Petroleum source rock potential of Mesozoic condensed section deposits in southwestern Alabama

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

OSTI ID:7271654

Mancini, E A; Tew, B H; Mink, R M ^[1]

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1. Univ. of Alabama, Tuscaloosa (United States)

Because condensed section deposits in carbonates and siliclastics are generally fine-grained lithologies often containing relatively high concentrations of organic matter, these sediments have the potential to be petroleum source rocks if buried under conditions favorable for hydrocarbon generation. In the Mesozoic deposits of southwestern Alabama, only the Upper Jurassic Smackover carbonate mudstones of the condensed section of the LZAGC-4.1 cycle have realized their potential as hydrocarbon source rocks. These carbonate mudstones contain organic carbon concentrations of algal and amorphous kerogen of up to 1.7% and have thermal alteration indices of 2- to 3+. The Upper Cretaceous Tuscaloosa marine claystones of the condensed section of the UZAGC-2.5 cycle are rich (up to 2.9%) in herbaceous and amorphous organic matter but have not been subjected to burial conditions favorable for hydrocarbon generation. The Jurassic Pine Hill/Norphlet black shales of the condensed section of the LZAGC-3.1 cycle and the Upper Jurassic Haynesville carbonate mudstones of the condensed section of the LZAGC-4.2 cycle are low (0.1%) in organic carbon. Although condensed sections within depositional sequences should have the highest source rock potential, specific environmental, preservational, and/or burial history conditions within a particular basin will dictate whether or not the potential is realized as evidenced by the condensed sections of the Mesozoic depositional sequences in southwestern Alabama. Therefore, petroleum geologists can use sequence stratigraphy to identify potential source rocks; however, only through geochemical analyses can the quality of these potential source rocks be determined.

• OSTI ID: 7271654
• 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

02 PETROLEUM
58 GEOSCIENCES
ALABAMA
PETROLEUM DEPOSITS
SOURCE ROCKS
GEOCHEMISTRY
CARBON COMPOUNDS
CRETACEOUS PERIOD
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
JURASSIC PERIOD
KEROGEN
MATURATION
PETROLEUM GEOLOGY
QUANTITY RATIO
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMISTRY
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
MATERIALS
MATTER
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
ORGANIC MATTER
RESOURCES
USA
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences