Unusual sedimentary geodes filled by gold-bearing hematite laths

Unusual sedimentary geodes filled by gold-bearing hematite laths

Unusual mineralized and silicified carbonate-rich geodes were found hosted in Lower Triassic red mudstones in Central Spain. From their borders to their centres, the geodes display (a) a millimetric carbonate crust, (b) a quartz rim, (c) massive dolomite, (d) gold-bearing iron-rich infills (hematite laths and goethite with up to 7000 ppm of gold) and (e) calcite cements that sometimes seal the ...

Unusual geodes ('bone cysts') in rheumatoid arthritis.

BIOOXIDATION OF MOUTEH REFRACTORY GOLD-BEARING CONCENTRATE BY AN ADAPTED THIOBACILLUS FERROOXIDANS

The Mouteh refractory pyrite concentrates at pulp densities of 1.5%, 3%, 4.5% and 6% were treated, using Thiobacillus ferrooxidans DSM 581 and the same bacteria adapted on the Mouteh pyritic concentrate. Compared with a non-adapted culture, use of an adapted inoculum of T. ferrooxidans increased bioleaching rate of iron by a factor of 1.940, 2.011, 1.859 and 1.559 for pulp densities 1.5%, 3%, 4...

Gold Bearing Conglomerates in some Molasse Basins of Iran

This article lists a number of geological data on the conditions of formation of some major gold deposits in the conglomerates of the Earth's crust. We analyze the metallogenic, tectonic, stratigraphic and other factors controlling the formation of gold-bearing conglomerates in certain fields, such as the Witwatersrand (S. Africa) and Darwaz (Tajikistan). The following tectonic factors play the...

A New Unusual Ice-induced Sedimentary Structure: the Silt Mushroom

Upon channel bars or point bars within the lows of the Yellow River, a new sedimentary structure, named 'silt mushroom', has been observed. The process of their formation is interpreted to be via the ice process. The name, the silt mushroom comes from their figurative form. This is because they look somewhat similar to mushroom's in size and shape; being in the range of 1 to 10 cm in diameter, ...