Volcanoes to Vineyards: Geologic Field Trips through the Dynamic Landscape of the Pacific Northwest
This volume contains guides for 33 geological field trips offered in conjunction with the October 2009 GSA Annual Meeting in Portland, Oregon. Showcasing the region’s geological diversity, the peer-reviewed papers included here span topics ranging from accreted terrains and mantle plumes to volcanoes, floods, and vineyard terroir. Locations visited throughout Oregon, Washington, and Idaho encompass Astoria to Zillah. More than just a series of maps, the accompanying descriptions, observations, and conclusions offer new insights to the geologic processes and history of the Pacific Northwest insights that will inspire readers to put their boots on the evidence (or perhaps sip it from a glass of Pinot!) as they develop their own understanding of this remarkable and dynamic corner of the world.
Late Triassic to Late Jurassic petrotectonic history of the Oregon Klamath Mountains
-
Published:January 01, 2009
-
CiteCitation
Doug Yule, Tom Wiley, M. Allan Kays, Robert Murray, 2009. "Late Triassic to Late Jurassic petrotectonic history of the Oregon Klamath Mountains", Volcanoes to Vineyards: Geologic Field Trips through the Dynamic Landscape of the Pacific Northwest, Jim E. O’Connor, Rebecca J. Dorsey, Ian P. Madin
Download citation file:
- Share
ABSTRACT
This field guide describes stops in the Oregon Klamath Mountains that visit near-complete ophiolite sections, pre- and post-accretion arc plutons, greenschist- to amphibolite-grade metamorphosed wallrocks, arc volcanic rocks, and interbedded chert, argillite, and olistostromal deposits. Structural features at these stops include local- and regional-scale folds and faults, as well as penetrative metamorphic fabrics such as slaty cleavage, gneissic layering, and mineral lineations. The geologic history here reveals a period of Late Triassic and Jurassic ophiolite and oceanic-arc formation followed by Middle Jurassic terrane accretion, tectonic mélange formation, and continued oceanic arc magmatism. Rifting from ca. 165 to 160 Ma produced the Rogue-Chetco arc, Josephine ophiolite, and remnant arc comprised of older Klamath Mountains terranes. Deformation and magmatism during the Late Jurassic Neva-dan orogeny accreted this active arc–inter-arc basin–remnant arc triad to western North America, producing the lithotectonic belts observed today. The Oregon Klam-ath Mountains therefore provide an exceptional opportunity to examine the deep to shallow levels of multi-phase oceanic lithosphere and deformational features related to the accretion of these terranes to the continental margin.
- California
- Coast Ranges
- Condrey Mountain Schist
- faults
- field trips
- guidebook
- Hayfork Terrane
- igneous rocks
- Jackson County Oregon
- Josephine County Oregon
- Josephine Ophiolite
- Jurassic
- Klamath Mountains
- Mesozoic
- metamorphic rocks
- North America
- olistostromes
- ophiolite
- Oregon
- peridotites
- plutonic rocks
- road log
- sedimentary structures
- soft sediment deformation
- tectonics
- Triassic
- Trinity Complex
- ultramafics
- United States
- Upper Jurassic
- Upper Triassic
- Yolla Bolly Terrane