Water-Quality Effects on Baker Lake of Recent Volcanic Activity at Mount Baker, Washington (open access)

Water-Quality Effects on Baker Lake of Recent Volcanic Activity at Mount Baker, Washington

From introduction: The purpose of this report is to evaluate and describe relationships between the volcanic activity on Mount Baker and the possible impacts on Baker Lake water.
Date: 1977
Creator: Bortleson, Gilbert Carl; Wilson, R. T. & Foxworthy, B. L.
System: The UNT Digital Library
Paleozoic-Mesozoic Boundary in the Berry Creek Quadrangle, Northwestern Sierra Nevada, California (open access)

Paleozoic-Mesozoic Boundary in the Berry Creek Quadrangle, Northwestern Sierra Nevada, California

Abstract: Structural and petrologic studies in the Berry Creek quadrangle at the north end of the western metamorphic belt of the Sierra Nevada have yielded new information that helps in distinguishing between the chemically similar Paleozoic and Mesozoic rocks. The distinguishing features are structural and textural and result from different degrees of deformation. Most Paleozoic rocks are strongly deformed and thoroughly recrystallized. Phenocrysts in metavolcanic rocks are granulated and drawn out into lenses that have sutured outlines. In contrast, the phenocrysts in the Mesozoic metavolcanic rocks show well-preserved straight crystal faces, are only slightly or not at all granulated, and contain fewer mineral inclusions than do those in the Paleozoic rocks. The groundmass in the Paleozoic rocks is recrystallized to a fairly coarse grained albite-epidote-amphibole-chlorite rock, whereas in the Mesozoic rocks the groundmass is a very fine grained feltlike mesh with only spotty occurrence of well-recrystallized finegrained albite-epidote-chlorite-actinolite rock. Primary minerals, such as augite, are locally preserved in the Mesozoic rocks but are altered to a mixture of amphibole, chlorite, and epidote in the Paleozoic rocks. In the contact aureoles of the plutons, and within the Big Bend fault zone, which crosses the area parallel to the structural trends, all …
Date: 1977
Creator: Hietanen, Anna Martta
System: The UNT Digital Library
Stratigraphy and Microfaunas of the Oquirrh Group in the Southern East Tintic Mountains, Utah (open access)

Stratigraphy and Microfaunas of the Oquirrh Group in the Southern East Tintic Mountains, Utah

Abstract: The Oquirrh Group of Pennsylvanian and Permian age in the southern East Tintic Mountains, Utah, is more than 15,000 feet (4,572 m) thick and consists of an incomplete section of the West Canyon Limestone (Morrowan) 960 feet (293 m) thick, a nearly complete section of the Butterfield Peaks Formation (Atokan(?) and Des Moinesian) about 5,800 feet (1,768 m) thick, a complete section of the Bingham Mine Formation (Missourian) 3,200-3,400 feet thick (975-1,036 m), and a complete section of the newly named Furner Valley Limestone (Missourian to Wolfcampian) 5,000-6,000 feet (1,524-1,829 m) thick. The formations below the Furner Valley Limestone are generally similar to their counterparts in their type areas in the central and southern Oquirrh Mountains but are somewhat thinner and less arenaceous. The Furner Valley Limestone, more than 90 percent carbonate, is apparently unique. Strata of the same age in the Wasatch, Stansbury, Cedar, Hogup, and Promontory Mountains in Utah are all considerably arenaceous; in the southern Oquirrh Mountains in the upper plate of the Midas thrust fault they have been largely removed by erosion. The Oquirrh Group in the East Tintic Mountains is overlain by the Diamond Creek Sandstone; the latter, in turn, is overlain by the …
Date: 1977
Creator: Morris, H. T.; Douglass, Raymond C. & Kopf, Rudolph W.
System: The UNT Digital Library
Studies Related to the Charleston, South Carolina, Earthquake of 1886: a Preliminary Report (open access)

Studies Related to the Charleston, South Carolina, Earthquake of 1886: a Preliminary Report

From abstract: The seismic history of the southeastern United States is dominated by the 1886 earthquake near Charleston, S.C. An understanding of the specific source and the uniqueness of the neotectonic setting of this large earthquake is essential in order to properly assess seismic hazards in the southeastern United States. Such knowledge will also contribute to the fundamental understanding of intraplate earthquakes and will aid indirectly in deciphering the evolution of Atlantic-type continental margins. The 15 chapters in this volume report on the first stage of an ongoing multidisciplinary study of the Charleston earthquake of 1886.
Date: 1977
Creator: Rankin, Douglas W.
System: The UNT Digital Library
Revisions of Ulmus and Zelkova in the Middle and Late Tertiary of Western North America (open access)

Revisions of Ulmus and Zelkova in the Middle and Late Tertiary of Western North America

Abstract: Examination of previously described and some undescribed leaves of Ulmus and Zelkova from the later Oligocene, Miocene, and Pliocene of western North America indicates that at least eight species of Ulmus and two species of Zelkova are represented. Three new species are described: Ulmus chaneyi, U. knowltoni, and Zelkova browni.
Date: 1977
Creator: Tanai, Toshimasa & Wolfe, Jack A.
System: The UNT Digital Library