Procedencia y edad de las diamictitas del Paleozoico inferior de la cuenca de Perú-Bolivia (Gondwana occidental)

An extensive diamictite-bearing unit is present within the lower Palaeozoic siliciclastic sequence of the Central Andes. A review of its lithostratigraphy, sedimentology and biostratigraphy allows to differentiate two subunits according to their provenance and age. The correlative San Gabán Formatio...

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Detalhes bibliográficos
Autor: Díaz Martínez, Enrique
Formato: artículo
Fecha de publicación:2005
País:España
Recursos:Universidad de Huelva (UHU)
Repositorio:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:español
OAI Identifier:oai:ariasmontano.uhu.es:10272/8752
Acesso em linha:http://hdl.handle.net/10272/8752
Access Level:acceso abierto
Palavra-chave:Ordovician
Silurian
Diamictite
Bolivia
Gondwana
Descrição
Resumo:An extensive diamictite-bearing unit is present within the lower Palaeozoic siliciclastic sequence of the Central Andes. A review of its lithostratigraphy, sedimentology and biostratigraphy allows to differentiate two subunits according to their provenance and age. The correlative San Gabán Formation (Perú), Cancañiri Formation (Bolivia) and Zapla Formation (NW Argentina), of Hirnantian(?)-Llandovery age, presents evidence for resedimentation from a glaciated tectonically-active source area located to the west and south. It includes granitoid boulders, and large olistoliths of late Ordovician units. In central Bolivia, the lowermost Kirusillas Formation (early Wenlock) presents evidence for resedimentation of shallow shelf deposits from a nearby source located to the east and north. It includes olistoliths of the Sacta Limestone Member (earliest Wenlock). Only careful sedimentology and biostratigraphy may discern between the two units when both are present in the same section