoonal patterns in Asia, which were interlinked with glacial periods in the northern hemisphere. The Miocene faunal stages from youngest to oldest are typically named according to the International Commission on Stratigraphy : Regionally, other systems are used, based on characteristic land mammals; some of them overlap with

2828-558: Is the source of a lava flow . Whether they are located within a caldera is unclear; rather than one large caldera encompassing the entire complex, there may be a smaller one underlying Mount Hasan specifically. There is periglacial activity on the summit, and fossil rock glaciers are found on the volcano. The volcano as a whole rises almost 1 kilometre (0.62 mi) around the surrounding terrain and covers an area of 760 square kilometres (290 sq mi) with 354 cubic kilometres (85 cu mi) of rocks. The terrain of Mount Hasan

2929-488: Is widely accepted to be in dedication to Ebu'l-Gazi (El-Hasan), brother of Ebu'l-Kasım during the reign of the Anatolian Seljuks . It is hypothesized that Mount Hasan’s name was “ Argeos ” or “ Argaios ”, but this name belongs to Mount Erciyes . Another hypothesis is that it was simply called Árgos , ( Ancient Greek : Ἄργος) as well as Argeiopolis Mons. The Hittites called it Athar . Mount Hasan lies in

3030-577: The Belbaşhanı Pumice and deposited fallout over much of Central Anatolia. Small Mount Hasan is probably older as it is more heavily eroded while the morphology of Big Hasan Dagi is fresher although its pyroclastic flow deposits are heavily incised. Dates of 33,000 and 29,000 years ago have been obtained on the summit domes and ages of 66,000±7,000 years on the most recent monogenetic volcano south of Mount Hasan. Explosive eruptions took place 28,900 ± 1,500 and 13,500 ± 1,500 years ago. Tephras found in

3131-728: The Coprates Chasma , or in the volcanic field Ulysses Colles . It is also suggested that domical structures in Marius Hills (on the Moon) might represent lunar cinder cones. The size and shape of cinder cones depend on environmental properties as different gravity and/or atmospheric pressure might change the dispersion of ejected scoria particles. For example, cinder cones on Mars seem to be more than two times wider than terrestrial analogues as lower atmospheric pressure and gravity enable wider dispersion of ejected particles over

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3232-744: The East Anatolian Fault . This movement and the resulting tectonic deformation of Anatolia are responsible for volcanism in Central Anatolia, together with the subduction of the Cyprus Plate . Volcanism has been ongoing for the past 10 million years; it is defined as "post-collisional". Further, volcanism at Mount Hasan has been related to the Tuz Gölü Fault and its intersection with the Karaman-Aksaray faults;

3333-529: The Konya plain and in a lake of the Turkish Lakes Region have been attributed to Mount Hasan. The debris flow from Mount Hasan occurred 150,000-100,000 years ago and a number of lava flows were emplaced during the last 100,000 years. Eruptions occurred 8,970 ± 640, 8,200, less than 6,000 years ago and 0 ± 3,000 years ago; the first emplaced pumice on the summit, the penultimate of these formed

3434-559: The Middle Miocene Climate Transition (MMCT). Abrupt increases in opal deposition indicate this cooling was driven by enhanced drawdown of carbon dioxide via silicate weathering. The MMCT caused a sea surface temperature (SST) drop of approximately 6 °C in the North Atlantic. The drop in benthic foraminiferal δ O values was most noticeable in the waters around Antarctica, suggesting cooling

3535-543: The Plio-Pleistocene and into the Quaternary . The volcano has two summits, the 3,069 metres (10,069 ft) high eastern Small Hasan Dagi/ Küçük Hasandağ and the 3,253 metres (10,673 ft) high Big Hasan Dagi/ Büyük Hasandağ , and consist of lava domes and lava flows . Big Hasan Dagi has two nested craters with an 800 metres (2,600 ft) wide and 200 metres (660 ft) high inner cone that

3636-619: The Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages . The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing

3737-742: The Taurus Mountains to the Byzantine capital Constantinople . Miocene The Miocene ( / ˈ m aɪ . ə s iː n , - oʊ -/ MY -ə-seen, -⁠oh- ) is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago (Ma). The Miocene was named by Scottish geologist Charles Lyell ; the name comes from the Greek words μείων ( meíōn , "less") and καινός ( kainós , "new") and means "less recent" because it has 18% fewer modern marine invertebrates than

