The Columbia Plateau, Oregon Plateau, Snake River Plain, and Northern Nevada Rift
compose a single magmatic system containing all the essential characteristics ascribed to a …

The origin of the large range of compositional diversity encompassed by primitive arc
magmas and the respective roles of mantle heterogeneity versus slab-derived contributions …

Crustal contamination of basalts located in the western United States has been generally
under-emphasized, and much of their isotopic variation has been ascribed to multiple and …

We present the geologic history of the High Rock caldera complex (HRCC; Nevada, USA), a
major mid-Miocene silicic center associated with flood basalt volcanism. Based on 70 …

Continental flood basalts are more prone to compositional modification from passage
through thicker and (or) more felsic crust in comparison to their oceanic counterparts. The …

Chemically primitive late Cenozoic tholeiitic basalts from the northwestern USA have Os-
isotopic compositions more radiogenic than observed for most basalts from the ocean …

Abstract The John Day Formation of north-central Oregon preserves a succession of
speciose, superposed Oligocene through early Miocene mammalian faunas that establish …

A major, abrupt, southward decline in elevation (∼ 800 m) with an accompanying increase
in Bouguer gravity anomaly (∼ 80 mGal) crosses a seismically active region of southern …

A variety of cognate basalt to basaltic andesite inclusions and dacite pumices occur in the 7-
Ma Rattlesnake Tuff of eastern Oregon. The tuff represents∼ 280 km 3 of high-silica rhyolite …

ABSTRACT The La Grande–Owyhee eruptive axis in eastern Oregon is an~ 300-km-long,
north-northwest–trending, middle Miocene to Pliocene volcanic belt located along the …