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Indochinite
An Indochinite is a type of tektite. Tektites were ejected into the Earth's upper atmosphere by a meteorite impact and subsequently cooled to form the distinctive glass-like structure. Indochinites are distinctly dark black in contrast to the green of European moldavite tektites. It is estimated that these bodies of solidified magma are 700,000 years old. Indochinite tektites, as the name suggests, are found in the Indochinese peninsula, from Australia and the Pacific islands of Micronesia in the east and south, to China and Indonesia in the north and west. The largest indochinite is a Muong-Nong type tektite (which are layered tektites), which had a mass of 29.0 kg. See also *Australasian strewnfield The Australasian strewnfield is the youngest and largest of the tektite strewnfields, with recent estimates suggesting it might cover 10%–30% of the Earth's surface.Glass, B.P. and Wu, J., 1993. ''Coesite and shocked quartz discovered in the, ... References External li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tektite With Bubble Cavity
Tektites () are gravel-sized bodies composed of black, green, brown or grey natural glass formed from terrestrial debris ejected during meteorite impacts. The term was coined by Austrian geologist Franz Eduard Suess (1867–1941), son of Eduard Suess. They generally range in size from millimetres to centimetres. Millimetre-scale tektites are known as microtektites.French, B. M. (1998) ''Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures.'' LPI Contribution No. 954. Lunar and Planetary Institute, Houston, Texas. 120 pp.McCall, G. J. H. (2001) ''Tektites in the Geological Record: Showers of Glass from the Sky.'' The Geological Society Publishing House, Bath, United Kingdom. 256 pp. Montanari, A., and C. Koeberl (2000) ''Impact Stratigraphy. The Italian Record.'' Lecture Notes in Earth Sciences Series no. 93. Springer-Verlag, New York, New York. 364 pp. Tektites are characterized by: # a fairly homogeneous composition # an ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moldavite
Moldavite () is a forest green, olive green or blue greenish vitreous silica projectile glass formed by a meteorite impact in southern Germany ( Nördlinger Ries Crater) that occurred about 15 million years ago. It is a type of tektite and a gemstone. Material ejected from the impact crater includes moldavite, which was strewn across parts of Germany, the Czech Republic and Austria. Early studies Moldavite was introduced to the scientific public for the first time in 1786 as "chrysolites" from Týn nad Vltavou in a lecture by Josef Mayer of Prague University, read at a meeting of the Bohemian Scientific Society (Mayer 1788). Zippe (1836) first used the term "moldavite", derived from the Vltava (Moldau) river in Bohemia (the Czech Republic), from where the first described pieces came. Origin In 1900, Franz Eduard Suess pointed out that the gravel-size moldavites exhibited curious pittings and wrinkles on the surface, which could not be due to the action of water, but resemble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indochinese Peninsula
Mainland Southeast Asia (historically known as Indochina and the Indochinese Peninsula) is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west and the Pacific Ocean to the east. It includes the countries of Cambodia, Laos, Myanmar, Singapore, Thailand and Vietnam as well as Peninsular Malaysia. The term ''Indochina'' (originally ''Indo-China'') was coined in the early nineteenth century, emphasizing the historical cultural influence of Indian and Chinese civilizations on the region. The term was later adopted as the name of the colony of French Indochina (present-day Cambodia, Laos, and Vietnam). Today, the term "Mainland Southeast Asia" is more commonly used, in contrast to Maritime Southeast Asia for the island groups off the coast of the peninsula. Terminology In Indian sources, the earliest name connected with Southeast Asia is . Another possible early name of mai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micronesia
Micronesia (, ) is a subregion of Oceania, consisting of approximately 2,000 small islands in the Northwestern Pacific Ocean. It has a close shared cultural history with three other island regions: Maritime Southeast Asia to the west, Polynesia to the east, and Melanesia to the south—as well as with the wider community of Austronesian peoples. The region has a tropical marine climate and is part of the Oceanian realm. It includes four main archipelagos—the Caroline Islands, the Gilbert Islands, the Mariana Islands, and the Marshall Islands — as well as numerous islands that are not part of any archipelago. Political control of areas within Micronesia varies depending on the island, and is distributed among six sovereign nations. Some of the Caroline Islands are part of the Republic of Palau and some are part of the Federated States of Micronesia (often shortened to "FSM" or "Micronesia"—not to be confused with the identical name for the overall region). The Gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australasian Strewnfield
The Australasian strewnfield is the youngest and largest of the tektite strewnfields, with recent estimates suggesting it might cover 10%–30% of the Earth's surface.Glass, B.P. and Wu, J., 1993. ''Coesite and shocked quartz discovered in the, Australasian and North American, microtektite layers.'' ''Geology'', 21(5), pp.435-438.Prasad, M.S., Gupta, S.M. and Kodagali, V.N., 2003. ''Two layers of Australasian impact ejecta in the Indian Ocean?.'' ''Meteoritics & Planetary Science'', 38(9), pp.1373-1381.Prasad, M.S., Mahale, V.P. and Kodagali, V.N., 2007. ''New sites of Australasian microtektites in the central Indian Ocean: Implications for the location and size of source crater.'' ''Journal of Geophysical Research: Planets'', 112, no. E06007, 11 pp. Research indicates that the impact forming the tektites occurred around 788,000 years ago, most likely in Southeast Asia.Jourdan, F., Nomade, S., Wingate, M.T., Eroglu, E. and Deino, A., 2019. ''Ultraprecise age and formation tempera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
