The Origin of Sheet Fractures in the Galore Creek Copper Deposits, British Columbia

1971 ◽  
Vol 8 (6) ◽  
pp. 704-711 ◽  
Author(s):  
Donald G. Allen
Keyword(s):  
British Columbia ◽  
Hydrothermal Alteration ◽  
Porphyry Copper ◽  
Surface Feature ◽  
Porphyry Copper Deposits ◽  
Volume Increase ◽  
Copper Deposits ◽  
Feature Characteristic

A surface feature characteristic of the Galore Creek copper deposits is a set of well-developed closely-spaced fractures, termed sheet fractures. The formation of these fractures is attributed to the widespread presence of anhydrite, a hydrothermal alteration mineral associated with copper. The fractures apparently developed as a consequence of the volume increase due to hydration of the anhydrite to gypsum by meteoric water.The Galore Creek deposits have many characteristics of porphyry copper deposits, in many of which anhydrite or gypsum has been reported. Anhydrite may be responsible for the development of sheet fractures elsewhere.

Seismic and potential‐field imaging of the Guichon Creek batholith, British Columbia, Canada, to delineate structures hosting porphyry copper deposits

Geophysics ◽  
2000 ◽  
Vol 65 (5) ◽  
pp. 1418-1434 ◽  
Author(s):  
Baishali Roy ◽  
Ron M. Clowes
Keyword(s):  
British Columbia ◽  
Seismic Reflection ◽  
Porphyry Copper ◽  
Regional Scale ◽  
Low Grade ◽  
Depth Range ◽  
Porphyry Copper Deposits ◽  
Near Surface ◽  
Copper Deposits ◽  
South Central

The Guichon Creek batholith (GCB), located in south‐central British Columbia, contains several large, low‐grade copper deposits of considerable economic importance. The surface geology of the Guichon batholith and its surrounding region have been well mapped; however, little information about subsurface features is available. The batholith consists of four major phases, emplaced radially outward, which can be separated on the basis of their texture and composition. Previous interpretation of gravity data suggests a mushroom‐shaped structure for the batholith. Data from Lithoprobe seismic reflection line 88-11, acquired across the batholith in 1988, reveal weakly coherent east‐dipping reflections on the west side and west‐dipping reflections on the east in the upper 10 km. To determine if these are related to structures associated with the batholith, we reprocessed the upper 6 s with particular emphasis on applications of signal enhancement techniques (e.g., pattern recognition methods, refraction statics, dip moveout corrections) and correlation of the improved subsurface images with the geological environment associated with porphyry copper deposits. Low near‐surface velocities correlate well with the phases of the batholith hosting the major copper deposits, which structurally lie in faulted and brecciated regions. Although the top 1.5 km cannot be imaged by the regional‐scale seismic reflection data, the reprocessed seismic section helps define the edges of the batholith, its various concentric phases, and the stem in the depth range of 1.5 to 10 km. The seismic results are complemented by 2.5-D (profile sense) modeling and 3-D inversion of regional‐scale gravity and high‐resolution aeromagnetic data. These show a low‐density and low‐magnetic‐susceptibility region associated with the batholith that extends to more than 10 km depth. The region of active mining interest lies above a circular low‐susceptibility area at 2 km depth and a low‐velocity region. Integrated interpretation of geophysical results and geological observations indicates the GCB is a funnel‐shaped feature in which mineralization is located above the stem of the batholith.

Fluid inclusion geochemistry of the Granisle and Bell porphyry copper deposits, British Columbia

1980 ◽  
Vol 75 (1) ◽  
pp. 45-61 ◽  
Author(s):  
J. W. J. Wilson ◽  
S. E. Kesler ◽  
P. L. Cloke ◽  
W. C. Kelly
Keyword(s):  
British Columbia ◽  
Fluid Inclusion ◽  
Porphyry Copper ◽  
Porphyry Copper Deposits ◽  
Copper Deposits

scholarly journals Application of Dirichlet Process and Support Vector Machine Techniques for Mapping Alteration Zones Associated with Porphyry Copper Deposit Using ASTER Remote Sensing Imagery

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1235
Author(s):  
Mastoureh Yousefi ◽  
Seyed Hasan Tabatabaei ◽  
Reyhaneh Rikhtehgaran ◽  
Amin Beiranvand Pour ◽  
Biswajeet Pradhan
Keyword(s):  
Hydrothermal Alteration ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Training Data ◽  
Support Vector ◽  
Porphyry Copper Deposits ◽  
Copper Deposits ◽  
Alteration Zones ◽  
Hydrothermal Alteration Zones

The application of machine learning (ML) algorithms for processing remote sensing data is momentous, particularly for mapping hydrothermal alteration zones associated with porphyry copper deposits. The unsupervised Dirichlet Process (DP) and the supervised Support Vector Machine (SVM) techniques can be executed for mapping hydrothermal alteration zones associated with porphyry copper deposits. The main objective of this investigation is to practice an algorithm that can accurately model the best training data as input for supervised methods such as SVM. For this purpose, the Zefreh porphyry copper deposit located in the Urumieh-Dokhtar Magmatic Arc (UDMA) of central Iran was selected and used as training data. Initially, using ASTER data, different alteration zones of the Zefreh porphyry copper deposit were detected by Band Ratio, Relative Band Depth (RBD), Linear Spectral Unmixing (LSU), Spectral Feature Fitting (SFF), and Orthogonal Subspace Projection (OSP) techniques. Then, using the DP method, the exact extent of each alteration was determined. Finally, the detected alterations were used as training data to identify similar alteration zones in full scene of ASTER using SVM and Spectral Angle Mapper (SAM) methods. Several high potential zones were identified in the study area. Field surveys and laboratory analysis were used to validate the image processing results. This investigation demonstrates that the application of the SVM algorithm for mapping hydrothermal alteration zones associated with porphyry copper deposits is broadly applicable to ASTER data and can be used for prospectivity mapping in many metallogenic provinces around the world.

Hydrothermal alteration in Puerto Rican porphyry copper deposits

1973 ◽  
Vol 68 (8) ◽  
pp. 1329-1334 ◽  
Author(s):  
Dennis P. Cox ◽  
Richard R. Larson ◽  
Richard B. Tripp
Keyword(s):  
Puerto Rican ◽  
Hydrothermal Alteration ◽  
Porphyry Copper ◽  
Porphyry Copper Deposits ◽  
Copper Deposits
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