This paper presents geologic evidence from the Tharsis rise of Mars for local operation of plate tectonics processes. Specifically, the temporal and spatial distribution of volcanism, the size of volcanoes, and the formation of faults can all be explained by plate subduction. This process is similar to the formation of "the Ring of Fire" around the Pacific Ocean on Earth.
Earliest Cretaceous Pacificward offset of the Klamath Mountains salient, NW California-SW Oregon
W.G. Ernst, Stanford University, Geological & Environmental Sciences, Building 320, Room 118, Stanford, California 94305-2115, USA. Posted online 14 Nov. 2012; http://dx.doi.org/10.1130/L247.1.
A great volcanic-plutonic curvilinear arc (similar to the modern Circumpacific Andean, Alaskan-Aleutian, and Kamchatka-Kuril-Japan arcs) began forming along the margin of North America about 170 million years ago, reflecting eastward subduction of the Farallon oceanic lithosphere. The igneous arc stretched from at least the southern extent of Baja California through the Peninsular Ranges of southern California and the mighty Sierra Nevada Range northward into the Klamath Mountains of NW California and SW Oregon; this same arc probably continued on into the Blue Mountains of eastern Oregon. After about 30 million years of sustained arc volcanism and granitic intrusion, the Klamath Mountains province was gradually displaced westward about 200 km from the igneous belt, and while magmatic activity continued on until about 85-80 million years ago both north and south of the Klamath Mountains, such activity did not occur in the westward projecting salient. W.G. Ernst hypothesizes here that the Farallon oceanic plate consisted of old, thick oceanic lithosphere but at the latitude of NW California-SW Oregon, a relatively thin oceanic plate segment impinged a
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