Boletin de Geología
versão impressa ISSN 0120-0283
The stratigraphic record in EEB begins with an upper Paleozoic basal siliciclastic sequence (Farallones Group, Devonian - Carboniferous), unconformably overlain by basal Cretaceous formations (Batá to the east, Santa Rosa - Ubalá - Chivor to the west o the Quetame Massif). The Cretaceous marine ingression took place in a tectonically active basin since Triassic and Jurassic. This tectonic setting last until the end of earliest Cretaceous giving place to a thick sedimentary sequence made of the aforementioned basal units and the Lutitas de Macanal, Las Juntas, Fómeque and Une formations. Paleozoic basement highs normal fault bounded, restrict the Cretaceous sedimentation in the EEB zone, this is evidence especially for the basal Cretaceous units (Berriasian). In this way, to the east of Montecristo Anticline (overlaying Farallones Group) we found conglomerates (Batá Formation), instead to the west sedimentation was mainly lodolithic (Santa Rosa Formation, new litostratigraphic unit). Toward Ubalá, overlaying Paleozoic basement (Farallones Anticline) rest a calcareous -Terrigenous set (Ubalá Formation new litostratigraphic unit). In Chivor - Malacara area we found evaporitic sets with calcareous rocks (Chivor Formation, new litostratigraphic unit) overlaying Santa Rosa Formation. In Valanginian times the sea regionally drown the area of EEB and give rise to marine offshore conditions (Lutitas de Macanal Formation) with episodic events of gravity flows (El Fígaro - Los Cedros members). During Hauterivian to Albian times the accumulation of a sandy - muddy sediments in tidal flats or deltaic systems give rise the record of Las Juntas -Une formations. Finally in Barremian early Albian times there is a siliciclastic - calcareous record of marine offshore environments (Fómeque Formation).
Palavras-chave : Eastern Emerald Belt (EEB); Cretaceous; Colombia.