3838-560: The carbon cycle occurred approximately 6 Ma, causing continental carbon reservoirs to no longer expand during cold spells, as they had done during cold periods in the Oligocene and most of the Miocene. At the end of the Miocene, global temperatures rose again as the amplitude of Earth's obliquity increased, which caused increased aridity in Central Asia. Around 5.5 Ma, the EAWM underwent a period of rapid intensification. Life during

3939-491: The mantle with participation of crustal components. Evidence of fractional crystallization has been encountered in the most recent stage rocks and more generally plays a role in the genesis of Hasan magmas although it does not explain all of the compositional traits. It appears that basaltic andesites formed through mixing, while fractional crystallization was more important for the genesis of other magmas. Older volcanic stages also show evidence of subduction influence while

4040-636: The Anatolian plateau, between the Taurus Range and the Pontic Mountains , and its and Mount Erciyes 's silhouettes dominate the landscape and rise high above the surrounding terrain. The city of Aksaray lies 30–40 kilometres (19–25 mi) northwest from Mount Hasan, while the settlements of Helvadere , Uluören , Dikmen and Taşpınar lie clockwise from north to northwest around the volcano. In addition, there are seasonal settlements on

4141-710: The Central Paratethys, cut off from sources of freshwater input by its separation from the Eastern Paratethys. From 13.36 to 12.65 Ma, the Central Paratethys was characterised by open marine conditions, before the reopening of the Bârlad Strait resulted in a shift to brackish-marine conditions in the Central Paratethys, causing the Badenian-Sarmatian Extinction Event. As a result of the Bârlad Strait's reopening,

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4242-837: The Early to the Middle Miocene. Europe's large mammal diversity significantly declined during the Late Miocene. In the Early Miocene, several Oligocene groups were still diverse, including nimravids , entelodonts , and three-toed equids. As in the previous Oligocene Epoch, oreodonts were still diverse, only to disappear in the earliest Pliocene. During the later Miocene mammals were more modern, with easily recognizable canids , bears , red pandas , procyonids , equids , beavers , deer , camelids , and whales , along with now-extinct groups like borophagine canids , certain gomphotheres , three-toed horses , and hornless rhinos like Teleoceras and Aphelos . The late Miocene also marks

4343-720: The East Antarctic Ice Sheet (EAIS) was highly dynamic during the Early Miocene. The Miocene began with the Early Miocene Cool Event (Mi-1) around 23 million years ago, which marked the start of the Early Miocene Cool Interval (EMCI). This cool event occurred immediately after the Oligocene-Miocene Transition (OMT) during a major expansion of Antarctica's ice sheets, but was not associated with

4444-545: The East Asian Winter Monsoon (EAWM) became stronger synchronously with a southward shift of the subarctic front. Greenland may have begun to have large glaciers as early as 8 to 7 Ma, although the climate for the most part remained warm enough to support forests there well into the Pliocene. Zhejiang, China was noticeably more humid than today. In the Great Rift Valley of Kenya , there

4545-535: The Kirshehir and Nigde massifs. The surface however consists mainly of Tertiary volcanic rocks, which are formed both by numerous ignimbrites , volcaniclastic material and individual volcanoes. Central Anatolia has undergone uplift, for which several mechanisms have been proposed. Mount Hasan has produced volcanic rocks with compositions ranging from basalt to rhyolite but the dominant components are andesite and dacite which define an older tholeiitic and

4646-460: The LMC; extratropical sea surface temperatures dropped substantially by approximately 7–9 °C. 41 kyr obliquity cycles became the dominant orbital climatic control 7.7 Ma and this dominance strengthened 6.4 Ma. Benthic δ O values show significant glaciation occurred from 6.26 to 5.50 Ma, during which glacial-interglacial cycles were governed by the 41 kyr obliquity cycle. A major reorganisation of

4747-579: The Late Cretaceous, are known from the Miocene of Patagonia, represented by the mole-like Necrolestes . The youngest known representatives of metatherians (the broader grouping to which marsupials belong) in Europe, Asia and Africa are known from the Miocene, including the European herpetotheriid Amphiperatherium , the peradectids Siamoperadectes and Sinoperadectes from Asia, and

