Publications
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Overview of Mount St. Helens volcanic eruption
Dormant since 1857, Mount St. Helens Volcano in southwestern Washington stirred from its repose to erupt on March 27, 1980, following a week of premonitory earthquake activity. The eruption was the first in the conterminous United States since the 1914-1921 activity of Lassen Peak, California. The eruptive activity through May 17 was intermittent and relatively mild, but the accompanying seismic a
Authors
Robert I. Tilling
Pacific Coast coccolith stratigraphy between Point Conception and Cabo Corrientes, Deep Sea Drilling Project Leg 63
DSDP Leg 63 recovered Neogene coccoliths from south of Point Conception, California (Site 467), to north of Cabo Corrientes, Mexico (Site 473), as part of a traverse exploring the sedimentary record of the California Current along the Pacific Coast. A combination of temperate and tropical zonations were used to date Leg 63 coccolith assemblages because of intergradations of warm and cool species a
Authors
David Bukry
Silicoflagellate stratigraphy of offshore California and Baja California, Deep Sea Drilling Project, Leg 63.
Quantitative study of middle and upper Miocene silicoflagellate assemblages from Pacific Coast Sites 467 and 469 to 472 has permitted identification of warm- and temperate-water biostratigraphic zones and the formulation of a model for relative paleotemperature values (Ts) on the basis of warm- and temperate-genera abundances. Geographic and temporal trends in Ts for Pacific Coast assemblages are
Authors
David Bukry
Cenozoic coccoliths from the Deep Sea Drilling Project
Coccoliths, as the dominant constituent of many Deep Sea Drilling Project cores, have provided the means of rapid and detailed biostratigraphic zonation to help guide ocean-sediment coring operations aboard D.V. Glomar Challenger. The Cenozoic has been divided into 50 to 60 zones and subzones which are most effective for middle- and low- latitude sites. Because key stratigraphic coccoliths have pr
Authors
David Bukry
Synthesis of silicoflagellate stratigraphy for maestrichtian to quaternary marine sediment
Cosmopolitan and low-latitude silicoflagellate distributions determined from Deep Sea Drilling Project cores are synthesized into a sequence of 23 biostratigraphic zones and subzones for tropical and subtropical ocean areas. The stratigraphic relation of major morphologic changes in silicoflagellates from all areas is summarized. Two new Neogene subzones, one new Paleogene subzone, one new species
Authors
David Bukry
Late Cenzoic rhyolites from the Kern Plateau, southern Sierra Nevada, California.
Four late Cenozoic rhyolite domes lie atop the Kern Plateau, 30 to 40km S-SE of Mount Whitney. K-Ar and 40Ar/39Ar dating shows that Monache, Templeton, and Little Templeton Mountains are all about 2.4Ma old; a small dome nearby is approx 0.2Ma old. The three older rhyolites have SiO2 = 73-74% and have steep, fractionated rare earth element (REE) patterns; the youngest has SiO2 = 76% and a concave-
Authors
C. R. Bacon, W. A. Duffield
Pleistocene high-silica rhyolites of the Coso volcanic field, Inyo County, California
The high-silica rhyolite domes and lava flows of the bimodal Pleistocene part of the Coso volcanic field provide an example of the early stages of evolution of a silicic magmatic system of substantial size and longevity. Major and trace element compositions are consistent with derivation from somewhat less silicic parental material by liquid state differentiation processes in compositionally and t
Authors
C. R. Bacon, R. Macdonald, R. L. Smith, P. A. Baedecker
Guides to some volcanic terranes in Washington, Idaho, Oregon, and Northern California
This guidebook arose out of a series of field trips held in conjunction with the Pacific Northwest American Geophysical Union meeting held in Bend, Oregon, September 1979. The PNAGU meeting included special volcanology sessions planned by William I. Rose, Jr., Bruce A. Nolf, amd David A. Johnston. Publication of the guidebook volume was originally planned for early 1980 by the Oregon Department of
Authors
David A. Johnston, Julie M. Donnelly-Nolan
Effects of volcanism on the glaciers of Mount St. Helens
The cataclysmic eruption of Mount St. Helens May 18, 1980, removed 2.9 km2 (about 0.13 km3) of glacier snow and ice including a large part of Shoestring, Forsyth, Wishbone, Ape, Nelson, and all of Loowit and Leschi Glaciers. Minor eruptions and bulging of the volcano from March 27 to May 17 shattered glaciers which were on the deforming rock and deposited ash on other glaciers. Thick ash layers pe
Authors
Melinda M. Brugman, Austin Post
Chronology of mudflows in the South Fork and North Fork Toutle River following the May 18 eruption
No abstract available.
Authors
J. E. Cummans
Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Hughes, Kotzebue, Melozitna, Selawik, and Shungnak quadrangles, west-central Alaska, supplement to Open-file report 75-627: Part B — Lists of refe
No abstract available.
Authors
Edward Huntington Cobb, Thomas P. Miller