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Research about New Mexico

Source-linked reports with geographic coverage including New Mexico.

At least 505 records · Page 28Linked to original sources
USGS1991

Organic matter variations in transgressive and regressive shales

Organic matter in the Upper Cretaceous Mancos Shale adjacent to the Tocito Sandstone in the San Juan Basin of New Mexico was characterized using organic petrology and organic geochemistry. Differences in the organic matter found in these regressive and transgressive offshore marine sediments have been documented and assessed within a sequence stratigraphic framework. The regressive Lower Mancos Shale below the Tocito Sandstone contains abundant well preserved phytoclasts and correspondingly low hydrogen indices. Total organic carbon values for the regressive shale are low. Sediments from the transgressive systems tract (Tocito Sandstone and overlying Upper Mancos Shale) contain less terrestrially derived organic matter, more amorphous non-structured protistoclasts, higher hydrogen indices and more total organic carbon. Advanced stages of degradation are characteristic of the phytoclasts found in the transgressive shale. Amorphous material in the transgressive shale fluoresces strongly while that found in the regressive shale is typically non-fluorescent. Data from pyrolysis-gas chromatography confirm these observations. These differences are apparently related to the contrasting depositional styles that were active on the shelf during regression and subsequent transgression. It is suggested that data from organic petrology and organic geochemistry provide greater resolution in sedimentologic and stratigraphic interpretations, particularly when working with basinward, fine-grained sediments. Petroleum source potential for the regressive Lower Mancos Shale below the Tocito Sandstone is poor. Based on abundant fluorescent amorphous material, high hydrogen indices, and high total organic carbon, the transgressive Upper Mancos Shale above the Tocito Sandstone possesses excellent source potential. This suggests that appreciable source potential can be found in offshore, fine-grained sediments of the transgressive systems tract below the condensed section and associated downlap surface. Organic petrology can be used to accurately predict petroleum source potential. The addition of simple fluorescence microscopy greatly enhances this predictive ability because non-generative amorphous material is generally non-fluorescent. Organic petrology must also be used to properly evaluate the utility of T max from programmed pyrolysis as a thermal maturity indicator. Organic matter dominated by autochthonous amorphous protistoclasts exhibits lower T max values than that which is composed of mostly phytoclasts.

New Mexico↗
USGS1991

Coal resources of the Fruitland Formation in part of the Ute Mountain Ute Indian Reservation, San Juan County, New Mexico

The coal-bearing Upper Cretaceous Fruitland Formation occupies an area of about 14 square miles in the extreme southeast corner of the Ute Mountain Ute Indian Reservation in San Juan County, New Mexico. In this area, the Fruitland Formation contains an estimated 252 million short tons of coal in beds that range from 1.2 to 14 feet thick. About 100 million short tons of coal occur under less than 500 feet of overburden in the Ute Canyon, Upper Main, and Main coal beds. These three coal beds reach a cumulative coal thickness of about 18 feet in a stratigraphic interval that averages about 120 feet thick in the prospecting permit area, which is located in the extreme southwestern part of the study area. The southwestern part of the study area is probably best suited for surface mining, although steep dips may reduce minability locally. A major haul road that was recently constructed across the eastern half of the study area greatly improves the potential for surface mining. Core sample analyses indicate that the apparent rank of the Ute Canyon, Upper Main, and Main coal beds is high-volatile C bituminous. Average heat-of-combustion on an as-received basis is 10,250 British thermal units per pound, average ash content is 15.5 percent, and average sulfur content is 1.0 percent.

New Mexico↗
USGS1991

Water resources data, New Mexico, water year 1990

This annual hydrologic data report of New Mexico is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and water quality provide the hydrologic information needed by Federal, State, and local. agencies and the private sector for developing and managing our Nation's land and water resources. Hydrologic data for New Mexico are contained in this volume. This report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey who collected, compiled, analyzed; verified, and organiZed the data, and who typed, edited, and assembled the report. The authors had primary responsibility for aSSUring that the information contained herein is accurate, complete, and adheres to Geological Survey policy and established guidelines. The following individuals contributed significantly to the completion of the report: Harriet R. Allen Mary Montano Cynthia J. Shattuck K.M. Lange, M.F. Ortiz, and L.A. Watson processed the text of the report, and H.M. Grossman drafted the illustrations.

New Mexico↗
USGS1990

Brunhes chron excursion/polarity episode recorded during the late pleistocene, Albuquerque Volcanoes, New Mexico, USA

All basaltic lava flows of the Albuquerque Volcanoes (lat.: 35.2°N, long.: 253.2°E), Albuquerque-Belen Basin, New Mexico, record a short excursion/polarity episode. K-Ar isotopic age determinations (weighted average: 155 ± 47 ka) and evaluation of soil profiles on flow surfaces suggest the late Pleistocene ( circa between 250 and 80 ka) as the time of extrusion. Results from 63 sites in a minimum of eight flows yield a mean direction of D = 101.1°, I = -36.1°, α 95 = 1.2° (α 1 95 = 0.7, α 2 95 = 1.2), k = 2219 ( N = 8 flows) and a corresponding virtual geomagnetic pole position (VGP) of 354.1°E, 20.2°S, dp = 0.8°, dm = 1.4° ( A 1 95 = 0.5, A 2 95 = 1.4), and VGP angular standard deviation (ASD) = 1.8°. The unusual magnetization in flows of the Albuquerque Volcanoes is carried by fine-grained [single-domain (SD) and/or pseudo-single-domain (PSD)] low-Ti magnetite and is apparently not a function of complex sub-solidus alteration of magnetic phases. Underlying baked soils contain a relatively low coercivity magnetization with directions comprising two groups. One is roughly antipodal to the lava remanence; the other intermediate between the lava remanence and present field direction. Because all flows yield statistically indistinguishable directions, a field directional path clearly cannot be defined. At the precision level of our age determinations, the Albuquerque feature may correlate with other short polarity episodes or excursions of late Pleistocene age (e.g., Blake or Jamaica). Though characteristically limited in directional morphology, well-dated polarity episodes (i.e. sub-chrons) and excursions recorded in volcanic rocks may provide information on the frequency of significant dynamo instabilities.

New Mexico↗