4848-705: The Late Miocene, the Earth's climate began to display a high degree of similarity to that of the present day . The 173 kyr obliquity modulation cycle governed by Earth's interactions with Saturn became detectable in the Late Miocene. By 12 Ma, Oregon was a savanna akin to that of the western margins of the Sierra Nevada of northern California . Central Australia became progressively drier, although southwestern Australia experienced significant wettening from around 12 to 8 Ma. The South Asian Winter Monsoon (SAWM) underwent strengthening ~9.2–8.5 Ma. From 7.9 to 5.8 Ma,

4949-574: The Miocene Epoch was mostly supported by the two newly formed biomes , kelp forests and grasslands . Grasslands allow for more grazers, such as horses , rhinoceroses , and hippos . Ninety-five percent of modern plants existed by the end of this epoch . Modern bony fish genera were established. A modern-style latitudinal biodiversity gradient appeared ~15 Ma. The coevolution of gritty , fibrous, fire-tolerant grasses and long-legged gregarious ungulates with high-crowned teeth , led to

5050-449: The Miocene. The largest form among them was a gigantic caiman Purussaurus which inhabited South America. Another gigantic form was a false gharial Rhamphosuchus , which inhabited modern age India . A strange form, Mourasuchus also thrived alongside Purussaurus . This species developed a specialized filter-feeding mechanism, and it likely preyed upon small fauna despite its gigantic size. The youngest members of Sebecidae ,

5151-698: The Miocene–Pliocene boundary, the Strait of Gibraltar opened, and the Mediterranean refilled. That event is referred to as the " Zanclean flood ". Also during the early Miocene (specifically the Aquitanian and Burdigalian Stages), the apes first evolved, began diversifying, and became widespread throughout the Old World . Around the end of this epoch, the ancestors of humans had split away from

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5252-488: The Niğde Volcanic Complex, a mountain range , which is surrounded by plains and whose summits reach heights of over 3,000 metres (9,800 ft). Of these mountains, Melendiz Dağ is more heavily eroded compared to the steep cones of Hasan and like Keçiboyduran is of early Pliocene age. This alignment is congruent with the tectonic patterns of Anatolia, where the collision between Africa and Eurasia follows

5353-550: The North American Great Plains and in Argentina . The global trend was towards increasing aridity caused primarily by global cooling reducing the ability of the atmosphere to absorb moisture, particularly after 7 to 8 million years ago. Uplift of East Africa in the late Miocene was partly responsible for the shrinking of tropical rain forests in that region, and Australia got drier as it entered

5454-656: The Oligocene–Miocene transgression. As the southern Andes rose in the Middle Miocene (14–12 million years ago) the resulting rain shadow originated the Patagonian Desert to the east. Far northern Australia was monsoonal during the Miocene. Although northern Australia is often believed to have been much wetter during the Miocene, this interpretation may be an artefact of preservation bias of riparian and lacustrine plants; this finding has itself been challenged by other papers. Western Australia, like today,

5555-561: The Qiongdongnan Basin in the northern South China Sea indicates the Pearl River was a major source of sediment flux into the sea during the Early Miocene and was a major fluvial system as in the present. During the Oligocene and Early Miocene, the coast of northern Brazil, Colombia, south-central Peru , central Chile and large swathes of inland Patagonia were subject to a marine transgression . The transgressions in

5656-497: The activity of the Columbia River Basalts and enhanced by decreased albedo from the reduction of deserts and expansion of forests. Climate modelling suggests additional, currently unknown, factors also worked to create the warm conditions of the MMCO. The MMCO saw the expansion of the tropical climatic zone to much larger than its current size. The July ITCZ, the zone of maximal monsoonal rainfall, moved to

5757-412: The air and then cooled quickly. Lava fragments larger than 64 mm across, known as volcanic bombs , are also a common product of cinder cone eruptions. The growth of a cinder cone may be divided into four stages. In the first stage, a low-rimmed scoria ring forms around the erupting event. During the second stage, the rim is built up and a talus slope begins to form outside the rim. The third stage

5858-531: The ancestors of the chimpanzees and had begun following their own evolutionary path during the final Messinian Stage (7.5–5.3 Ma) of the Miocene. As in the Oligocene before it, grasslands continued to expand, and forests to dwindle. In the seas of the Miocene, kelp forests made their first appearance and soon became one of Earth's most productive ecosystems. The plants and animals of the Miocene were recognizably modern. Mammals and birds were well established. Whales , pinnipeds , and kelp spread. The Miocene

