Petroleum potential of north-central Oregon: an overview

Conference · Sat Aug 01 04:00:00 EDT 1987 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:5752560

Fisk, L H

Except for a few erosional inliers, north-central Oregon is covered by a blanket of tertiary volcanic and volcaniclastic rocks which had a thick sequence of Cretaceous and Tertiary sedimentary rocks that have led previous investigators to draw negative conclusions regarding the petroleum potential of the region. Present in the prevolcanic sequence are all the prerequisites for petroleum generation and accumulation: source rocks, thermal maturity, reservoir rocks, seals, and traps. Organic-rich source rocks include marine mudstones of the Lower Cretaceous Mitchell Formation black shales and coals of the Paleocene-Eocene Herren Formation, and lacustrine shales and coals of the Eocene-Oligocene Clarno Formation. The Type II and III kerogens are thermally mature. Petroleum seeps and shows are further evidence that hydrocarbons have been generated. Potential reservoir rocks include proximal fan facies and turbidite sandstones of the Mitchell Formation, fluvial channel sandstones of the Herren Formation volcaniclastic sandstones and fractured flows and ignimbrites in the Clarno and John Day Formations, and scoriaceous and brecciated flows in the Columbia River Basalt. Tuffaceous claystones form excellent seals. Traps of several kinds are present including large untested domes and anticlines, abundant fault traps, and facies traps in the interfingering sand-shale sequences. Thus, despite abundant volcanic activity and periodically rejuvenated tectonic activity, north-central Oregon has the potential to yield large quantities of both oil and gas.

• Research Organization: Loma Linda Univ., Riverside, CA
• OSTI ID: 5752560
• Report Number(s): CONF-870915-
• Conference Information: Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 71:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
BITUMINOUS MATERIALS
BLACK SHALES
CARBONACEOUS MATERIALS
CENOZOIC ERA
CHATTANOOGA FORMATION
CRETACEOUS PERIOD
ENERGY SOURCES
EXPLORATION
FEDERAL REGION X
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC TRAPS
MATERIALS
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
OIL SHALES
OREGON
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCE POTENTIAL
RESOURCES
SOURCE ROCKS
TERTIARY PERIOD
USA