Here we use laser Raman microprobe analyses of fluid inclusions trapped in halites from these Permian deposits to argue for the existence of highly acidic (pH <1) lakes and ground waters. They were deposited in non-marine saline lakes, pans and mud-flats2, settings that are typically assumed to have been alkaline. read more read lessĪbstract: Evaporites hosted by red beds (red shales and sandstones), some 275–265 million years old, extend over a large area of the North American mid-continent1. Abstract: Naturally acid saline systems with pH values between 17 and 4 are common on the Yilgarn Craton of southern Western Australia A combination of physical and chemical processes here yield a previously undescribed type of modern sedimentary environment Flooding, evapoconcentration, desiccation, and eolian transport at the surface, as well as influx of acid saline groundwaters, strongly influence these lakes Halite, gypsum, kaolinite, and iron oxides precipitate from acid hypersaline lake waters Shallow acid saline groundwaters affect the sediments of the lakes and associated mudflats, sandflats, channels, and dunes by precipitating early diagenetic halite, gypsum, iron oxides, clays, jarosite, and alunite These modern environments would likely yield a rock record composed mostly of bedded red siliciclastic and reworked gypsum sand, alternating with less common beds of bottom-growth gypsum and halite, with alteration by early diagenetic features diagnostic of acid saline waters This documentation of sedimentary processes and products of modern acid saline environments is an addition to the comparative sedimentology knowledge base and an expansion of the traditional models for classifying brines Implications include better interpretations of terrestrial redbeds and lithified martian strata, improved acid remediation methods, new models for the formation and occlusion of pores, and the new setting for finding previously undescribed extremophiles.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |