Publications
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Compositional zonation and cumulus processes in the Mount Mazama magma chamber, Crater Lake, Oregon
The 6845 ± 50 BP climactic eruption of Mount Mazama discharged 47 ± 9 km3 of vertically zoned calc-alkaline magma, affording a virtually complete section through the chamber. Evidence for two andesitic parents with different trace-element (particularly Sr) and water contents is preserved in the ejecta. Prior to eruption, a dominant volume of rhyodacite was underlain successively by high-Sr andesit
Authors
T. H. Druitt, Charles R. Bacon
Voluminous submarine lava flows from Hawaiian volcanoes
The GLORIA long-range sonar imaging system has revealed fields of large lava flows in the Hawaiian Trough east and south of Hawaii in water as deep as 5.5 km. Flows in the most extensive field (110 km long) have erupted from the deep submarine segment of Kilauea's east rift zone. Other flows have been erupted from Loihi and Mauna Loa. This discovery confirms a suspicion, long held from subaerial s
Authors
Robin T. Holcomb, James G. Moore, Peter W. Lipman, R.H. Belderson
Large-scale bedforms in boulder gravel produced by giant waves in Hawaii
Approximately 105,000 yr ago (based on uranium-series dating), waves in a giant wave train swept up to an elevation of about 375 m on the island of Lanai. The waves deposited the Hulopoe Gravel, which near the present shoreline consists of basalt boulders, coral fragments, and calcareous beachrock slabs, and near the upper limit of the deposit consists of sand and shell fragments. The maximum heig
Authors
G. W. Moore, James G. Moore
The Mount Mazama climactic eruption (6900 BP) and resulting convulsive sedimentation on the continent, ocean basin, and Crater Lake caldera floor
The climactic eruption of Mount Mazama and the resulting sedimentation may have been the most significant convulsive sedimentary event in North America during Holocene time. A collapse caldera 1,200 m deep and 10 km in diameter was formed in Mount Mazama, and its floor was covered by hundreds of meters of wall-collapse debris. Wind-blown pyroclastic ash extended 2,000 km northeast from Mount Mazam
Authors
C. Hans Nelson, Paul R. Carlson, Charles R. Bacon
Mg/Mn partitioning as a test for equilibrium between coexisting Fe-Ti oxides
Partitioning of Mg and Mn between titanomagnetite and ferrian ilmenite of volcanic rocks provides a test for equilibrium between coexisting phases. A plot of log(Mg/Mn)-, vs. log(Mg/Mn),, for 213 homogeneous oxide pairs from volcanic rocks yields a straight line over more than two orders of magnitude variation in Mg/Mn. Analyses that plot within reasonable limits of analytical precision of this li
Authors
Charles R. Bacon, M.M. Hirschmann
Hydrologic data for computation of sediment discharge: Toutle and North Fork Toutle Rivers near Mount St. Helens, Washington, water years 1980-84
Immediately after the devastating May 18, 1980, eruption of Mount St. Helens, a program was initiated by the U.S. Geological Survey to study the streamflow and sediment characteristics of streams impacted by the eruption. Some of the data gathered in that program are presented in this report. Data are presented for two key sites in the Toutle River basin: North Fork Toutle River near Kid Valley, a
Authors
Dallas Childers, Stephen E. Hammond, William P. Johnson
Diskette version of analytical results, and sample locality map for rock samples from the Iditarod quadrangle, Alaska
No abstract available.
Authors
Robert G. McGimsey, Marti L. Miller, B. F. Arbogast
Teaching aids in seismology
No abstract available.
QED
No abstract available.
Communications award goes to earthquake expert
No abstract available.