REPORT:
Eruptive History of Mount Mazama and Crater Lake Caldera, Cascade Range, U.S.A.

Table of Contents

• Abstract
• Introduction
• Terminology
• Geologic Setting
  • Regional tectonic features
  • Alignments of monogenetic basaltic vents
  • Local stress field
  • Foundations of Mount Mazama
  • Volcanic rocks adjacent to Mount Mazama
    • Cones and domes east of the caldera
    • Southern rhyodacites
• Petrography
  • Lava flows and pyroclastic rocks
  • Mafic inclusions
• Pleistocene Mount Mazama
  • A cluster of pre-Wisconsin polygenetic volcanoes
    • Phantom Cone
    • Danger Bay
    • Dutton Cliff
    • Sentinel Rock
    • Llao Rock
    • Merriam Point
    • Hydrothermal alteration
    • Implications for pre-Wisconsin topography
  • Wisconsin volcanic rocks and glacial deposits
    • Cloudcap Bay
    • Hillman Peak
    • Early Wisconsin glacial deposits
    • Early Wisconsin lavas
    • Dacitic lavas of Scott Bluffs
    • Tephra of "Pumice Castle"
    • Middle Wisconsin lava flows
  • Late Pleistocene dacitic rocks
    • Dacite debris in Munson Valley and on the west caldera rim
    • Sharp Peak domes
    • Dome east of Llao Rock
    • Forgotten Crater
    • Palisade flow
  • Late-Wisconsin topography
  • Extra-caldera monogenetic cones and small shields
• Precursors to the Climactic Eruption
  • Preclimactic rhyodacitic lava flows and tephra
    • Redcloud eruptive center
    • Llao Rock eruptive center
    • Grouse Hill lava flow and dome
    • Cleetwood eruptive center
    • Vent distribution
    • Initiation of the climactic eruption
• The Climactic Eruption
  • Single-vent phase
  • Climactic pumice fall
  • Wineglass Welded Tuff
  • Ring-vent phase
    • Proximal facies
    • Medial facies
    • Distal facies
    • Mobility of the ash flows
    • Eruption mechanism
    • Erosion by the ash flows
  • Timing of caldera collapse
  • Collapse versus enlargement of a funnel-shaped vent
  • Radiocarbon ages
  • The "volume problem"
• Postcaldera Volcanism
• Provisional Model for the Mazama Magmatic System
  • Evolution of the Pleistocene system
  • The climactic magma chamber
• Acknowledgments
• References

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