FRACTURE CONTROL ON THE TERTIARY EPITHERMAL-MESOTHERMAL GOLD
DEPOSITS NORTHERN BLACK-HILLS, SOUTH-DAKOTA
By:HARIRI, MM (HARIRI, MM); LISENBEE, AL (LISENBEE, AL); PATERSON, CJ (PATERSON,
CJ)
EXPLORATION AND MINING GEOLOGY
Volume: 4
Issue: 3
Pages: 205-214
Published: JUL 1995
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Abstract
The schist-, sediment-, and intrusion-hosted Tertiary Au-Ag hydrothermal deposits of the
northern Black Hills, South Dakota are localized and controlled by various types of
fractures. This study is an attempt to distinguish between and discuss the possible causes
of these fractures in three mines: Richmond Hill, Annie Creek - Foley Ridge (ACFR), and Gilt
Edge.
Five models based on the structural and tectonic settings of the northern Black Hills are
proposed for the fracture origin. In Richmond Hill mine, mineralized fractures within the
schist-hosted deposits are in the form of veinlets and stockworks. Larger veins filling open
spaces along schistosity planes are also present. Fractures in Richmond Hill mine arerelated to breccia pipe emplacement and influenced by the Precambrian foliation.
Fractures in sediment-hosted (ACFR) and intrusion-hosted (Gilt Edge) deposits are mode I
systematic joints. These fractures, and similar ones examined in seven locations outside the
mines, are related mostly to the formation of the Lead-Deadwood dome. Fracture trends
vary from one area to another depending on their location with respect to the dome. Other
factors, such as the Black Hills uplift, pluton emplacement, and Precambrian foliation, may
also affect the fracture trends. The proximity of the mines to domes formed by multiple
intrusions, the associated fracture patterns and density, and existence of breccias, may be
used in exploration for similar deposits in the northern Black Hills or other areas of similar
geologic settings.
Keywords
Author Information
Reprint Address: HARIRI, MM (reprint author)
KING FAHD UNIV PETR & MINERALS,DEPT EARTH SCI,DHAHRAN 31261,SAUDI ARABIA.
Organization-Enhanced Name(s)
King Fahd University of Petroleum & Minerals
Document Information
Document Type:Article
Language:English
Accession Number: WOS:A1995TG84300004
ISSN: 0964-1823