5959-472: The aridity of the former. Unequivocally-recognizable dabbling ducks , plovers , typical owls , cockatoos and crows appear during the Miocene. By the epoch's end, all or almost all modern bird groups are believed to have been present; the few post-Miocene bird fossils which cannot be placed in the evolutionary tree with full confidence are simply too badly preserved, rather than too equivocal in character. Marine birds reached their highest diversity ever in

6060-462: The base of the crust , while the other volcanic rocks have shallower sources. The basaltic magmas would have ascended into a shallow magma chamber at 3–4 kilometres (1.9–2.5 mi) depth, mobilizing its contents and thus giving rise to the more silicic magmas. The magma formation processes were quick, with only days or weeks going from the formation of the magma and its eruption on the surface. Oak forests occur on Mount Hasan. Annual precipitation

6161-638: The beginning of the Miocene, the northern margin of the Arabian plate, then part of the African landmass, collided with Eurasia; as a result, the Tethys seaway continued to shrink and then disappeared as Africa collided with Eurasia in the Turkish – Arabian region. The first step of this closure occurred 20 Ma, reducing water mass exchange by 90%, while the second step occurred around 13.8 Ma, coincident with

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6262-473: The cone as lava. Lava rarely issues from the top (except as a fountain) because the loose, uncemented cinders are too weak to support the pressure exerted by molten rock as it rises toward the surface through the central vent. Because it contains so few gas bubbles, the molten lava is denser than the bubble-rich cinders. Thus, it often burrows out along the bottom of the cinder cone, lifting the less dense cinders like corks on water, and advances outward, creating

6363-478: The connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and hominoids into Eurasia. During the late Miocene, the connections between the Atlantic and Mediterranean closed, causing the Mediterranean Sea to almost completely evaporate. This event is referred to as the " Messinian salinity crisis ". Then, at

6464-577: The course of this epoch . The youngest representatives of Choristodera , an extinct order of aquatic reptiles that first appeared in the Middle Jurassic , are known from the Miocene of Europe, belonging to the genus Lazarussuchus , which had been the only known surviving genus of the group since the beginning of the Eocene. The last known representatives of the archaic primitive mammal order Meridiolestida , which dominated South America during

6565-705: The downwind side of the vent. Some cinder cones are monogenetic , forming from a single short eruptive episode that produces a very small volume of lava. The eruption typically last just weeks or months, but can occasionally last fifteen years or longer. Parícutin in Mexico, Diamond Head , Koko Head , Punchbowl Crater , Mt Le Brun from the Coalstoun Lakes volcanic field , and some cinder cones on Mauna Kea are monogenetic cinder cones. However, not all cinder cones are monogenetic, with some ancient cinder cones showing intervals of soil formation between flows that indicate that eruptions were separated by thousands to tens of thousands of years. Monogenetic cones likely form when

6666-524: The early to mid Miocene (23–15 Ma). Oceans cooled partly due to the formation of the Antarctic Circumpolar Current , and about 15 million years ago the ice cap in the southern hemisphere started to grow to its present form. The Greenland ice cap developed later, in the Middle Pliocene time, about 3 million years ago. Cinder cone A cinder cone (or scoria cone ) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around

6767-451: The end of the Miocene due to increased habitat uniformity. The expansion of grasslands in North America also led to an explosive radiation among snakes. Previously, snakes were a minor component of the North American fauna, but during the Miocene, the number of species and their prevalence increased dramatically with the first appearances of vipers and elapids in North America and the significant diversification of Colubridae (including

6868-422: The end of the Miocene. The Paratethys underwent a significant transgression during the early Middle Miocene. Around 13.8 Ma, during a global sea level drop, the Eastern Paratethys was cut off from the global ocean by the closure of the Bârlad Strait, effectively turning it into a saltwater lake. From 13.8 to 13.36 Ma, an evaporite period similar to the later Messinian salinity crisis in the Mediterranean ensued in

6969-429: The enigmatic Saint Bathans Mammal . Microbial life in the igneous crust of the Fennoscandian Shield shifted from being dominated by methanogens to being primarily composed of sulphate-reducing prokaryotes . The change resulted from fracture reactivation during the Pyrenean-Alpine orogeny, enabling sulphate-reducing microbes to permeate into the Fennoscandian Shield via descending surficial waters. Diatom diversity

