skip to main content

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

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 resemblemore » 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.« less
Authors:
;  [1]
  1. (New Mexico State Univ., Las Cruces (United States))
Publication Date:
OSTI Identifier:
7201755
Report Number(s):
CONF-9204139--
Journal ID: ISSN 0149-1423; CODEN: AABUD
Resource Type:
Conference
Resource Relation:
Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States); Journal Volume: 76:4; Conference: American Association of Petroleum Geologists (AAPG) Southwest section meeting, Midland, TX (United States), 21-24 Apr 1992
Country of Publication:
United States
Language:
English
Subject:
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