Gypsum and dolomite biomineralization in endoevaporitic microbial niche, EMISAL, Fayium, Egypt
Gypsum and dolomite biomineralization in endoevaporitic microbial niche, EMISAL, Fayium, Egypt
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DOI：
10.1007/s12665-010-0510-x
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发表时间：
2011-01-01
影响因子：
2.8
通讯作者：
Wali, Ashraf M. A.
中科院分区：
文献类型：
--
作者：
Ali-Bik, Mohamed W.;Metwally, Hussein I. M.;Wali, Ashraf M. A.
微生物岩和潜在的穹叠层石以及内蒸发白云石形式的生物石膏沉积在以微生物爆发为特征的常年盐湖盆地中。结合 XRD、XRF 和 FTIR 数据讨论了沉积环境、发生模式和显微研究（包括这些沉淀物的 SEM）。盐度梯度和风作用对石膏露头成熟度的综合影响是明显的。特征性的多色垂直石膏剖面反映了缺氧微环境的陡峭梯度，并编码了不同的季节性微生物群落。微生物特征对石膏晶体习性的直接影响是显而易见的。内蒸发自生白云石记录在亚硒酸盐层间隙的特定层位中。
Biogenic gypsum in the form of microbialite and potential domal stromatolite as well as endoevaporitic dolomite are deposited in a perennial saline basin characterized by microbial bloom. Deposition environment, mode of occurrence, and microscopic investigation including SEM of these precipitates are discussed in conjunction with XRD, XRF, and FTIR data. Combined effects of salinity gradient and the wind action on the maturity of gypsum outcrop are evident. A characteristic multi-color vertical gypsum profile reflects steep gradient of oxi-anoxic microenvironments and encodes diverse seasonal microbial communities. Direct impact of microbial signature in gypsum crystal habit is conspicuous. Endoevaporitic authigenic dolomite is recorded in specific horizons in interstices of selenite layers.