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Title: Abo Formation alluvial facies and Associated Basin Fill, Sacramento Mountains, New Mexico

Abstract

Outcrops of the Abo Formation (Wolfcampian to early Leonardian age) in the Sacramento Mountains of south-central New Mexico record the evolution of a dry alluvial fan system as it was deposited off the pedernal uplift into the Orogrande basin. The location and orientation of present-day outcrops allow us to observe an inferred east-to-west transverse facies tract consisting of: (1) proximal alluvial fans (lower Abo), which are contiguous in places with underlying Laborcita Formation fan-deltaic sediments; (2) medial anastomosed streams (middle Abo); and (3) distal low-gradient mud-dominated flood basins characterized by either distributary streams (upper Abo) or clastic tidal flats (Lee Ranch Tongue of the Abo) with associated marine carbonates (Pendejo Tongue of the Hueco Formation). Tectonism in the Pedernal highlands, which climaxed during the Late Pennsylvanian, apparently continued well into the Wolfcampian in this region, as evidenced by a major basal Abo unconformity and distinct stacked megasequences of lower Abo alluvial fan lithofacies. However, by the middle Abo, tectonic activity had quiesced and the uplift began eroding and retreating to the north and east. By the late Abo, a pediment surface had formed that was subsequently onlapped by upper Abo and eventually Yeso Formation sediments.

Authors:
Publication Date:
Research Org.:
Yates Petroleum Corp., Artesia, NM
OSTI Identifier:
6968642
Alternate Identifier(s):
OSTI ID: 6968642
Report Number(s):
CONF-8604186-
Journal ID: CODEN: AAPGB
Resource Type:
Conference
Resource Relation:
Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States); Journal Volume: 70:3; Conference: American Association of Petroleum Geologists Southwest Section convention, Ruidoso, NM, USA, 27 Apr 1986
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; NEW MEXICO; RESERVOIR ROCK; GEOLOGIC HISTORY; GEOLOGIC FORMATIONS; SEDIMENTARY BASINS; TECTONICS; FEDERAL REGION VI; GEOLOGIC STRUCTURES; NORTH AMERICA; USA 020200* -- Petroleum-- Reserves, Geology, & Exploration

Citation Formats

Speer, S.W. Abo Formation alluvial facies and Associated Basin Fill, Sacramento Mountains, New Mexico. United States: N. p., 1986. Web.
Speer, S.W. Abo Formation alluvial facies and Associated Basin Fill, Sacramento Mountains, New Mexico. United States.
Speer, S.W. Sat . "Abo Formation alluvial facies and Associated Basin Fill, Sacramento Mountains, New Mexico". United States. doi:.
@article{osti_6968642,
title = {Abo Formation alluvial facies and Associated Basin Fill, Sacramento Mountains, New Mexico},
author = {Speer, S.W.},
abstractNote = {Outcrops of the Abo Formation (Wolfcampian to early Leonardian age) in the Sacramento Mountains of south-central New Mexico record the evolution of a dry alluvial fan system as it was deposited off the pedernal uplift into the Orogrande basin. The location and orientation of present-day outcrops allow us to observe an inferred east-to-west transverse facies tract consisting of: (1) proximal alluvial fans (lower Abo), which are contiguous in places with underlying Laborcita Formation fan-deltaic sediments; (2) medial anastomosed streams (middle Abo); and (3) distal low-gradient mud-dominated flood basins characterized by either distributary streams (upper Abo) or clastic tidal flats (Lee Ranch Tongue of the Abo) with associated marine carbonates (Pendejo Tongue of the Hueco Formation). Tectonism in the Pedernal highlands, which climaxed during the Late Pennsylvanian, apparently continued well into the Wolfcampian in this region, as evidenced by a major basal Abo unconformity and distinct stacked megasequences of lower Abo alluvial fan lithofacies. However, by the middle Abo, tectonic activity had quiesced and the uplift began eroding and retreating to the north and east. By the late Abo, a pediment surface had formed that was subsequently onlapped by upper Abo and eventually Yeso Formation sediments.},
doi = {},
journal = {Am. Assoc. Pet. Geol., Bull.; (United States)},
number = ,
volume = 70:3,
place = {United States},
year = {Sat Mar 01 00:00:00 EST 1986},
month = {Sat Mar 01 00:00:00 EST 1986}
}

