The Cascade Range in the Pacific Northwest, USA, developed as an Eocene to recent volcanic arc along the Pacific/North American ocean-continent subduction zone. The volcanic arc is characterized by temporally and spatially variable magmatism. Crustal deformation that accompanied development of the arc ...
Mount Saint Helens,Mount St. Helens,Mt. St. Helens- an active volcano in the Cascade Range in southwestern Washington; erupted violently in 1980 after 123 years of inactivity Mount Adams,Adams- a mountain peak in southwestern Washington in the Cascade Range (12,307 feet high) ...
and most volcanologists consider the volcanoes here to be part of the Cascade chain. The Cascade volcanoes have formed as a result of the subduction of the Juan de Fuca, Gorda, and Explorer Plates beneath the North American Plate along the Cascadia Subduction Zone, and the range includes some...
We compiled available studies of 33 earthquake mainshocks spanning a magnitude rangeMW[3.7–9.0] with the aim of summarizing the inferred physical processes that may drive their occurrence (Fig.2a). The mainshock inventory includes earthquakes that occurred under various stress, kinematics, fault load...
The familiar snow-clad peaks of the Cascade Range are part of a 1,300 km (800 mi) chain of volcanoes, which extends from northern California to southern British Columbia. The volcanoes are the result of the slow slide of dense oceanic crust as it sinks beneath North America (subduction)...
The subduction of the Juan de Fuca tectonic plate beneath the North American plate is the ultimate driver for the formation of the Cascade Range, as well as many of the earthquakes the Northwest has experienced. Subduction results in deep melting of the Earth's mantle, and the magma then hea...
The geometry of the Hikurangi megathrust is not well constrained in its Southern end12: dipping angles assumed in previous studies range from 12° to 25°1,5. Large-scale ground deformations have then been explained by either slip on the subduction interface (e.g., refs. 1,5) or by ...
6.1.4. Assessment of Subduction Input [35] For primitive samples at Salal Glacier and Bridge River, Ba/Nb values lie within the range of Hawaiian basalts and coincide with melting curves for enriched mantle (at ∼2–5% partial melt) (Figure 8), pointing to the likelihood that a slab-der...
Hart GL (2002) Isotope study of magmatic processes and crustal recycling in subduction zone environments in the Cascade range of northwestern US. [Ph.D. thesis] University of Wisconsin-Madison, 210 pHart GL (2002) Isotope study of magmatic processes and crustal recycling in subduction zone ...
Detailed major and trace element studies of volcanic rocks from Jefferson, Rainier, and Shasta stratovolcanoes in the Cascade Range indicate that each volcano has distinct geochemical distribution patterns. Silica variation diagrams are not smooth nor, in general, continuous for any volcano. Portions ...