thumbnail

Tilted middle Tertiary ash-flow calderas and subjacent granitic plutons, southern Stillwater Range, Nevada: cross sections of an Oligocene igneous center

Geological Society of America Bulletin

By:

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

Steeply tilted late Oligocene caldera systems in the Stillwater caldera complex record a number of unusual features including extreme thickness of caldera-related deposits, lack of evidence for structural doming of the calderas and preservation of vertical compositional zoning in the plutonic rocks. The Stillwater caldera complex comprises three partly overlapping ash-flow calderas and subjacent plutonic rocks that were steeply tilted during early Miocene extension. The Job Canyon caldera, the oldest (ca. 29-28 Ma) caldera, consists of two structural blocks. The 25 to 23 Ma Poco Canyon and Elevenmile Canyon calderas and underlying Freeman Creek pluton overlap in time and space with each other. Caldera collapse occurred mostly along subvertical ring-fracture faults that penetrated to depths of >5 km and were repeatedly active during eruption of ash-flow tuffs. The calderas collapsed as large piston-like blocks, and there is no evidence for chaotic collapse. Preserved parts of caldera floors are relatively flat surfaces several kilometers across. -from Author

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Tilted middle Tertiary ash-flow calderas and subjacent granitic plutons, southern Stillwater Range, Nevada: cross sections of an Oligocene igneous center
Series title:
Geological Society of America Bulletin
Volume
107
Issue:
2
Year Published:
1995
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geological Society of America Bulletin
First page:
180
Last page:
200