Sedimentology of the distal fan and lake deposits of the Tianshui- Qinan Basin (Central China): evidences against a possible eolian origin

In this paper we analyze two sections within the Tianshui-Qinan Basin, a closed basin in Central China. The deposits are Miocene and Pliocene in age and in recent times they have been considered as loess. The preliminary sedimentological study indicates a closed lacustrine basin, with a very flat to...

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Detalles Bibliográficos
Autores: Alonso Zarza, Ana María, Li, J., Zhao, Z., Song, C. H., Zhang, J., Wang, X., Zhang, Y.
Tipo de recurso: artículo
Fecha de publicación:2006
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:español
OAI Identifier:oai:docta.ucm.es:20.500.14352/52438
Acceso en línea:https://hdl.handle.net/20.500.14352/52438
Access Level:acceso abierto
Palabra clave:552.5
Tertiary
Central China
Tianshui-Qinan Basin
Alluvial fan
Lake deposits
Calcretes
Petrología
Descripción
Sumario:In this paper we analyze two sections within the Tianshui-Qinan Basin, a closed basin in Central China. The deposits are Miocene and Pliocene in age and in recent times they have been considered as loess. The preliminary sedimentological study indicates a closed lacustrine basin, with a very flat topography in the inner parts. Periodical desiccation and subaerial exposure periods of both mudflats and shallow lakes caused important reworking of the sediments. The lake margins were ramp-like with different energy levels. Low energy lake margins are represented by marls, intraclastic and palus- trine limestones, whereas higher energetic levels are indicated by rippled sands and silts.