Recovery of prokaryotic body fossils from methane seep carbonates such as those of the Cretaceous Tepee Buttes of Colorado serves as a model for sampling in future astrobiological missions. The fossils, found primarily at the interface between paragenetic fabrics, suggest a sharp physicochemical gradient. Evidence of these microbial fossils occurs at a variety of scales. In the field, microbial...

carbonates are among the most common soil constituents in arid and semiarid zones. they exhibit many significant differences in their chemical and mineralogical, suite, origin, physical and micromorphological properties and consequently in their activities in soil. the differences cause different properties of calcareous soils. six profiles of aridisols and inceptisols with carbonate accumulati...

The Avanah Formation (Middle Eocene) was studied in the Haibat sultan section at Bina Bawi Anticline, Northeast of Erbil city within Iraqi Kurdistan region. field observation indicated that formation occurs as Carbonate interbeds lower and middle parts Gercus Formation, which consists mainly light yellowish to creamy color, well-bedded, marly, dolomitic limestone with some intercalations sandst...

The Great Bank of Guizhou (GBG) is an isolated Late Permian to Late Triassic carbonate platform in the Nanpanjiang Basin of Guizhou Province, southwest China. A faulted syncline exposes a cross section of the platform margin, including a well-preserved Anisian (earliest Middle Triassic) reef complex approximately 1 km wide and 800 meters thick. Geochronologic constraints from associated basin-m...

A recent field-intensive program in Shark Bay, Western Australia provides new multi-scale perspectives on the world's most extensive modern stromatolite system. Mapping revealed a unique geographic distribution of morphologically distinct stromatolite structures, many of them previously undocumented. These distinctive structures combined with characteristic shelf physiography define eight 'Stro...

The lithographic limestone of La Pedrera de Meià (LPM) in south-Central Pyrenees (NE Spain) is considered one the best preserved lacustrine-coastal successions Early Cretaceous Europe, hosting a taxonomically diverse record Barremian biota. While this Konservat-Lagerstätte has been extensively surveyed for paleontological purposes, little known about paleoenvironmental and depositional conditio...

The dendrolites composed of light gray massive micrite limestone occur at the top Cambrian Zhangxia Formation in Houziyu Section, Zibo, Shandong Province. Because it is very difficult to study genesis microbial rocks through “the function diagenesis filter,” this paper analyzes its genetic mechanism by characterizing sedimentary fabric and formation environment great significance carbonate depo...

Marine cyanobacterial mats were cultured on coastal sediments (Nivå Bay, Øresund, Denmark) for over three years in a closed system. Carbonate particles formed in two different modes in the mat: (i) through precipitation of submicrometer-sized grains of Mg calcite within the mucilage near the base of living cyanobacterial layers, and (ii) through precipitation of a variety of mixed Mg calcite/ar...