Geologic Map of Southern Venezuela: A multinational team led by Jeff Wynn conducted a mineral resource appraisal and produced a new kind of geologic map of the Precambrian craton in the jungle of southern Venezuela. (A CD-ROM of this and related products is available.)
Phosphate Geophysics: Geophysical methods were used to map phosphate resources, and hidden cavities (karsts) that complicate economic resource development, in the Al-jalamid area on the Iraqi border of northern Saudi Arabia, all as part of a larger mine feasibility project.
The Wabar Meteorite Impact: Results of a mapping expedition to an iron-nickel meteorite impact site in the Empty Quarter of Saudi Arabia suggest a very recent event, comparable in kinetic energy release to the Hiroshima bomb (with the late Eugene M. Shoemaker).
Landfill and Toxic Waste Mapping: Using magnetic and electromagnetic methods to find the long-lost Ft. Chaffee (Arkansas) World-War-II-era German P.O.W. camp landfill, and to map the toxic chemical plume emanating from it.
Couer d'Alene River Experiments: Experiments carried out using a modified form of the induced polarization (IP) method and an underwater version of ground-penetrating radar (GPR) to locate and identify toxic mine wastes dumped over the last century into the Couer d'Alene River and upper Couer d'Alene Lake.
Mapping Groundwater to 400 Meters Depth Using an Aircraft: The 1997-1999 Upper San Pedro River Airborne Geophysical Surveys: A 60-channel airborne ElectroMagnetic (EM) and magnetic survey was flown in two parts over and east of Fort Huachuca, Arizona. These surveys were carried out at the request of the U.S. Army NEPA Coordinator at the Fort Huachuca Garrison, and mapped water over about 1,000 square kilometers to depths of up to 400 meters. The surveys were carried out in an attempt to understand the aquifer and buried structures that may control the groundwater movement lying between the Huachuca Mountains near Sierra Vista, and the Mule Hills south of Tombstone, Arizona, which together bound the San Pedro River north of the Mexican border. At issue is the need to precisely map the groundwater in 3-D in order to model the hydrology, and thereby determine the impact of the nearby Fort Huachuca and the neighboring city of Sierra Vista on the water flowing in the nearby San Pedro National Riparian Conservation Area.
Offshore Exploration Geophysics Technologies: Using the induced polarization method to map and evaluate titanium (in the form of ilmenite) and other heavy minerals including gold and platinum in offshore paleoplacer deposits, and to conduct sub-seafloor mineral exploration from a moving vessel. Potential additional applications to beach-reclamation sands, buried UXO (UneXploded Ordnance), and dumped urban waste on the seafloor are also discussed. Recent experiments suggest this system can find buried wrecks and fragments of wrecks hidden beneath several meters of younger sediment. An unconsolidated sediments physical properties laboratory was established in Reston, Virginia, and used to analyze samples (including cores) from the deep ocean floor.
In August 2000 a Cooperative Research and Development Agreement ("CRADA") was signed with Williamson and Associates of Seattle, Washington, to commercialize this new technology. A shallow-water system has been built, and a new, deep-water version of the system will be built during 2003-2004, designed for trans-oceanic cable-route mapping. In June, 2001, two patents were awarded for the marine induced polarization technology.
Duncan-Zarembo Islands (Alaska) Geophysical Signature Profiles: Magnetic field measurements, used along with magnetic susceptibility and VLF-EM resistivity sampling, were used to develop a geophysical-signatures database of mapped units in the southern Tongass National Forest area of southeastern Alaska, centered around the Duncan Canal and Zarembo Island region southwest of Wrangell and northwest of Ketchikan. The objective was to provide control data for analysis of the 1997 Stikine Airborne Geophysical Survey, and to provide characteristic geophysical signatures to allow geologists to identify the Triassic terranes in the region that could potentially host more Volcanogenic Massive Sulfide ("VMS") deposits like the huge Greens Creek VMS deposit on Admiralty Island.
Geophysical character of volcanic massive sulfide deposits and their geologic setting, Ketchikan Mining District, Alaska: This abstract, released for the Alaska Miners Association meeting in November 2000, describes progress in remapping the southeastern quadrant of Prince of Wales Island using airborne geophysical methods, ground-sampling for physical properties, and focused geological mapping. The objective is to identify areas permissive of VMS deposits, but in a geologic terrain different from Admiralty and and Duncan-Zarembo Islands.
