Subaqueous salts (including natron, epsomite, bloedite, mirabilite) are precipitated during late summer, autumn and winter in several hypersaline lakes, some by evaporative concentration, others by brine cooling and freeze-out. Microbial mats form extensively along many littoral zones and around springs laminates are preserved in some cores.Įfflorescent salt crusts cover saline mudflats around most lakes and playas. Springs and ephemeral seepages are locally present. Sedimentary structures are disrupted by carbonate precipitation and displacive salt crystallization. Some mudflats are carbonate-dominated others are predominantly siliciclastic with only highly soluble interstitial salts forming. The amount of carbonate formed varies with groundwater composition. Mudflats are primarily a zone of extensive interstitial carbonate precipitation from shallow groundwaters, including abundant magnesite and hydromagnesite. ![]() Fluvial sediments are of little significance. ![]() Most basins comprise three main subenvironments-hillslope, mudflat (saline and dry) and lake (ephemeral or perennial). The region is characterized by extremely cold winters and short hot summers.ĭense coniferous forest mantles much of the plateau and surrounds most of the lakes. On the Cariboo Plateau, where they are most abundant, the saline lakes are small, shallow, and occupy depressions within glacial and glacio-fluvial deposits. The lake waters have highly variable compositions, with Na-CO 3-Cl, Na-CO 3-(SO 4)-Cl, Mg-Na-SO 4 and Na-Mg-SO 4, the dominant types of brine. There are several hundred saline lakes in Interior British Columbia, including muddy siliciclastic playas, saline playas, perennial lakes (including meromictic sulphate lakes), and ephemeral lakes, some with permanent salts.
0 Comments
Leave a Reply. |