Digital data for preliminary geologic map of the Mount Hood 30- by 60-minute quadrangle, northern Cascade Range, Oregon

Data Series 906
Oregon Department of Geology and Mineral Industries
By: , and 

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Abstract

The Mount Hood 30- by 60-minute quadrangle covers the axis and east flank of the Cascade Range in northern Oregon. Its namesake, Mount Hood volcano, dominates the view in the northwest quarter of the quadrangle, but the entire area is underlain by Oligocene and younger volcanic and volcaniclastic rocks of the Cascade Range. Since the time of the Columbia River Basalt Group about 15 million years (m.y.) ago, the locus and composition of Cascade Range volcanism have shifted sporadically across the map area. Andesitic eruptions were predominant in the western part from about 14 to 10 m.y. ago (Salmon and Sandy Rivers area), producing the Rhododendron Formation and overlying lava flows. From about 8 to 6.5 m.y. ago, lithic pyroclastic debris of the Dalles Formation was shed by chiefly andesitic volcanoes in the north-central part of the map area (Hood River valley escarpment). Andesitic to dacitic volcanism was again predominant about 5 to 3 m.y. ago, with known eruptive centers located from Lookout Mountain westward to Lolo Pass, probably including the area now occupied by Mount Hood. A major episode of mafic volcanism-basalt and basaltic andesite-began about 3-4 m.y. ago and lasted until about 2 m.y. ago. Volcanism since about 2 m.y. ago has been concentrated along the axis of the High Cascades. North and south of Mount Hood these youngest rocks are predominantly basaltic andesite lava flows; whereas at Mount Hood itself, andesite is predominant, forming pyroclastic and debris-flow deposits and lava flows.

This geodatabase contains information derived from legacy mapping that was published in 1995 as U.S. Geological Survey Open-File Report 95-219. The main component of this publication is a geologic map database prepared using geographic information system (GIS) applications. Included are pdf files to view or print the map sheet, the accompanying pamphlet from Open-File Report 95-219, and links to the original publication, which is available as scanned files in pdf format.

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Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Digital data for preliminary geologic map of the Mount Hood 30- by 60-minute quadrangle, northern Cascade Range, Oregon
Series title Data Series
Series number 906
DOI 10.3133/ds906
Year Published 2014
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Volcano Science Center
Description Report: 6 p.; Plate: 47.99 x 35.98 in.; 5 Tables
Country United States
State Oregon
Other Geospatial Northern Cascade Range
Online Only (Y/N) Y
Additional Online Files (Y/N) N
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