Microorganisms and their biomineralization processes are widespread in almost every environment on earth. In this work, Streptomyces luteogriseus DHS C014, a dominant lithophilous actinobacteria isolated from microbial mats on limestone rocks, was used to investigate its potential biomineralization to allow a better understanding of bacterial contributions to carbonate mineralization in nature....

Hydrothermal venting and the formation of carbonate chimneys in the Lost City hydrothermal field (LCHF) are driven predominantly by serpentinization reactions and cooling of mantle rocks, resulting in a highly reducing, high-pH environment with abundant dissolved hydrogen and methane. Phylogenetic and terminal restriction fragment length polymorphism analyses of 16S rRNA genes in fluids and car...

Well exposed Famennian, mainly carbonate rocks of the Bahram Formation in the vicinity of Bagher Abad village, Central Iran,yielded chondrichthyan teeth some sarcopterygii and actinopterygii teeth and fragments. Three different genera were recognizedamong the chondrichthyan teeth represented by: Phoebodus turnerae, Ph. spp., Deihim mansureae (M2, M3), Stethacanthus sp..Acanthodian and sarcopter...

It is widely accepted that the lithospheric mantle under the North China craton (NCC) has undergone comprehensive refertilization due to input from surrounding subducted slabs. However, the possible contribution from the Paleo-Asian oceanic slab to the north is poorly constrained, largely because of the lack of convincing evidence for the existence of this slab under the NCC. We report here car...

Abstract Most of the world's Zn and Pb is extracted from sediment-hosted Zn-Pb deposits. The deposits hosted in carbonate rocks are hypothesized to form by mixing acidic metal-bearing brines with reduced sulfur-bearing fluids while dissolving sedimentary carbonate. To test role this process, we conducted hydrothermal experiments simulating ore formation reacting ± Ba–bearing H2S SO42– produced ...

Owing to its diagenetic instability, aragonite is rare in the geological record and almost entirely absent from pre-carboniferous sedimentary rocks. The former presence of this mineral in older deposits has to be inferred from petrographic, chemical or isotopic proxies. Crystals of aragonite that formed around 4563 million years ago occur in carbonaceous chondrite meteorites, showing that under...

dalichai formation at the rey-abad section (northeast shahroud) along the principal road of the mayamey-jajarm has a thickness of 166 meters .in this section, middle to upper jurassic carbonate rocks are well exposed and is typically composed of massive to medium-bedded limestones with thin shale interbeds. in the studied area and most places of this region, the lower boundary of dalichai forma...

An unusual richness of biogeochemical events is recorded in Neoproterozoic– Cambrian strata of the Death Valley region, California, United States. Eight negative carbon isotope (d13C) excursions are found in carbonate units between 1.08 Ga and the Precambrian/Cambrian boundary; four of these excursions occur in carbonates that contain textural features similar to those found globally in postgla...