Provenance of Gondwana sandstones of the Parana basin, Brazil

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5529706

Dutta, P K ^[1]; Santos, P R ^[2]

---

1. Indiana State Univ., Terre Haute (United States)
2. Inst. de Geosciences, Sao Paulo (Brazil)

Gondwana sedimentation in the Parana basin was initiated as a result of epeirogenic uplift of the Brazilian craton during Upper Carboniferous glaciation. Uninterrupted sedimentation continued until the end of the Permian and resulted in deposition of three marine/marginal-marine/continental facies. A second episode of cratonic uplift in Triassic time was responsible for deposition of two additional continental facies. Based on mineralogical composition of the arenites, five petrofacies have been identified that correspond to five lithofacies. A cyclical compositional trend of the petrofacies, in chronological order from the base, have the following QFL values: 87:9:4 (petrofacies 1) in the glaciomarine facies {yields} 97:3:0 (Petrofacies 2) in the marginal marine Coal Measures {yields} 90:9:1 (Petrofacies 3) in the continental sandstone-red/green shale facies {yields} 76:23:1 (Petrofacies 4) in the fluvial sand {yields} and 93:7:0 (Petrofacies 5) in the eolian sand. Compositional maturity of Petrofacies 2 relative to Petrofacies 1 is attributed to the chemical decay of unstable grains in a humid climate that prevailed during coal formation. The relative immaturity and presence of fresh feldspars in Petrofacies 1 is presumably due to the presence of some granitic source rock and lack of chemical weathering in the glacial climate. Petrofacies 3 swings back to immaturity possibly due to the decline of the humid climate as indicated by the absence of coal and the beginning of a global arid trend. Petrofacies 4 represents the most immature unit of the entire succession and is related to aridity and another tectonic uplift of the craton that resulted in unroofing of some more granitic rock. Maturity of Petrofacies V relative to the underlying fluvial sand is possibly due to mechanical destruction of feldspars through eolian processes.

• OSTI ID: 5529706
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
BRAZIL
SEDIMENTARY BASINS
SANDSTONES
MINERALOGY
GEOLOGIC HISTORY
STRATIGRAPHY
FELDSPARS
PETROLOGY
PLATE TECTONICS
SEDIMENTATION
DEVELOPING COUNTRIES
GEOLOGIC STRUCTURES
GEOLOGY
LATIN AMERICA
MINERALS
ROCKS
SEDIMENTARY ROCKS
SILICATE MINERALS
SOUTH AMERICA
TECTONICS
580000* - Geosciences