This paper presents results of biogeochemical investigation the Holocene organic-rich sapropelic sediments Lake Dukhovoe situated not far from Baikal. The main source organic matter in is phytoplankton, which serves as a barrier where elements are accumulated water and then buried bottom sediments. Microorganisms (e.g., bacteria, micromycete actinomycetes) play significant role decomposition fo...

The bulk magnetic mineral record from Lake Ohrid, spanning the past 637 kyr, reflects large-scale shifts in hydrological conditions, and, superimposed, a strong signal of environmental conditions on glacial–interglacial and millennial timescales. A shift in the formation of early diagenetic ferrimagnetic iron sulfides to siderites is observed around 320 ka. This change is probably associated wi...

The chemical and physical characteristics of realgar (an arsenic sulfide mineral that occurs in several crystalline forms) in the presence of Acidithiobacillus ferrooxidans BY-3 were investigated in this work. Grains of the mineral were incubated for 10, 20, and 30 days with A. ferrooxidans cultured in 9K medium at 30 °C and at 150 rpm agitation. Abiotic control experiments were conducted in id...

The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicates, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 x 10 most ...

Abstract Unusual hydrothermal native As-sulfide ± Ag arsenide antimonide sulfosalt ore shoots and their co-genetic sulfide-fluorite-barite-quartz host veins, which are common in the region whole Central Europe, were investigated at three localities Schwarzwald, SW Germany, to understand physico-chemical processes governing change from a normal (= common) an exceptional shoot regime. Based on fl...

Recent studies have shown that nanoparticles exist in environmental water but the formation, characteristics and fate of such particles remain incompletely understood. We show here that surface water obtained from various sources (ocean, hot springs, and soil) produces mineralo-organic particles that gradually increase in size and number during incubation. Seawater produces mineralo-organic par...

Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions,...

Little is known about the importance and/or mechanisms of biological mineral oxidation in sediments, partially due to the difficulties associated with culturing mineral-oxidizing microbes. We demonstrate that electrochemical enrichment is a feasible approach for isolation of microbes capable of gaining electrons from insoluble minerals. To this end we constructed sediment microcosms and incubat...

jian cu deposit is hosted by surian volcano-sedimentary complex of permo-triassic age on the eastern edge of the sanandaj-sirjan metamorphic zone at a distance of 195 km from shiraz, southwestern iran. the complex consists mainly of metabasalt, chlorite-quartz schist, chlorite-muscovite schist, mica schist and graphite schist. pyrite is the most important sulfide and chalcopyrite is the major c...