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2004-01-01
View of the area at Deception Island, off the Antarctic Peninsula, where Sir Hubert Wilkins made the first flight in Antarctica in 1928. Deception Island is a drowned caldera (volcanic crater) covered in black volcanic sand from the last eruption in 1970. The heat remaining in the sand warms the...
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2016-01-01
Throughout the world, high artesian pressures in hydrothermal areas have led to the growth of tall spring towers that have their vents at their summits. The factors that control their development and formative precipitates are poorly understood because these springs, irrespective of location, are...
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Laminae development in opal-A precipitates associated with seasonal growth of the form-genus Calothrix (Cyanobacteria), Rehai geothermal area, Tengchong, Yunnan Province, China.
Download2015-01-01
The western discharge apron at Meinuquan (Rehai geothermal area, Yunnan Province, China), which incorporates the upper terrace, terrace front, and lower terrace, is covered with laminated opal-A precipitates that have formed from the spring waters that flow across its surface. Laminae are formed...
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Mineralogical, crystallographic, and isotopic constraints on the precipitation of aragonite and calcite at Shiqiang and other hot springs in Yunnan Province, China.
Download2016-01-01
Two active spring vent pools at Shiqiang (Yunnan Province, China) are characterized by a complex array of precipitates that coat the wall around the pool and the narrow ledges that surround the vent pool. These precipitates include arrays of aragonite crystals, calcite cone-dendrites, red spar...
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Modern travertine precipitation at Lýsuhóll hot springs, Snæfellnes, Iceland: implications for calcite crystal growth.
Download2017-01-01
Three thermal springs, at Lýsuhóll on Snæfellnes Peninsula on the west coast of Iceland, with vent water temperatures of 20 to 46°C are characterized by thriving microbial mats that mediate the precipitation of opal-A, Fe-rich opal-A, Fe-rich reticulate coatings, and calcite that are intermixed...
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2017-01-01
Aragonite and calcite crystals are the fundamental building blocks of calcareous thermal spring deposits. The diverse array of crystal morphologies found in these deposits, which includes monocrystals, mesocrystals, skeletal crystals, dendrites, and spherulites, are commonly precipitated under...
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2017-01-01
Many spring deposits throughout the world are characterized by spectacular deposits of calcium carbonate that are formed of various combinations of aragonite and calcite, and in very rare cases vaterite. The factors that control the precipitation of the aragonite and calcite have been the subject...