Sedimentary iron sulfide minerals play a key role in maintaining the oxygenation of Earth’s atmosphere over geological timescales; they also record critical geochemical information that can be used to reconstruct paleo-environments. On modern Earth, sedimentary iron sulfide mineral formation takes places in low-temperature environments and requires the production of free sulfide by sulfate-redu...

Early geodynamic processes modeled the surface of the Earth, providing suitable environments and energy sources for the development of life. Studying the ancient biogeochemical cycles is thus a valuable way to understand the physicochemical conditions of the early environments, such as the redox state of the primitive oceans and the atmosphere. To investigate early biogeochemistries, the measur...

23 24 Large rounded pyrite grains (>1 mm), commonly referred to as ‘buckshot’ pyrites, are a characteristic feature of 25 the auriferous conglomerates (reefs) in the Witwatersrand and Ventersdorp supergroups. Detailed petrographic 26 analyses of the reefs indicated that the vast majority of the buckshot pyrites are of reworked sedimentary origin, 27 i.e., that the pyrite originally formed in th...

27 Supercritical flow phenomena are fairly common in modern sedimentary environments, yet their 28 recognition and analysis remain difficult in the stratigraphic record. This fact is commonly 29 ascribed to the poor preservation potential of deposits from high-energy supercritical flows. 30 However, the number of flume datasets on supercritical flow dynamics and sedimentary 31 structures is ver...

Bacteria are the most abundant forms of life we know on our planet that can be able to survive in a variety of habitats, from hot to cold springs, from soils to deep sedimentary rocks, in radioactive wastes and in living organisms. It has been estimated (Whitman et al., 1998; Lipp et al., 2008) that the prokaryote number is 3.5 5.0·1030 and although global subseafloor sedimentary microbial abun...

Near surface groundwater contamination is a widespread problem. The potential for contamination of deep aquifers in such areas depends on the vertical hydraulic gradient as well as the extent and location of interconnection between the upper and lower aquifers. In alluvial~ sedimentary environments, the geologic units are typically weakly connected lenses or layers of high or low conductivity w...

Detection of sedimentary cycles is difficult in fine-grained or homogenous sediments but is a prerequisite for the interpretation of depositional environments. Here we use a new autocorrelation analysis to detect cycles in a homogenous sediment core, E602, from the northern shelf of the South China Sea. Autocorrelation coefficients were calculated for different mean grain sizes at various depth...