Mineral Potential Within the Eastern California Shear Zone February, 2017 Larry M. Vredenburgh U. S. Bureau of Land Management, 3801 Pegasus Dr., Bakersfield, CA 93308, [email protected]The California Desert Conservation Area: Modelling Mineral Potential A desert study program had been initiated by the Bureau of Land Management (BLM) as early as 1968, but completion of the study acquired upmost urgency when President Richard Nixon signed an executive order on February 8, 1972 requiring a program of off-road vehicle management of all federal lands (Los Angeles Times, 2 Mar 1975, p. 31). Further, each agency was given 6 months to develop and issue regulations, “to provide for administrative designation of the specific areas and trails on public lands on which the use of off-road vehicles may be permitted, and areas in which the use of off-road vehicles may not be permitted, and set a date by which such designation of all public lands shall be completed.” On November 1, 1973, the BLM published the “Record for the Interim Critical Management Program (ICMP) for Recreation Vehicle Use on the California Desert,” fulfilling the requirement of the executive order. Shortly after the completion of the ICMP the BLM published notices seeking public input for an updated ICMP (Los Angeles Times, 15 Aug 1974, p. 74). During this time (1973 -1974) BLM began hiring subject matter experts to evaluate the resources for the existing environment of the California Desert. This new effort envisioned evaluating 27 areas and preparing Resource Use Plans (Los Angeles Times 8 July 1976, p 51). The BLM estimated the planning effort would be completed in 1982 (Los Angeles Times 2 Mar 1975, p. 33). On October 21, 1976 Congress passed the Federal Land Policy and Management Act (FLPMA). This legislation was the Bureau of Land Management’s “organic act” which established the agency’s purpose and direction, it also established the 25 million acre California Desert Conservation Area (CDCA). In FLPMA Congress directed the agency to complete a land use plan for the CDCA by September 30, 1980. Congress actually funded this mandate, and perhaps even more surprisingly the plan was completed on time. BLM hired subject matter experts to assemble and lead teams to assess the resources of the CDCA. The plan elements included, cultural resources, Native American coordination, wildlife, vegetation, wilderness, wild horse and burro management, livestock grazing, recreation, mineral resources, energy production and utility corridors, and land-tenure adjustment. Jean Juilland, was hired by BLM in 1973 to evaluate Geology, Energy and Mineral (GEM) resources. He was born in Romania in 1928. He earned a diploma in Mining Technology at the Haileybury School of Mines in Canada, and completed his BSc, and MSc, at Michigan Technical University, with post-graduate studies at Stanford University. He mined and did mineral exploration in Peru, and was a mine geologist and then production planner for the underground gold mine McIntyre Porcupine Mines in Schumacher, Ontario, Canada. Also, Jean worked for Texas Instruments in Colorado. He then did exploration for Geophoto, a wholly-owned subsidiary of Texas Instruments. He was their senior geologist and assistant manager in Brisbane, Australia. He later became the company’s projects manager for mineral exploration throughout Australia. He consulted for Placer Amex, Inc. in California while doing his doctoral research on the Lights Creek Stock.
Transcript
Mineral Potential Within the Eastern California Shear Zone
February, 2017
Larry M. Vredenburgh U. S. Bureau of Land Management, 3801 Pegasus Dr., Bakersfield, CA 93308, [email protected]
The California Desert Conservation Area: Modelling Mineral Potential
A desert study program had been initiated by the Bureau of Land Management (BLM) as early as 1968, but completion of the study acquired upmost urgency when President Richard Nixon signed an executive order on February 8, 1972 requiring a program of off-road vehicle management of all federal lands (Los Angeles Times, 2 Mar 1975, p. 31). Further, each agency was given 6 months to develop and issue regulations, “to provide for administrative designation of the specific areas and trails on public lands on which the use of off-road vehicles may be permitted, and areas in which the use of off-road vehicles may not be permitted, and set a date by which such designation of all public lands shall be completed.” On November 1, 1973, the BLM published the “Record for the Interim Critical Management Program (ICMP) for Recreation Vehicle Use on the California Desert,” fulfilling the requirement of the executive order.
Shortly after the completion of the ICMP the BLM published notices seeking public input for an updated ICMP (Los Angeles Times, 15 Aug 1974, p. 74). During this time (1973 -1974) BLM began hiring subject matter experts to evaluate the resources for the existing environment of the California Desert. This new effort envisioned evaluating 27 areas and preparing Resource Use Plans (Los Angeles Times 8 July 1976, p 51). The BLM estimated the planning effort would be completed in 1982 (Los Angeles Times 2 Mar 1975, p. 33).
On October 21, 1976 Congress passed the Federal Land Policy and Management Act (FLPMA). This legislation was the Bureau of Land Management’s “organic act” which established the agency’s purpose and direction, it also established the 25 million acre California Desert Conservation Area (CDCA). In FLPMA Congress directed the agency to complete a land use plan for the CDCA by September 30, 1980. Congress actually funded this mandate, and perhaps even more surprisingly the plan was completed on time.
BLM hired subject matter experts to assemble and lead teams to assess the resources of the CDCA. The plan elements included, cultural resources, Native American coordination, wildlife, vegetation, wilderness, wild horse and burro management, livestock grazing, recreation, mineral resources, energy production and utility corridors, and land-tenure adjustment.
Jean Juilland, was hired by BLM in 1973 to evaluate Geology, Energy and Mineral (GEM) resources. He was born in Romania in 1928. He earned a diploma in Mining Technology at the Haileybury School of Mines in Canada, and completed his BSc, and MSc, at Michigan Technical University, with post-graduate studies at Stanford University. He mined and did mineral exploration in Peru, and was a mine geologist and then production planner for the underground gold mine McIntyre Porcupine Mines in Schumacher, Ontario, Canada. Also, Jean worked for Texas Instruments in Colorado. He then did exploration for Geophoto, a wholly-owned subsidiary of Texas Instruments. He was their senior geologist and assistant manager in Brisbane, Australia. He later became the company’s projects manager for mineral exploration throughout Australia. He consulted for Placer Amex, Inc. in California while doing his doctoral research on the Lights Creek Stock.
Evaluation of the mineral resources of the CDCA was a huge task. Jean approached it with some of the latest techniques – airborne geophysics, enhanced imagery, and a landscape scale drainage sediment geochemical survey.
Stream Sediment samples were collected from 1240 sites. Two samples were collected from each site; one sample was sieved, the other was sieved and panned, resulting in a heavy mineral concentrate. These samples were analyzed using semiquantitative, direct-current arc-emission spectrography.
A “Landsat Enhancement Project” was delivered August 1979 by General Electric, Space Division. Products included a lineament map, tonal anomaly map (inferred areas of hydrothermal alteration), and a regional statistical analysis of metallic mineral potential. Data used in the statistical analysis included a weighted score for lineaments, favorable lithology, and known mineral occurrences. A 10km grid cell was used.
Another contract assembled a computerized list of mineral occurrences. The U. S. Geological Survey’s Mineral Resources Data System (MRDS) hadn’t been invented yet! This data was one of the layers used in the GE statistical analysis.
Besides these high-level studies, there was an aggressive field component as well. One assignment I had was to investigate a prominent, inferred area of hydrothermal alteration as defined from Landsat imagery high in the Avawatz Range.
The minerals staff divided the CDCA into 75 separate areas and, using all the available data, wrote reports summarizing the GEM Resources in that area. However, not all of the area reports were completed before the completion of the Desert Plan.
This was all accomplished long before the personal computer, and due to technical difficulties, GIS technology, was not used. Most of the information was reduced to mylar overlays for evaluation and interpretation.
Mineral Potential Within the Eastern California Shear Zone
Today, to assemble this data requires less than an hour. The US Geological Survey has created an interactive map service with all of these data sets as well as many others https://mrdata.usgs.gov/general/map.html
Each data set has a link which will lead you to the raw data. And, if you aren’t GIS savvy, they have kmz files available to use with Google Earth.
And if that isn’t enough data, there’s more! Zoom into your area of interest and when you click on the map, a table pops up that displays the following data sets: geology, airborne geophysical surveys, estimates of undiscovered mineral resources, mine locations (MRDS), National Geochemical Database (this includes the BLM geochemical survey), global assessment of undiscovered copper resources, mine features from USGS topo maps, and a list of all references in the National Geologic Map database. All this data can easily be downloaded.
To experiment with some of these data sets I added areas of inferred hydrothermal alteration (Mars, 2013), USGS MRDS mine location, and faults. I didn’t run a geostatistical query on this data, and of course many other data sets could have been added. Just eye-balling the overlap of these themes, the following mines / areas stand out: Panamint Range, Slate Range. Avawatz Range, Dale Mining District, Eagle Mountains. Of course, the test would be to thoroughly study an area with alteration with no mines.
I would like to thank Sue Marcus, a former co-worker on the Desert Plan Staff, for sending me a copy of Jean Juilland’s obituary, “Jean Juilland SME An Appreciation by Sue Marcus.”
Bibliography
Environmental Analysis Record for the Interim Critical Management Program for Recreation Vehicle Use on the California Desert. November 1, 1973, US Department of the Interior Bureau of Land Management, California Desert Staff. 572 p. https://archive.org/details/interimcriticalm00unit
Executive Order 11644--Use of off-road vehicles on the public lands https://www.archives.gov/federal-register/codification/executive-order/11644.html
Mars, John C., 2013, Hydrothermal Alteration Maps of the Central and Southern Basin and Range Province of the United States Compiled From Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Data, US Geological Survey Open-File Report 2013-1139 https://pubs.usgs.gov/of/2013/1139/
Jean Juilland 1928-2016, Obituary http://www.legacy.com/obituaries/mercurynews/obituary.aspx?pid=181603589
Philip Fradkin, 825,000 Desert Acres May Be Closed to Off-Road Vehicle Use, Los Angeles Times 19 Sep 1973, p. 7.
Prelat, A.E., Kowalik, W.S., Lyon, R.J.P., 1979, Mineral exploration evaluation of part of the California Desert Conservation Area, based on integration of Landsat data with geological and airborne geophysical data: unpublished SLM contract no. YA -512-CT8-234.
The California Desert Conservation Area Plan, US Department of the Interior, Bureau of Land Management, Desert District, Riverside, California, 1980. https://archive.org/details/californiadesert5115unit
Vredenburgh, Larry M., 1988, Geology and Mineral Resources of the Avawatz Mountains Resource Area, San Bernardino County, California in Geology of the Death Valley Region South Coast Geological Society, Guidebook 16 pp. 305-344
