USGS Science⌕ Search

Geology topics

Maryla Deszcz-Pan

Publications and source records attributed to Maryla Deszcz-Pan.

4 recordsLinked to original sources
USGS2023

Resistivity imaging over porphyry copper systems in the Red Mountain district, southwest Colorado, USA

The Red Mountain district in southwestern Colorado produced base and precious metals hosted in breccia pipes and vein structures related to an extensive lithocap that overlies pervasive quartz-sericite-pyrite alteration. A helicopter-borne time-domain electromagnetic survey flown over the district yielded resistivity values that range from tens to thousand or more ohm-m, with lesser resistivity values in the lithocap and greater resistivity values in the rocks with propylitic alteration. A 60 m-thick, low resistivity zone subparallel to topography characterizes the magmatic-hydrothermal breccia pipes. A broad zone of low resistivity that may envelope epithermal deposits spans multiple flight lines and occurs beneath rocks with argillic alteration. A 50 m-thick low resistivity zone occurs beneath quartz-sericite-pyrite alteration and may indicate porphyry deposit at depth.

Colorado↗
USGS2011

Helicopter electromagnetic and magnetic geophysical survey data, Hunton anticline, south-central Oklahoma

This report is a digital data release for multiple geophysical surveys conducted in the Hunton anticline area of south-central Oklahoma. The helicopter electromagnetic and magnetic surveys were flown on March 16–17, 2007, in four areas of the Hunton anticline in south-central Oklahoma. The objective of this project is to improve the understanding of the geohydrologic framework of the Arbuckle-Simpson aquifer. The electromagnetic sensor for the helicopter electromagnetic survey consisted of six different transmitter-receiver orientations that measured the earth's electrical response at six distinct frequencies from approximately 500 Hertz to approximately 115,000 Hertz. The electromagnetic measurements were converted to electrical resistivity values, which were gridded and plotted on georeferenced maps. The map from each frequency represents a different depth of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow groundwater. The four areas selected for the helicopter electromagnetic study, blocks A–D, have different geologic and hydrologic settings. Geophysical and hydrologic information from U.S. Geological Survey studies are being used by modelers and resource managers to develop groundwater resource plans for the Arbuckle-Simpson aquifer.

Oklahoma↗
USGS2000

High resolution, low altitude aeromagnetic and electromagnetic survey of Mt Rainier

In October 1996, the USGS conducted a high resolution airborne magnetic and electromagnetic survey in order to discern through-going sections of exposed altered rocks and those obscured beneath snow, vegetation and surficial unaltered rocks. Hydrothermally altered rocks weaken volcanic edifices, creating the potential for catastrophic sector collapses and ensuing formation of destructive volcanic debris flows. This data once compiled and interpreted, will be used to examine the geophysical properties of the Mt. Rainier volcano, and help assist the USGS in its Volcanic Hazards Program and at its Cascades Volcano Observatory. Aeromagnetic and electromagnetic data provide a means for seeing through surficial layers and have been tools for delineating structures within volcanoes. However, previously acquired geophysical data were not useful for small-scale geologic mapping. In this report, we present the new aeromagnetic and electromagnetic data, compare results from previously obtained, low-resolution aeromagnetic data with new data collected at a low-altitude and closely spaced flightlines, and provide information on potential problems with using high-resolution data.

Washington↗