Chipaque Formation

Description

Lithologies

The Chipaque Formation has a maximum thickness of 1,700 metres (5,600 ft) and is characterised by a sequence of pyritic organic shales, limestones and siltstones, with sandstone banks intercalated in the formation. The Chipaque Formation contains a high density of fauna. The formation is rich in TOC and one of the principal source rocks for oil and gas generation in the foothills of the Eastern Ranges, sourcing such fields as Cusiana, Cupiagua and many others. Chipaque also sourced the oilfields of the Llanos Orientales. In the Chitasugá-1 well, drilled between 1980 and 1981, from the sandstones of the Chipaque Formation half a million m³ of water were produced. The sandstone beds are reservoir rocks for oil in the Eastern Ranges.

Stratigraphy and depositional environment

The Chipaque Formation overlies the Une Formation and is overlain by the Guadalupe Group. The core of the Zipaquirá Anticline consists of the Chipaque Formation. The age has been estimated to be Cenomanian-Turonian. Stratigraphically, the formation is time equivalent with the Simijaca Formation. The formation has been deposited in an open to shallow marine platform setting. The deposition is represented by a maximum flooding surface and anoxic conditions.

Outcrops

The Chipaque Formation is apart from its type locality, found in the Eastern Hills of Bogotá, the Ocetá Páramo and many other locations in the Eastern Ranges. The anticlinals of the Río Blanco-Machetá, San José and Sopó-Sesquilé are composed of the Chipaque Formation.

Regional correlations

Legend

• group
• important formation
• fossiliferous formation
• minor formation
• (age in Ma)
• proximal Llanos (Medina)
• distal Llanos (Saltarin 1A well)