7070-527: The erupted lava is enriched in sodium and potassium oxides . Cinder cones are also commonly found on the flanks of shield volcanoes , stratovolcanoes , and calderas . For example, geologists have identified nearly 100 cinder cones on the flanks of Mauna Kea , a shield volcano located on the island of Hawaii . Such cinder cones likely represent the final stages of activity of a mafic volcano. However, most volcanic cones formed in Hawaiian-type eruptions are spatter cones rather than cinder cones, due to

7171-433: The event may not have been directly visible from Çatalhöyük. The discovery of this mural has drawn attention to the volcano and has led to efforts to date the eruptive activity of Mount Hasan. Mount Hasan was used as a source for Obsidian . The Byzantine city of Mokissos was located on Mount Hasan. The mountain is considered to be the second beacon of the Byzantine beacon system , which was used to relay information from

7272-461: The evolution of both groups into modern representatives. The early Miocene Saint Bathans Fauna is the only Cenozoic terrestrial fossil record of the landmass, showcasing a wide variety of not only bird species, including early representatives of clades such as moa , kiwi and adzebills , but also a diverse herpetofauna of sphenodontians , crocodiles and turtles as well as a rich terrestrial mammal fauna composed of various species of bats and

7373-499: The expansion of grasslands not to a CO 2 drop but to the increasing seasonality and aridity, coupled with a monsoon climate, which made wildfires highly prevalent compared to before. The Late Miocene expansion of grasslands had cascading effects on the global carbon cycle, evidenced by the imprint it left in carbon isotope records. Cycads between 11.5 and 5 million years ago began to rediversify after previous declines in variety due to climatic changes, and thus modern cycads are not

7474-718: The extinction of the last-surviving members of the hyaenodonts . Islands began to form between South and North America in the Late Miocene, allowing ground sloths like Thinobadistes to island-hop to North America. The expansion of silica-rich C 4 grasses led to worldwide extinctions of herbivorous species without high-crowned teeth . Mustelids diversified into their largest forms as terrestrial predators like Ekorus , Eomellivora , and Megalictis and bunodont otters like Enhydriodon and Sivaonyx appeared. Eulipotyphlans were widespread in Europe, being less diverse in Southern Europe than farther north due to

7575-629: The findings of marine invertebrate fossils of both Atlantic and Pacific affinity in La Cascada Formation . Connection would have occurred through narrow epicontinental seaways that formed channels in a dissected topography . The Antarctic Plate started to subduct beneath South America 14 million years ago in the Miocene, forming the Chile Triple Junction . At first the Antarctic Plate subducted only in

7676-510: The fluid nature of the lava. The most famous cinder cone, Paricutin , grew out of a corn field in Mexico in 1943 from a new vent. Eruptions continued for nine years, built the cone to a height of 424 meters (1,391 ft), and produced lava flows that covered 25 km (9.7 sq mi). The Earth's most historically active cinder cone is Cerro Negro in Nicaragua. It is part of

7777-510: The former of these is one of two major fault systems in Central Anatolia which influence volcanism there, and volcanic products of Mount Hasan have been deformed by the fault. The Hasandag fault branches off the Karaman-Aksaray fault and cuts between the two summits of Mount Hasan. It and the Karacaören fault influence the hydrothermal system of the volcano. The westerly Mount Hasan, central Keçiboyduran and easterly Melendiz Dağ form

7878-464: The human lineage) appeared in Africa at the very end of the Miocene, including Sahelanthropus , Orrorin , and an early form of Ardipithecus ( A. kadabba ). The chimpanzee–human divergence is thought to have occurred at this time. The evolution of bipedalism in apes at the end of the Miocene instigated an increased rate of faunal turnover in Africa. In contrast, European apes met their end at

7979-606: The lake levels of the Eastern Paratethys dropped as it once again became a sea. The Fram Strait opened during the Miocene and acted as the only throughflow for Atlantic Water into the Arctic Ocean until the Quaternary period. Due to regional uplift of the continental shelf, this water could not move through the Barents Seaway in the Miocene. The modern day Mekong Delta took shape after 8 Ma. Geochemistry of

8080-501: The more recent magmas are more indicative of intraplate processes, the effects of crustal extension and of the presence of water. In general, various sources have been proposed for the magmas of the Central Anatolian province. The magmatic system of Mount Hasan appears to be more active than that of Mount Erciyes. The magmas formed at different depths, with basalts originating at about 35–41 kilometres (22–25 mi) depth at

