Download or read book The John Day Formation in the Picture Gorge Quadrangle Oregon written by Robert Griffin Coleman and published by . This book was released on 1949 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Picture Gorge Quadrangle Oregon written by Willis Harkness White and published by . This book was released on 1964 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are seven stratigraphic units exposed in the Picture Gorge quadrangle, a 204-square mile area in east-central Oregon. isolated exposures of pre-Cretaceous serpentinites, metalimestones, and other metamorphic rocks record marine deposition of sands silts, and limy sediments followed by burial, lithification, peridotite intrusion, and several periods of deformation. Intrusion and deformation were accompanied by serpentinization, silcification. and calcite veination. Cretaceous conglomerates and intercalated sandstones, which unconformably overlie the metamorphic rocks, are a result of fluvial deposition in a nearshore or continental environment, burial, lithification, uplift, and erosion. Pebbles were derived from plutonicmetamorphic highlands. The Eocene Clamo Formation unconformably overlies the Cretaceous rocks and is made up of basalt conglomerate, silicified conglomerate, andesite breccias, and andesite flows. The fossiliferous John Day Formation, Oligo-Miocene in age, lies unconformably on the Clamo Formation and is pyroclastic in character. Ash was wind-transported from trachytic-andesitic sources to the west and deposited on land, in lakes, and in swamps. The 2, 400-foot section of volcanic siltstones and waterlaid volcaniclastic rocks includes some basalt near the base and an ash-flow tuff near the middle. The John Day Formation was folded slightly after consolidation. The fissure-fed Middle Mjocene Columbia River Basalt flows, at least 2, 300 feet thick, blanket 124 square miles of the quadrangle. Modal analyses of thin sections from 22 basalt flows suggest that flows cannot be correlated on the basis of mineralogy. Correlation must involve a combination of criteria, such as color, texture, and nature of outcrop, together with mineralogy and chemical analyses. Interfiow breccias, tuffs, volcanic siltstones and sandstones, dikes, and an irregular intrusion are also present. The Columbia River Basalt unconformably overlies the John Day Formation. After emplacement, the basalt flow rocks were folded into the west-trending Sunflower anticline and John Day syncline. Normal faulting occurred on the shared flank of the two folds. The Upper Miocene Mascall Formation lies unconformably upon the Columbia River Basalt. About 400 feet of well-bedded, rhy-. olitic volcanic siltstones and intercalated sand and gravel lenses suggest eoliari and fluvial deposition of ash in lakes and swamps. Folding and faulting occurred along the same trends which were active during Columbia River Basalt time. 'lhe Plio-Pleistocene Rattlesnake Formation rests with pronounced angular unconformity on the Mascall Formation. About 10 feet of poorly consolidated fluvial gravels enclose a 38-foot-thick ash-flow tuff. Pleistocene and recent events include capture of the middle fork of the John Day River, slumping, development of pediments, formation of stone garlands, stone stripes, and talus-free mounds, and deposition of stream gravels. An andesitic, hornblende-bearing white volcanic ash was deposited by wind.

Download or read book Geology of the Spray Quadrangle Oregon with Special Emphasis on the Petrography and Magnetic Properties of the Picture Gorge Basalt written by Donald Hale Lindsley and published by . This book was released on 1960 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geologic Setting of the John Day Country Grant County Oregon written by Thomas P. Thayer and published by . This book was released on 1977 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of Oregon written by Ewart Merlin Baldwin and published by . This book was released on 1976 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geologic Setting of the John Day Country written by and published by . This book was released on 1969 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulletin State of Oregon Department of Geology and Mineral Industries written by Oregon. Department of Geology and Mineral Industries and published by . This book was released on 1937 with total page 160 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:

Download or read book Oregon Geology written by Elizabeth L. Orr and published by . This book was released on 2012 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Easy-to-read, rhyming text depicts different animals dancing.

Download or read book Roadside Geology of Oregon written by David D. Alt and published by Missoula, Mont. : Mountain Press Publishing Company. This book was released on 1978 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introductory chapter briefly reviews Oregon's geology followed by a series of road guides with the local particulars. The authors tell you what the rocks are and what they mean. Useful graphics and charts supplement the text and help you to understan

Download or read book Geologic Sketch of Northwestern Oregon written by Parke Detweiler Snavely and published by . This book was released on 1964 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of the Geology and Mineral Resources of Oregon written by and published by . This book was released on 1971 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of Oregon written by Elizabeth L. Orr and published by . This book was released on 1999 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geologic Field Trips in Northern Oregon and Southern Washington written by John D. Beaulieu and published by . This book was released on 1973 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Stayton Quadrangle Oregon written by Thomas Francis O'Neill and published by . This book was released on 1939 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geological Survey Bulletin written by and published by . This book was released on 1978 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Oregon Part of the Baker 1p0s by 2p0s Quadrangle written by Howard C. Brooks and published by . This book was released on 1976 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: