Source terrains and diagenetic imprints of Cretaceous marine rocks of the Cordillera Oriental, Colombia

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

OSTI ID:6066767

Segall, M P; Allen, R B ^[1]; Rubiano, J; Sarmiento, L ^[2]

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1. Univ. of South Carolina, Columbia (United States)
2. Instituto Colombiano de Petroleos, Bucaramanga (Colombia)

Cretaceous marine rocks of the western Cordillera Oriental of Colombia are exposed in stratigraphic sections which reveal multiple source terrains and variable diagenetic histories that were imposed by later thrusting XRD and petrographic analyses indicate that earliest Cretaceous rocks were derived from a nearly plutonic source (Triassic-Jurassic Ibague Batholith of the Cordillera Central) which provided feldspathic lithic fragments and clay-sized illite. High smectite concentrations in the overlying Hauterivian-Barremian strata reflect contemporaneous volcanism, possibly in the Cordillera Central. This signal decreased upsection to the upper Aptian, where detrital clays (kaolinite, chlorite, feldspar, amphibole) indicate a shift to a cratonic source, probably the Guayana Shield. Cratonic detrital input continues into the Turonian-Coniacian and is accompanies by high concentrations of smectite representing another period of volcanic activity. Later tectonic activity divided the area into two regions, each with unique diagenetic signatures. Three primary clastic sources are inferred for the section east of the thrust belt, however, the mineral assemblage is masked by later diagenesis. Sediments within the thrust belt show greater variability in the relative abundance of mineral assemblages and more poorly crystallized illite than occurs to the east of the thrust section. The preservation of much of the original mineralogic components within the thrust section indicates that these sediments have experienced only limited diagenetic overprinting as a result of a relatively short burial history. These contrasting signatures have important implications for hydrocarbon maturation within Cretaceous source rocks in a structurally complex region.

• OSTI ID: 6066767
• Report Number(s): CONF-930306-; CODEN: AABUD2
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:2; Conference: International congress of the American Association of Petroleum Geologists (AAPG), Caracas (Venezuela), 14-17 Mar 1993; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
COLOMBIA
GEOLOGIC HISTORY
HYDROCARBONS
MATURATION
SOURCE ROCKS
STRATIFICATION
CLAYS
CRETACEOUS PERIOD
DIAGENESIS
ILLITE
MINERALS
MOUNTAINS
PETROGENESIS
SEA BED
SEDIMENTS
SMECTITE
VOLCANISM
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGY
LATIN AMERICA
MESOZOIC ERA
ORGANIC COMPOUNDS
PETROLOGY
SILICATE MINERALS
SOUTH AMERICA
020200* - Petroleum- Reserves
Geology
& Exploration