Microfacies analysis of the Leonardian-Guadalupian lower member of the San Andres Formation in the southern Sacremento Mountains, Otero County, New Mexico

Conference · Wed Apr 01 00:00:00 EST 1992 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7201755

Whitman, C; Clemons, R E ^[1]

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1. New Mexico State Univ., Las Cruces (United States)

The Rio Bonito Member of the San Andres Formation records a transgression of the northwestern shelf during the late Leonardian. Late Leonardian to Guadalupian marine carbonates exposed in the Sacramento Mountains relate a marked change from equatorial tidal flat rocks of the middle Leonardian Yeso Formation. These rocks were deposited during a worldwide sea level lowstand. The Yeso-San Andres contact, previously thought to be a gradational boundary, is here interpreted as a flooding surface resulting from the eustatic sea level rise after the lowstand. Inundation of the northwestern shelf led to deposition of the thick Andres Formation marine limestone sequence within a shallow-lagoon or shelf setting. Depositional environments are predominantly subtidal and intertidal. Microfacies include packstones of comminuted bioclasts of normal saline affinities redistributed by light currents. These shoal upward at times to Dasycladacean algal grainstones interpreted as tidal bars prograding across the lagoon or shelf. More restricted wackestones and laminated mudstones occur at the base of the section and indicate a transition from tidal flat to submerged shelf. Aggradation of sediment into the intertidal zone may have occurred cyclically during San Andres deposition. One such cycle is present over the interval exposed in the Sacramento Mountains. Intertidal rocks resemble tidal flat deposits of dolostone, carbonate mudstones, and a thin tongue of quartzarenite interpeted to be Glorieta Sandstone. These rocks were previously attributed to interginguing of the Yeso with the San Andres.

• OSTI ID: 7201755
• Report Number(s): CONF-9204139-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 76:4; Conference: American Association of Petroleum Geologists (AAPG) Southwest section meeting, Midland, TX (United States), 21-24 Apr 1992; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
02 PETROLEUM
03 NATURAL GAS
CARBONATE ROCKS
PETROLOGY
PERMIAN BASIN
GEOLOGIC HISTORY
STRATIGRAPHY
DEPOSITION
GEOLOGIC FORMATIONS
LITHOLOGY
NEW MEXICO
DEVELOPED COUNTRIES
FEDERAL REGION VI
GEOLOGY
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
USA
580000* - Geosciences
020200 - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration