Pisoids from the Lower Carboniferous Llanelly Formation of South Wales contain both algal and fascicular-optic calcite laminae. The latter are here interpreted as a replacement product of aragonite and display characteristic calcitization textures. The original aragonite laminae formed in a hypersaline setting and are compared with Recent coniatoid deposits. The pisoids also show evidence of having grown periodically in a near normal marine setting as well as showing evidence of early solution probably by meteoric waters. The pisoids grew in a schizohaline lagoon formed as the initial phase of a marine incursion, during a period of fluctuating peritidal and arid floodplain deposition. The schizohalinity resulted from seasonal effects in a climate with a marked dry season.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.