8181-407: The most recent event 34,000 years ago. This volcanism however is not part of the actual Mount Hasan system. The main edifice has produced about 1–0.3 cubic kilometres (0.240–0.072 cu mi) of magma every millennium, more than at Erciyes. Keçikalesi is the oldest (13 million years) volcanic structure, it is among the oldest volcanoes of the Central Anatolian volcanic province. This volcano

8282-448: The most recent stage although it is not an important component while most of the rocks are porphyritic . The basaltic family includes both basaltic andesite and alkali basalts with augite , clinopyroxene , garnet , hornblende , hypersthene , olivine , orthopyroxene , oxides and plagioclase . Magma mixing processes appear to be the most important mechanisms involved in the genesis of Mount Hasan magmas , which are derived from

8383-547: The north, increasing precipitation over southern China whilst simultaneously decreasing it over Indochina during the EASM. Western Australia was at this time characterised by exceptional aridity. In Antarctica, average summer temperatures on land reached 10 °C. In the oceans, the lysocline shoaled by approximately half of a kilometre during warm phases that corresponded to orbital eccentricity maxima. The MMCO ended around 14 million years ago, when global temperatures fell in

8484-532: The northwestern flank of Mount Hasan in the form of ignimbrites, lahars and lava flows. The Paleovolcano also formed a caldera which produced the rhyolitic Dikmen-Taspinar Ignimbrites; formerly the Cappadocian tuffs were in general attributed to volcanism at Mount Hasan, Mount Erciyes and Göllü Dag . The Quaternary activity gave rise to the Mesovolcano and Neovolcano, with the former centered between

8585-523: The origin of many modern genera such as Nerodia , Lampropeltis , Pituophis and Pantherophis ). Arthropods were abundant, including in areas such as Tibet where they have traditionally been thought to be undiverse. Neoisopterans diversified and expanded into areas they previously were absent from, such as Madagascar and Australia. In the oceans, brown algae , called kelp , proliferated, supporting new species of sea life, including otters , fish and various invertebrates . Corals suffered

8686-463: The possible herpetotheriid Morotodon from the late Early Miocene of Uganda. Approximately 100 species of apes lived during this time , ranging throughout Africa, Asia and Europe and varying widely in size, diet, and anatomy. Due to scanty fossil evidence it is unclear which ape or apes contributed to the modern hominid clade, but molecular evidence indicates this ape lived between 18 and 13 million years ago. The first hominins ( bipedal apes of

8787-846: The preceding Oligocene and following Pliocene Epochs: Continents continued to drift toward their present positions. Of the modern geologic features, only the land bridge between South America and North America was absent, although South America was approaching the western subduction zone in the Pacific Ocean , causing both the rise of the Andes and a southward extension of the Meso-American peninsula. Mountain building took place in western North America , Europe , and East Asia . Both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in

8888-469: The rim of the Mesovolcano caldera that probably formed through the interaction of intruding magma with water in the caldera, 700,000 years ago rhyolitic flows and ignimbrites accompanied by the formation of another, 4 by 5 kilometres (2.5 mi × 3.1 mi) caldera, and finally andesitic lava flows and lava domes which form the two main summits. A major Plinian to sub-Plinian pumice -forming eruption took place 417,200 ± 20,500 years ago, forming

8989-505: The same trend. It and to some degree Mount Hasan are also surrounded by a large depression, and the volcanoes of this alignment are separated by faults. Additionally, Mount Hasan forms a volcanic lineament with Karadağ and the Karapınar Field . The basement in Central Anatolia is formed by magmatic, metamorphic and ophiolitic rocks, the former of which are of Paleozoic to Mesozoic age; it crops out at scattered sites and in

9090-714: The southernmost tip of Patagonia, meaning that the Chile Triple Junction lay near the Strait of Magellan . As the southern part of Nazca Plate and the Chile Rise became consumed by subduction the more northerly regions of the Antarctic Plate begun to subduct beneath Patagonia so that the Chile Triple Junction advanced to the north over time. The asthenospheric window associated to the triple junction disturbed previous patterns of mantle convection beneath Patagonia inducing an uplift of ca. 1 km that reversed

9191-525: The southwestern flank, adorn the volcano. The volcanics of Mount Hasan have been subdivided into a "hot flow" unit, a "Mt. Hasan ashes" unit and into a lava unit. Cinder cones , maars and accompanying lava flows also occur around Mount Hasan, they are part of a basaltic volcano family that forms parasitic vents . These include the Yıpraktepe cone/maar and a lava flow field at Karataş which covers an area of 60 square kilometres (23 sq mi) and

