Evolving source areas for upper Cretaceous-lower Tertiary marine to continental strata of central Colombia

Conference · Wed Mar 01 00:00:00 EST 1989 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:5993127

Ressetar, R; Segall, M P; Laverde, F E; Allen, R B

Late Cretaceous marine conditions in the Upper Magdalena Valley (UMV) and the Sabana of Colombia ended with deposition of the regressive Guadalupe (Campanian-Maastrichtian) and Guaduas (Maastrichtian-Paleocene) Formations, followed by terrestrial deposition of the Gualanday Group (Eocene). X-ray diffraction, SEM, and thin-section analyses of samples from the southern UMV and the Sabana reveal compositional trends related to different depositional conditions and to evolving source terrains. The upper Guadalupe Formation of the southern UMV is mineralogically distinct from the overlying units, containing high average concentrations of illite/smectite (40%) and clay-size quartz (20%) with little discrete illite. The data indicate that after deposition of the Guadalupe Formation from a volcanic/metamorphic source, the sediment source changed or was completely cut off. Chemical weathering was enhanced during deposition of the Guaduas Formation in the UMV, but marine sedimentation, reflected in the uniform composition, continued in the Sabana. Anomalously high illite/smectite concentrations and overall variability in the Gualanday Group indicate a return to a volcanic source with deposition in an alluvial fan/fluvial environment.

• Research Organization: Univ. of South Carolina, Columbia (USA)
• OSTI ID: 5993127
• Report Number(s): CONF-890404-
• Journal Information: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States), Vol. 73:3; Conference: AAPG annual convention with DPA/EMD Divisions and SEPM, San Antonio, TX, USA, 23-26 Apr 1989
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
COLOMBIA
STRATIGRAPHY
ALLUVIAL DEPOSITS
CRETACEOUS PERIOD
EOCENE EPOCH
GEOLOGIC FORMATIONS
ILLITE
QUARTZ
VOLCANIC ROCKS
X-RAY DIFFRACTION
CENOZOIC ERA
CHALCOGENIDES
CLAYS
COHERENT SCATTERING
DIFFRACTION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
IGNEOUS ROCKS
LATIN AMERICA
MESOZOIC ERA
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
ROCKS
SCATTERING
SILICON COMPOUNDS
SILICON OXIDES
SOUTH AMERICA
TERTIARY PERIOD
020200* - Petroleum- Reserves
Geology
& Exploration