Paleogene depositional patterns in the Magdalena Valley and Cordillera Oriental: Implications for deformational phases

Conference · Mon Feb 01 04:00:00 EST 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6063788

Ressetar, R; Allen, R B; Alfonso, C A ^[1]; Sarmiento, L ^[2]; Ramirez, C; Laverde, F ^[3]

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1. Univ. of South Carolina, Columbia (United States)
2. Instituto Colombiano de Petroleos, Bucaramanga (Colombia)
3. Hocol-Shell, Cartagena (Colombia)

The Paleogene rocks of the Magdalena Valley and the Cordillera Oriental of Colombia represent the synorogenic sedimentary fill of the ancestral Andean foreland basin. Although detailed correlation of the Paleogene is hampered by poor biostratigraphic control, recent field studies document variations between the Upper and Middle Magdalena Valleys in vertical facies succession and paleocurrent direction, suggesting independent depositional systems separated by the Girardot fold belt. In the northern Upper Magdalena Valley, the Paleogene Gualanday Group lies unconformably to paraconformably on marine Upper Cretaceous and Paleocene rocks. Lower and upperconglomeratic units in the Gualanday Group grade eastward into finer grained fluvial sandstones in the western Cordillera Oriental. North of the Girardot belt, conglomerates occur only in the lower part of the Paleogene and grade northeastward into fluvial sandstones. These unconformably overlie rocks as old as Neocomian in a series of en echelon structures on the west flank of the Cordillera Oriental. The structural trends and thickness of the Cretaceous here suggest inversion of the marine depocenter prior to Paleogene deposition. Previous reports of early Paleogene uplift of the Quetame Massif south of Bogota indicate that similar processes acted elsewhere in the Cordillera Oriental. These studies show that the Cordillera Oriental underwent at least one phase of uplift prior to the main inversion in the Neogene.

• OSTI ID: 6063788
• Report Number(s): CONF-930306--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 77:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
CENOZOIC ERA
COLOMBIA
CONGLOMERATES
CRETACEOUS PERIOD
DEFORMATION
DEPOSITION
DEVELOPING COUNTRIES
DIMENSIONS
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
GEOMORPHOLOGY
LATIN AMERICA
MESOZOIC ERA
ORIENTATION
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SOUTH AMERICA
TERTIARY PERIOD
THICKNESS
VALLEYS
VARIATIONS