The Grants Pass Batholith of Cretaceous age has intruded the
Triassic Applegate Group and metasedimentary rocks of the Jurassic
Galice Formation in the Murphy area of Josephine County, southwest
Oregon. The Applegate Group, mafic volcanic and sedimentary rock,
has been partially (nonequilibrium) metamorphosed under greenschist
facies conditions. The batholith, a...
Samarium-neodymium data for authigenic ferromanganese
sediments from the oceans indicate that the Atlantic, Pacific, and
Indian Oceans each have a distinct range in Nd isotopic composition,
all of which are far less than ¹⁴³Nd/¹⁴⁴Nd ratios of source rocks with
oceanic affinities. Direct measurements of the Nd isotopic composition
of seawater...
The Paleocene-lower Eocene volcanic rocks of the southern Oregon Coast Range
Roseburg Formation are the oldest remnant eruptive sequence of an oceanic islandseamount
province which is presently exposed along a north-south lineament that stretches
from Vancouver, B.C. into southwestern Oregon. This seamount terrane is thought to
have formed on the...
The Oregon Mountain area contains an ophiolitic assemblage of rocks which can he divided into two major zones on the basis of lithology: (1) spilite and diabase, with minor chert, and (2) plagiogranite, hornblende gabbro, cumulate gabbro and cumulate ultramafic rocks. The two zones have a total estimated thickness of...