Craig-Dixon-Entrance Geophysics: This reports the availability of a new CD-ROM releasing the data, gridded files, images of magnetic and gravity fields superimposed on local topography, and some limited 2.5-D models and interpretations for aeromagnetic and gravity surveys conducted from 1983 through 1991 in the Craig and Dixon Entrance quadrangles, located in the Tongass National Forest, at the extreme southern tip of the Alexander Archipelago west of Ketchikan, Alaska [the CD-ROM is U.S. Geological Survey Digital Data Series DDS-56].
Prince William Forest Acid-Mine-Drainage Geophysics Study: This open-file report describes the successful use of a multi-frequency ElectroMagnetic ("EM") system to map acid-mine drainage from an abandoned sulfide mine located about 50 kilometers south of Washington, DC. The GEM-300 system we used allows us to generate a six-layer 3-D image of the conductor from the surface down to about 10 meters depth over a 200 meter x 150 meter test site.
Electrical geophysical methods: Applied subsurface imaging methods including resistivity, induced polarization (IP), spectral IP, ground and airborne electromagnetics (also called EM and AEM, including VLF), magnetotellurics(MT), controlled-source audio-frequency magnetotellurics (CSAMT).
Magnetic and gravity methods: Acquisition of potential-field data (gravity and magnetics), as well as processing to derive so-called daughter-products, model buried geologic structures, etc.
Remote sensing and airborne multichannel spectrometer imaging: Image-acquisition using Visible, infrared (IR), thermal IR , side-Looking airborne radar, etc., from satellite (LANDSAT and ASTER) and aircraft platforms.
Volcano-seismic monitoring: Seismic networks, GPS-based geodetic networks, and gravity level-lines used to monitor volcanic unrest around the cities of Makkah and Madinah, Saudi Arabia.
Borehole geophysics: Electrical, nuclear, sonic, mechanical, magnetic, and other techniques used in well-bores in the exploration for phosphate, and in setting screens to develop a deep production water well in Saudi Arabia.
Mineral Resource Assessments: Monte Carlo simulation to evaluate gold and other undiscovered resources in the United States and Venezuela.
Marine geophysics: Using electrical geophysical and other methods to map sub-seafloor sediments for minerals, urban waste, and buried man-made objects (including ancient wrecks and unexploded ordnance) beneath the sediments of the Atlantic Continental Shelf and Gulf of Mexico.
Geologic mapping: Eleven different 1:1,000,000 and 1:500,000-scale geologic and 3-dimensional tectonic maps of Southern Venezuela (published) and Mexico (in progress).
Hydro-Geophysics: Using airborne magnetic methods to map depth to crystalline basement, and airborne multi-channel time-domain electromagnetic ("AEM") and Audio-Frequency Magnetotellurics ("AMT") systems to map groundwater in three dimensions in the arid southwestern United States and northern Mexico.
Wynn has served as an International Technical Advisor to:
Jordan (1979): Jeff Wynn supervised the planning and contracting for a US$2.5M combined airborne electromagnetic("AEM") and helicopter-borne ("HEM") survey, along with a LANDSAT image analysis, in the search for geothermal and mineral resources of the western half of Jordan..
Thailand (1980-1981): Gravity and VLF-EM resistivity methods were used to map potash deposits by locating hidden salt diapirs in breached anticlines on the Khorat Plateau of northeastern Thailand.
Venezuela (1987-1990): Ground and airborne geophysics, regional geologic mapping, mineral exploration (chiefly for gold and diamonds), and a complete mineral resource assessment were carried out on the jungle-covered southern half of Venezuela. (Jeff Wynn served here also as USGS Mission Chief , or "Jefe del Grupo Asesor," as the first author of the 1:1,000,000-scale geologic map of the southern half of Venezuela, and also as a diplomat, a formal member of the Economic Section of the United States Embassy in Caracas).
Saudi Arabia (1976-1979, 1991-1995): Ground geophysical surveys, airborne multichannel visible-to-thermal-infra-red spectral imaging, and borehole logging were conducted to assist mineral exploration (primarily gold and phosphate) efforts. In addition, geodetic GPS surveys, gravity level-lines, and telemetered seismic networks were used to monitor the historically active Harrat Rahat volcanic field southeast of Madinah al-Munawarrah. A portable digital seismic network was also set up to monitor unusual seismic activity in the region around Makkah. (Jeff Wynn served here in diplomatic status as Deputy Chief of Mission for Scientific Affairs in the USGS Jeddah, Saudi Arabia Office, as well as Chief Geophysicist, Chief of the Remote Sensing Section, and Chief of the Madinah-Makkah Volcano-Seismic Monitoring Project).
Mauritania (1996): Jeff Wynn participated in the development of a geologic mapping, geophysical surveying, and hydrologic modeling plan to strengthen the resource base of this West African nation.
U. S. Geological Survey