Calcite precipitation and Recrystallization fabrics—their significance in Jurassic Limestones of Europe
作者:
PeterJ. Davies,
期刊:
Journal of the Geological Society of Australia
(Taylor Available online 1971)
卷期:
Volume 18,
issue 3
页码: 279-292
ISSN:0016-7614
年代: 1971
DOI:10.1080/00167617108728767
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Many fabrics in Corallian (Upper Jurassic) carbonates in England, France and Switzerland are bigenetic, forming by solution/precipitation and recrystallization processes. Early precipitated cements are non‐ferroan, whereas those formed later are decidedly ferroan. Mossbauer spectroscopy has shown that the iron in the carbonates is largely divalent, substituting for calcium in the calcite lattice. The cements may be subdivided into those forming in an oxidizing environment, and those forming in a reducing environment. Fabric evidence indicates that a solution period separates the two cement phases. The diagenetic history is linked with the sedimentation pattern. Thus, under progressive build up of sediments into shallow‐water or supratidal conditions, the first‐phase cement probably precipitated from non‐marine, partially oxygenated vadose water. Subsequent subsidence and sedimentation resulted in the depression of partially cemented sediments into zones within the sedimentary pile conducive first to pyrite precipitation, and then to ferroan calcite precipitation. Fabrics can therefore be used to interpret the diagenetic environment of regressive sedimentary associations.
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