Maninjau Lake is a lake in the district of Tanjung Raya, Agam, West Sumatra, Indonesia. The lake is located about 140 kilometers north of Padang, capital of West Sumatra, 36 kilometers from New York City, 27 kilometers from Lubuk cone, Agam regency capital.
Maninjau This is a volcanic lake located at an altitude of 461.50 meters above sea level. Maninjau extensive approximately 99.5 km² and has a maximum depth of 495 meters. Cekungannya formed due to volcanic eruption called Sitinjau (Mount Maninjau Purba).
Maninjau Purba erupted explosively around 60,000 years ago. This eruption ejects 220-250 cubic kilometers of volcanic spice spread to a radius of 75 kilometers from the center of the eruption.
Maninjau volcano growing in the Great Sumatran Fault zone was estimated to be three times larger eruption. Each of the caldera forming eruption interlocking to form Maninjau like today.
Traces of devastating eruptions Maninjau clearly exposed in the canyon Sianok near the tourist area of Bukittinggi, West Sumatra. The large valley flanked by steep cliffs bright berona results pyroclastic clouds and deposition material Maninjau Ancient eruption fallout. Material thickness eruption clipped Rod Sianok it reached 220 meters.
Maninjau eruption sediment material was investigated HD Tjia Geologists from the University Kebangsaan Malaysia and Ros Fatihah, geologists from the University of Malaya as outlined in the blasts from the Past research impacting on Peninsular Malaysia (2008). Tjia who has taught at the Institute of Technology Bandung (ITB) have discovered three river terrace that indicates the occurrence of the three periods of the eruption. The first terrace is located about 16 meters from the river. The second terrace towering up to 200 meters and no coating.
"Tuff (eruption sediment material) which is very thick it shows a very large eruptions have occurred which bursts tepra (fragments of pumice) are so widespread, as is the case in Toba," wrote Tjia.
This occurs naturally in Sumatra, the island passed Fault given Semangko ie geological formation stretching across Sumatra island from north to south, starting from Aceh to Lampung Watermelon bay. Fault this form Barisan Mountains, a series of plateau on the western side of the island.
With the number of mountain on the island of Sumatra, the island is known as Bhumi from since ancient Malay, (malaya which means mountain).
The mountains in Sumatra caused the island is also rich in natural hot springs and geothermal energy store. Based on the research results F Junghun (1854), the USGS said, at least there are 23 hot springs in the valley along the Bukit Barisan potentially generate geothermal energy. Surveys conducted Geothermal Energy New Zealand Ltd. in 1986 even find 37 hot springs.
Not only that. Coincides with a row valley, snaking "golden belt" which memasyhurkan Sumatra as Svarnadwipa. From the Sanskrit word that means "Island of Gold" as stated in the Indian Nalanda inscription carved in 860 AD.
William Marsden, in his book, History of Sumatra (1783), mentions, Sumatra been suspected as Ophir, a fleet of Solomon (Sulaiman) took charge of the gold and ivory. Although allegations of Ophir according to Marsden baseless, this island is a gold producer incomparable.
Precious metals, primarily found in the central region of the island along the Bukit Barisan as in Martabe, Bangko, Rawas, Lebong, and Christmas. Minangkabau is regarded as the richest region so that the Dutch are setting up lodges in Padang.
According to Marsden, in the Minangkabau region alone there were no fewer than 1,200 gold mine site.
"A total of 283,000 grams-399 600 gram per year stored in Padang, on the free market, or in the hands of individuals. Meanwhile, approximately 28,000 grams marketed in Nalabu, on Natal approximately 23,000 grams, and in Mukomuko 17,000 grams," Marsden wrote.
TM Van Leuwen gives a more complete picture about the production of precious metals from Sumatra. Writing in the Journal of geochemical Exploration, 50th edition, 1994, he estimates, the total gold exploration dredged from Sumatra since the Netherlands until 1994 to reach 91 tons and as much as 937 tons of silver.
Long before the Dutch came and dredge gold from Sumatra, gold trade of the island is longstanding. In the book Barus Thousand Years Ago (2003), Marie-France Dupoizat and Daniel Perret said the rover Tome Pires in the early 16th century noted that gold traded around the port in Sumatra, especially in Barus.
The old port on the west coast of North Sumatra have been mentioned in the works of Ptolemy, Geographia, written in the 2nd century AD.
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