“白云石（岩）问题”与湖相白云岩研究

 近30年来,微生物白云石模式推动“白云石（岩）问题”前进了一大步,大量的实验和实例证明微生物（硫酸盐还原菌、产甲烷古菌、中度嗜盐有氧细菌等）的代谢活动对于促进白云石低温沉淀起了关键作用。微生物白云石特殊的微结构、微形貌和稳定同位素特征是其主要识别标志。然而,该模式在微生物成岩规模、诱导机制、是否存在纳米细菌化石以及现代微生物白云石成因模式能否用来解释古代白云石的成因等方面仍存在较大争议。我国古代湖相白云岩因其时空分布广、成因机制多样等特点可为“白云石问题”的研究提供良好的条件。

"Dolomite Problem" and Research of Ancient Lacustrine Dolostones

In the past thirty years,microbial dolomite model provides a new insight into long standing “Dolomite Problem”. Many experiments and cases demonstrated that the metabolic activities of microorganisms (sulfate reducing bacteria, methanogenic Archaea, and moderately halophilic aerobic bacteria, etc.) played a key role in mediating the dolomite low temperature precipitation. The characteristic microtexture, micromorphology and specific carbonate isotopes are the major distinguishing remarks of the microbial dolomite. However,there have still controversies on the scale of microbial dolomite, its mediation mechanism, whether there exist putative "nanobacteria" fossils, and whether the modern microbial dolomite model can be reliable criteria to ancient analogues. Ancient lascustrine dolostones widespread in China which show a diversity of mechanisms, offer good opputinities to better understand these intensive issues in comparison with the modern counterparts.