Download or read book Geology of Part of the Northeast Quarter of the Mitchell Quadrangle Oregon written by Robert Lynn Patterson and published by . This book was released on 1966 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis area covers 165 square miles including the greater part of the northeastern quarter of the Mitchell quadrangle in north-central Oregon. The three stratigraphic units exposed in the area consist of a variety of Tertiary volcanic rocks including the Clarno Formation, the John Day Formation, and the Columbia River Basalt. The Clarno Formation of Eocene to Early Oligocene age is the oldest rock unit in the thesis area. From oldest to youngest, the mapped units include volcanic boulder conglomerates, andesite and basalt flows and flow breccias, tuffaceous sandstones intercalated with lava flows, and twelve plugs and dikes of andesite and basalt. The composition, lack of sorting, stratigraphic and structural features, and the included flora indicate that the volcanic boulder conglomerates were deposited as mudflows on a terrain of high relief in a humid, subtropical climate. Andesite lavas were extruded intermittently during deposition of the mudflows resulting in complex intertonguing of the two rock types. Later, Clarno lavas poured from numerous isolated fissures and covered the volcanic boulder conglomerates. Near Middle Oligocene time the formation was folded into a broad NE-trending anticline which swings sharply eastward in the north-central half of the area. Following uplift, the Clarno rocks were eroded into a surface of moderate relief and thick fossil soils developed on scoriaceous portions of the lava flows. The John Day Formation of Late Oligocene to Early Miocene age consists of ash flows and ash falls of acid to intermediate pyroclastic material which were deposited unconformably on the deformed and eroded Clarno rocks. These pyroclastics were erupted from unknown local sources, and probably from distant volcanoes to the west. Much of the material deposited on the pre-Miocene anticlinal crest was reworked by streams and formed thick tuff beds on the flanks of the fold. In Middle Miocene time the consolidated John Day Formation was slightly folded parallel to pre-Miocene anticlinal trends and underwent erosion. The Columbia River Basalt was extruded from fissures onto the tuffs during Middle Miocene time. Following deposition the thick layers of basalt were gently folded as the pre-Miocene anticlinal trend again served as the pattern for mild uplift and deformation in latest Miocene time. Rocks younger than Middle Miocene were either never deposited on the basalt plateaus of the area, or have been completely removed by erosion. In Pleistocene and Recent time the plateaus were dissected and the flows were eroded from the anticlinal crest. Landslide, fluvial, and terrace deposits were laid down in the valleys. White volcanic ash was transported by wind from an unknown source and intercalated with Recent fluvial and slope wash deposits.

Download or read book Geology of the Northeast Portion of the Mitchell Butte Quadrangle Oregon written by Norman Calvin Privrasky and published by . This book was released on 1953 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Northeast Quarter of the Bone Mountain Quadrangle Oregon written by Nils Poorbaugh Johannesen and published by . This book was released on 1972 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Northeast Quarter of the Powers Quadrangle Oregon written by Paul Dennis Hess and published by . This book was released on 1967 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Northeast Quarter of the Huntington Quadrangle Oregon written by Norman Jonathan Berry and published by . This book was released on 1956 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the East Central Portion of the Mitchell Butte Quadrangle Oregon written by Raymond Ervin Corcoran and published by . This book was released on 1953 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of Part of the Mitchell Quadrangle Jefferson and Crook Counties Oregon written by James Nick Lukanuski and published by . This book was released on 1963 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Northeast One quarter of the Prineville Quadrangle North central Oregon written by Neil J. Bingert and published by . This book was released on 1983 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Northeast Quarter of Camas Valley Quadrangle Douglas County Oregon written by James Francis Moore and published by . This book was released on 1957 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Lower Sucker Creek Area Mitchell Butte Quadrangle Oregon written by Philip Weldon Porter and published by . This book was released on 1953 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Marshall Butte Area and Vicinity Mitchell Quadrangle Oregon written by Loren Bruce McIntyre and published by . This book was released on 1953 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Sheep Mountain Area and Vicinity Mitchell Quadrangle Oregon written by James Castles Swarbrick and published by . This book was released on 1953 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Geology of the Northeast Quarter of the Dutchman Butte Quadrangle Southwest Oregon written by Rauno K. Perttu and published by . This book was released on 1976 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theses and Dissertations on the Geology of Oregon written by and published by . This book was released on 1982 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Double Mountain Grassy Mountain Area Mitchell Butte Quadrangle Oregon written by Robert Alvin Doak and published by . This book was released on 1953 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Northeast Third of the Ritter Quadrangle Oregon written by George Martz Thomas and published by . This book was released on 1956 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Description of the Geology of the Kerby Quadrangle Oregon written by Francis Gerritt Wells and published by . This book was released on 1949 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: