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Sandstone copper assessment of the Chu-Sarysu Basin, Central Kazakhstan

Scientific Investigations Report 2010-5090-E

Prepared in cooperation with the Centre for Russian and Central EurAsian Mineral Studies Natural History Museum, London, United Kingdom, and Mining and Economic Consulting, Ltd., Almaty, Kazakhstan. This report is Chapter E of SIR 2010-5090. For other chapters see SIR 2010-5090 .
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Abstract

Mineral resource assessments represent a synthesis of available information to estimate the location, quality, and quantity of undiscovered mineral resources in the upper part of the Earth's crust. This report presents a probabilistic mineral resource assessment of undiscovered sandstone copper deposits within the late Paleozoic Chu-Sarysu Basin in central Kazakhstan by the U.S. Geological Survey as a contribution to a global assessment of mineral resources. The purposes of this study are to: (1) provide a database of known sandstone copper deposits and significant prospects in this area, (2) delineate permissive areas (tracts) for undiscovered sandstone copper deposits within 2 km of the surface at a scale of 1:1,000,000, (3) estimate numbers of undiscovered deposits within these permissive tracts at several levels of confidence, and (4) provide probabilistic estimates of amounts of copper (Cu), silver (Ag), and mineralized rock that could be contained in undiscovered deposits within each tract. The assessment uses the three-part form of mineral resource assessment based on mineral deposit models (Singer, 1993; Singer and Menzie, 2010). Delineation of permissive tracts for resources is based on the distribution of a Carboniferous oxidized nonmarine clastic (red bed) stratigraphic sequence that lies between overlying Permian and underlying Devonian evaporite-bearing sequences. Subsurface information on the extent and depth of this red bed sequence and structural features that divide the basin into sub-basins was used to define four permissive tracts. Structure contour maps, mineral occurrence databases, drill hole lithologic logs, geophysical maps, soil geochemical maps, locations of producing gas fields, and evidence for former gas accumulations were considered in conjunction with descriptive deposit models and grade and tonnage models to guide the assessment team's estimates of undiscovered deposits in each tract. The four permissive tracts are structural sub-basins of the Chu-Sarysu Basin and range in size from 750 to 65,000 km2. Probabilistic estimates of numbers of undiscovered sandstone copper deposits were made for the four tracts by a group of experts. Using these probabilistic estimates, Monte Carlo simulation was used to estimate the amount of metal contained within each tract. The results of the simulation serve as the basis for estimates of the metal endowment. The team estimates that 26 undiscovered deposits occur within the Chu-Sarysu Basin, and that these deposits contain an arithmetic mean of at least 60.5 million metric tons (Mt) of copper and 67,000 metric tons (t) of silver. The undiscovered deposits are in addition to the 7 known deposits that contain identified resources of 27.6 Mt of copper. Sixty percent of the estimated mean undiscovered copper resources are associated with the two permissive tracts that contain the identified resources; the remaining estimated resources are associated with the two tracts that have no known deposits. For the three tracts that contain 95 percent of the estimated undiscovered copper resources, the probability that each tract contains its estimated mean or more is about 40 percent. For the tract with 5 percent of the estimated undiscovered copper resources, the probability that it contains that amount or more is 25 percent.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Sandstone copper assessment of the Chu-Sarysu Basin, Central Kazakhstan
Series title:
Scientific Investigations Report
Series number:
2010-5090
Chapter:
E
Year Published:
2012
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Mineral Resources Program
Description:
Report: vi, 63 p.; Metadata Folder; GIS Data; SIR 2010-5090
Number of Pages:
74
Country:
Kazakhstan
Other Geospatial:
Chu-sarysu Basin
Projection:
Lambert Conformal Conic Projection
Online Only (Y/N):
Y
Additional Online Files(Y/N):
Y