Regional and local constraints on metallogenesis in the Bodie Hills of Nevada and California – A case history on horizontal integration of geospatial data sets

A multifaceted approach of horizontal-data integration is required to investigate
the complex geologic and metallogenic setting of the Bodie Hills region. The factors
influencing regional- and local-scale metallogenesis are compared and discussed in
context of various datasets, analysis techniques and methodologies. From the standpoint
of economic geology, mineralization occurrences in the Bodie Hills are structurally
controlled, low-sulfidation, quartz-adularia-sericite precious metal vein
deposits with an extensive alteration halo. The gravity data suggests a NE-trending,
positive anomaly, resulting from a density contrast between the presumably uplifted
pre-Tertiary basement and Miocene volcanic assemblage in the Bodie Hills. The aeromagnetic
data are dominated by the strong signature of the Miocene volcanism (vents,
flows, etc.) and suggests that the volcanic activity is concentrated along the northeasterly
corridor of basement uplift. Analysis of spaceborne imagery shows the regional
structural setting, which is dominated by NNE and NE-trending lineaments.The highresolution,
narrow-swath, hyperspectral data obtained from airborne sensors, targeted
on the individual districts, allows identification of hydrothermal alteration assemblages,
potential structural mineralization conduits and surface manifestations of mineralization.
Individual segments of the regional-to-local geophysical survey are field
checked and horizontally integrated. The analysis of geophysical data reveal a close
relationship between the basement uplift (source for metals), NE-trending structures
(conduits), volcanic activity (energy), hydrothermal activity (genesis) and mineralization
in Aurora and Bodie. This study suggests that the northeasterly trend of mineralization
in the Bodie Hills may be genetically associated with the initial phase of
Miocene extension and stress accommodation in Western Great Basin during 15–8 Ma.