Microcrystalline sphalerite in resin globules suspended in Lake Kivu, East Africa

Mineralium Deposita
By: , and 

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Abstract

The origin and chemical nature of micron-sized spheres found as suspended particles in Lake Kivu are examined. It can be shown that the hollow spheres, with a wall thickness of 500 Å, consist of a complex polymeric resinous material which has little functionality, except for hydroxyl groups. The spheres arise in the process of degassing of water samples at depth. Tiny gas bubbles, about 1 micron in size, act as scavengers of dissolved resinous material. The newly created resinous membrane promotes the selective coordination of zinc dissolved in the water column. In the prevailing H2S regime, formation of sphalerite crystals in induced. The size range of the crystals, 5 to 50 Å, corresponds to 1 to 10 unit cells and suggests that the resinous membrane also acts as a template in sphalerite growth processes. The sources of the zinc and dissolved gases (CO2, CH4, H2S) are hydrothermal springs seeping from the lake bottom into the basin. Water discharge is substantial; about 100 years are required to fill the lake to its present level (ca. 550 km3 water). The average Kivu water contains 2 ppm zinc. Thus, 1 million tons of zinc are contained in Lake Kivu in the form of sphalerite.


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Publication type Article
Publication Subtype Journal Article
Title Microcrystalline sphalerite in resin globules suspended in Lake Kivu, East Africa
Series title Mineralium Deposita
DOI 10.1007/BF00206891
Volume 7
Issue 1
Year Published 1972
Language English
Publisher Springer
Description 12 p.
First page 1
Last page 12
Country Democratic Republic of Congo, Rwanda
Other Geospatial Lake Kivu
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