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  • Outcrop exposures of the Laborcita Formation (Wolfcampian) reveal an active depositional environment with abrupt lateral and vertical changes between fan-deltaic and carbonate sediments. The siliciclastic source area was to the east, in the Pedernal uplift. Fan-delta lobe shifting was important in producing the cyclic nature of deposition. Away from the area affected by the fan-deltas, deposits are increasingly calcareous. Shales are the predominant lithology in the Laborcita Formation, due to the abundance of carbonate-inhibiting terrigenous matter, especially in restricted areas. A few digitate stromatolites and Archeolithophyllum sp. mounds indicate subaerial exposure. Toward the edge of the narrow shelf, large phylloid-algalmore » buildups (20 m or 65 ft thick) occur. An exposure in Coyote Canyon, near the northern end of the Laborcita exposure, shows an onlapping sequence of several mounds. This mound zone was terminated when muds and fine to medium-grained terrigenous sands migrated in and inhibited growth of the carbonate-producing organisms. The terrigenous sediments were in turn overlain by grainstones exhibiting long, low-angle (15/sup 0/) cross-bedding, which dips landward (southeast). Individual grainstone beds are thin (0.5-1.5 m or 1.6-5 ft), extend along strike laterally for about 2.5 mi (4 km), and are composed largely of bioclastic carbonate grains (not oolitically coated) with 5% quart grains. Direction of migration was southwest to northeast. Gradual emergence is recorded by the Laborcita Formation. With continual progradation of terrigenous deposits, interrupted by marine incursions resulting in deposition of shallow-water carbonated deposits, the transitional Laborcita Formation was ultimately overlain by the terrigenous Abo Formation.« less
  • Depositional environments that change dramatically over short lateral distances are represented by exposures of the Laborcita Formation. A siliclastic source area lay to the east and southeast, in the Pedernal Mountains. To the west, a shallow marine sea filled the orogrande basin. Alternating cycles of marine and nonmarine sedimentation resulted from fan-delta lobe shifting and eustatic sea level movements. In clear-water areas not affected by fan-deltaic sedimentation, deposits become increasingly calcareous. Various carbonate facies resulted from organisms adapting to changing environmental conditions. Mud-cracked algal mats, digitate algal stromatolites, and small phylloid red algal mounds and rhodoliths indicate deposition in shallow-watermore » subtidal to supratidal settings. Large buildups (20 m thick) of phylloid green algae associated with abundant submarine cement occurred in a position near the edge of the narrow shelf. Widespread skeletal detritus beds overlie and extend hundreds of meters away from the massive buildups. Influx of terrigenous mud and silt in advance of a prograding fan-delta system terminated growth of the buildups. The next transgression is represented by a carbonate grainstone exhibiting characteristics of shallow-water marine, storm-dominated shelf bars. The shelf bars migrated in a northwest-southeast direction.« less
  • Petrographic studies of outcrop and drill core samples in the Westwater Canyon Member of the Morrison Formation along the southern and western margins of the San Juan basin reveal a close spatial relationship among altered (iron-leached) detrital magnetite and ilmenite (FeTi oxides), depositional facies in the overlying Brushy Basin Member, and distribution of primary uranium deposits. Iron leaching of FeTi oxides resulted from passage of solutions containing soluble organic material; concentrations of this organic material are the sites of the primary uranium ore bodies. Along the southern and western parts of the basin, FeTi oxides typically have been leached inmore » the upper Westwater Member, but are unaltered in the lower Westwater; however, locally, leaching occurred throughout the Westwater. This zone of leaching systematically thins northward to zero, where unleached FeTi oxides occur throughout the Westwater. Regional patterns of alteration of FeTi oxides correspond to regional facies distribution in the overlying Brushy Basin Member. Extensive FeTi oxide leaching characterizes the Westwater beneath the smectite-rich mud-flat facies of the Brushy Basin, whereas negligible leaching characterizes the Westwater beneath the zeolite-rich playa facies of the Brushy Basin. This correspondence between facies and alteration patterns suggests that solutions responsible for solubilization of organic material, which in turn leached FeTi oxides in the Westwater, originated from the mud-flat facies of the Brushy Basin. Organic material that precipitated form these solutions concentrated uranium to form primary uranium ore bodies; therefore, distribution of the Brushy Basin mud-flat facies may define, and restrict, distribution of primary ore bodies in the Westwater.« less
  • Late Paleozoic collision of Laurussia and Gondwanaland resulted in regionally consistent sedimentation patterns that record two modes of lithospheric deformation in Arizona and New Mexico. Discrete intraforeland depocenters, the Orogrande and Pedregosa basins, formed in middle to late Pennsylvanian time (late Atokan-Virgilian). A regional unconformity is present at the base of the Permian system. Early Wolfcampian depositional thicknesses largely mimic and accentuate those of the Pennsylvanian, but later Wolfcampian rocks onlap intraforeland uplifts. Depositional systems paralleled the larger collision suture; a marine basin in southern New Mexico and Arizona graded northward to widespread redbeds deposited by south-flowing rivers. Intraforeland highsmore » in northern Arizona and New Mexico were blanketed by sediment in late Wolfcampian time, whereas uplifts in southern New Mexico were covered in the Leonardian. Pennsylvanian basins formed during intraforeland wrench faulting that resulted from initial collision of marginal salients on one or both of the continental masses. The Wolfcampian basin formed through a combination of renewed wrenching and flexural subsidence during final suturing of the two supercontinents.« less
  • Red and orange beds in carbonate sequences are commonly attributed to syngenetic oxidation due to prolonged subaerial exposure. In this study, the authors demonstrate that stratigraphically continuous ferruginous beds do not necessarily represent early oxidation. In the Upper Pennsylvanian Holder Formation in the Sacramento Mountains, New Mexico, successive carbonate cycles and biohermal mounds are draped by 30-60 cm thick ferruginous-stained beds. The staining has been interpreted as recording syngenetic oxidation and precipitation of iron oxides during times of low sea level. Their work demonstrates that the iron oxides and hydroxides formed due to modern weathering of ferroan dolomite. Paleomagnetic analysismore » of the ferruginous beds by stepwise thermal demagnetization gives a mean declination of 10/sup 0/E and inclination of +61/sup 0/ (k = 330, ..cap alpha../sub 95/ = 1.9), which corresponds to the modern field direction for the study location. Preliminary investigation of samples from the biohermal mounds indicate a complex magnetization with unresolved, although apparently secondary components of magnetization. Maximum blocking temperatures less than 110/sup 0/C for the major component and other rock magnetic studies suggest the remnants is carried by goethite. Petrographic analysis indicates that goethite is present associated with calcitized dolomite in the samples. The amount of ferruginous stain and total magnetic intensity of the samples also decrease away from the exposed edge of the carbonate beds. These results suggest that the remnants in the ferruginous beds is a chemical remnant magnetization that formed as a result of modern, not syngenetic, diagenetic processes.« less