A Study of Regional Geophysical Data in the Holbrook Area, Arizona

An analysis of the available geophysical data in the Holbrook basin area of north central Arizona in Coconino, Navajo and Apache Counties has been made. This study has been supported by a contract with the Arizona Oil and Gas Conservation Commission, John Bannister, executive secretary, and the Four Corners Regional Commission. The primary objectives of the analysis were to determine: (1) thicknesses and lithology of sedimentary column overlying Precambrian basement; (2) structural configuration of basement surface, faults in basement and sedimentary rocks; and (3) anomalous conditions within the sedimentary rocks potentially favorable for entrapment of hydrocarbons.Originally published as OGCC Report of Investigation RI-2 in 1972Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]

A Geophysical and Geological Investigation of Potentially Favorable Areas for Petroleum Exploration in Southeastern Arizona

The objective of this study has been to determine areas potentially favorable for oil and gas exploration in southeastern Arizona. Surface geological investigations in the mountain ranges indicate that a thick sequence of marine sedimentary Paleozoic and Mesozoic (Cretaceous) rocks was deposited in the Pedregosa basin in southeastern Cochise County and adjacent shelf areas. According to Wengerd (1962), Kottlowski (1971), Greenwood (1969), and Greenwood and Kottlowski {1974), these marine strata deposited in this basin are similar in many aspects to those in petroleum-productive areas in southeast New Mexico and west Texas. They contain organic-rich basin facies of rocks that were probable sources for oil and gas. The margins of the Pedregosa basin offer structural, stratigraphic, unconformity, and paleogeomorphic traps. However, such adverse factors as the wide thickness variance of Cenozoic valley fill (100 feet or less to almost 12,000 feet), very little information as to the absence or presence of potentially petroleum-productive undeformed Paleozoic and Mesozoic rocks beneath Cenozoic rocks in the valleys, and extensive evidence in the mountains that the area has had an extremely complex geologic history, have discouraged exploration in the past.Originally published in 1974 as OGCC Report of Investigation RI-3.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]

Complete Residual Bouguer Gravity Anomaly Maps

Complete residual Bouguer Gravity Anomaly maps of Arizona: map scale 1:250,000Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]

Evaluation and combined geophysical interpretations of NURE and related geoscience data in the Van Horn, Pecos, Marfa, Fort Stockton, Presidido, and Emory Peak quadrangles, Texas. Volume 1. Final report

This report (two volumes) is the culmination of a two-year study of the six Trans-Pecos Texas quadrangles (Van Horn, Pecos, Marfa, Fort Stockton, Presidio, and Emory Park) surveyed as part of the National Uranium Resource Evaluation (NURE) program. Volume I contains a discussion of the aeromagnetic, gravity and geochemical data, their processing, and their analysis. The geologic history and setting of the Trans-Pecos are discussed along with the uranium potential of the region. Uranium anomalies and occurrences characteristic of numerous different NURE classes are present in the study area, and information is presented on 33 drill holes into these targets. Volume II is a folio of maps reduced to a scale of 1:500,000. Geologic maps for each of the six quadrangles are included and the geophysical maps have been prepared to be overlays for the goelogic maps. In addition to the geologic maps, residual aeromagnetic anomaly, complete Bouguer gravity anomaly, flight line index, gravity station index, and anomaly interpretative maps were prepared for each quadrangle. A large suite of digitally processed maps of gravity and aeromagnetic data were prepared and are included in Volume II

Exploration for hot dry rock geothermal resources in the Midcontinent USA. Hot dry rock conceptual models for exploration, HDR test site investigations, and the Illinois Deep Drill Hole Project. Volume 2

Three potential sources of HDR, each covering approximately a 2/sup 0/ x 2/sup 0/ area, were identified and subjected to preliminary evaluation with ad hoc exploration strategies. In the Mississippi Embayment test site, lateral thermal conductivity variations and subcrustal heat sources may be involved in producing abnormally high subsurface temperatures. Studies indicate that enhanced temperatures are associated primarily with basement rift features where vertical displacement of aquifers and faults cause the upward migration of hot waters leading to anomalously high, local, upper crustal temperatures. The Western Nebraska test site is a potential low temperature HDR source also related, at least in part, to groundwater movement. There appear to be much more widespread possibilities for similar HDR sites in the Great Plains area. The Southeast Michigan test site was selected for study because of the possible presence of radiogenic plutons overlain by a thickened sedimentary blanket. There is no direct information on the presence of abnormally high temperatures in this area, but the study does show that a combination of gravity and magnetic anomaly mapping with regional geological information derived from sparse drill holes in the Phanerozoic rocks is useful on a widespread basis for focusing on local areas for detailed evaluation