9292-524: The two present-day summits. This volcano produced ignimbrites, lava domes and lava flows and eventually a caldera ; it too has been dissected by faulting which probably also influenced the development of the volcano and its activity probably occurred between 1 and 0.15 million years ago. Finally, the Neovolcano grew within the caldera, producing various kinds of deposits; these include lava domes with accompanying pyroclastic flow deposits, breccia in

9393-574: The volcano which are associated with summer pastures . The volcano has been prospected as a potential source for geothermal power . Mount Hasan is part of a larger volcanic province in Central Anatolia known as the Central Anatolian or Cappadocian Volcanic Province., which includes ignimbrites , monogenetic volcanic fields and stratovolcanoes such as Mount Erciyes , Mount Hasan, Karacadağ and Melendiz Dağ with an area of about 20,000 square kilometres (7,700 sq mi)-25,000 square kilometres (9,700 sq mi). Volcanism took place during

9494-451: The volcano. Mount Hasan has been active for the last 13 million years, with the Keçikalesi , Paleo-Hasan, Mesovolcano and Neovolcano stages during the Miocene , Miocene- Pliocene and Quaternary ; the older two stages might actually not be part of Mount Hasan at all. Aside from the felsic central vent volcanism, basaltic volcanism also took place at Mount Hasan throughout its activity; this activity has been dated to 120,000, 65,000 and

9595-604: The west coast of South America are thought to be caused by a regional phenomenon while the steadily rising central segment of the Andes represents an exception. While there are numerous registers of Oligocene–Miocene transgressions around the world it is doubtful that these correlate. It is thought that the Oligocene–Miocene transgression in Patagonia could have temporarily linked the Pacific and Atlantic Oceans, as inferred from

9696-423: Was Allodesmus . A ferocious walrus , Pelagiarctos may have preyed upon other species of pinnipeds including Allodesmus . Furthermore, South American waters witnessed the arrival of Megapiranha paranensis , which were considerably larger than modern age piranhas . New Zealand 's Miocene fossil record is particularly rich. Marine deposits showcase a variety of cetaceans and penguins , illustrating

9797-624: Was a gradual and progressive trend of increasing aridification, though it was not unidirectional, and wet humid episodes continued to occur. Between 7 and 5.3 Ma, temperatures dropped sharply again in the Late Miocene Cooling (LMC), most likely as a result of a decline in atmospheric carbon dioxide and a drop in the amplitude of Earth's obliquity, and the Antarctic ice sheet was approaching its present-day size and thickness. Ocean temperatures plummeted to near-modern values during

9898-464: Was arid, particularly so during the Middle Miocene. Climates remained moderately warm, although the slow global cooling that eventually led to the Pleistocene glaciations continued. Although a long-term cooling trend was well underway, there is evidence of a warm period during the Miocene when the global climate rivalled that of the Oligocene . The climate of the Miocene has been suggested as

9999-688: Was inversely correlated with carbon dioxide levels and global temperatures during the Miocene. Most modern lineages of diatoms appeared by the Late Miocene. There is evidence from oxygen isotopes at Deep Sea Drilling Program sites that ice began to build up in Antarctica about 36 Ma during the Eocene . Further marked decreases in temperature during the Middle Miocene at 15 Ma probably reflect increased ice growth in Antarctica. It can therefore be assumed that East Antarctica had some glaciers during

10100-646: Was most intense there. Around this time the Mi3b glacial event (a massive expansion of Antarctic glaciers) occurred. The East Antarctic Ice Sheet (EAIS) markedly stabilised following the MMCT. The intensification of glaciation caused a decoherence of sediment deposition from the 405 kyr eccentricity cycle. The MMWI ended about 11 Ma, when the Late Miocene Cool Interval (LMCI) started. A major but transient warming occurred around 10.8-10.7 Ma. During

10201-589: Was produced by fissure vents . Many of the cones around Mount Hasan have been grouped as the Hasandağ-Karacadağ volcanic field. As a consequence of the subduction and eventual closure of the Neo-Tethys and continental collision between Arabia - Africa and Eurasia , Anatolia moves westward at a rate of 21 millimetres per year (0.83 in/year) between the North Anatolian Fault and

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