High-frequency carbonate/siliciclastic reciprocal sedimentation within the Upper San Andres depositional sequence (Permian, Guadalupian), Last Chance Canyon, Guadalupe Mountains, New Mexico

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6637795

Sonnenfeld, M D ^[1]

---

1. Colorado School of Mines, Golden, CO (USA)

The upper San Andres Formation and Cherry Canyon Sandstone Tongue in Last Chance Canyon form a third-order depositional sequence comprising at least 12 smaller scale, time-bounded depositional units. The intertidal through toe-of-slope facies associations, volumetric proportions of carbonate/siliciclastic sedimentation, and depositional topography change progressively throughout the sequence. These variations reflect the controls that produce the landward-stepping, vertically stacked, and seaward-stepping arrangements of units constituting the sequence. In Last Chance Canyon many of the small-scale depositional units have stratal geometries and carbonate/siliciclastic relationships that are analogous to third-order sequences. The oldest depositional unit is a point-sourced turbidite lobe that onlaps the underlying sequence boundary. Carbonate-rich slope sandstones form the next two units, which also onlap the sequence boundary. These three landward-stepping to vertically stacked units compose the transgressive systems tract (TST). Units within the TST record a progressive decrease in sedimentation rate, depositional energy, and siliciclastic content that reflects the sequence-scale transition from toe-of-slope siliciclastic turbidites to an increasingly carbonate-dominated ramp. Within each of the two youngest units, a basal sandstone hemicycle is overlain by a mounded fusulinid-rich carbonate hemicycle. The maximum flooding surface caps the TST and is overlain by the most carbonate-rich interval of the sequence. From basal to upper slope, the facies in this unit are laminated mudstones and wackestones, crinoid-bryozoan bafflestone bioherms, brachiopod-sponge reefs, and fusulinid mounds. Seaward-stepping units compose the middle highstand systems tract (HST).

• OSTI ID: 6637795
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBONATE ROCKS
DEPOSITION
FEDERAL REGION VI
FOSSILS
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGY
NEW MEXICO
NORTH AMERICA
PALEOZOIC ERA
PERMIAN PERIOD
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
STRATIGRAPHY
USA