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Geophysical observations of Kilauea Volcano, Hawaii. II. Constraints on the magma supply during November 1975–September 1977
OLR(1980)27(12)
C. Submarine Geology and Geophysics
Contrary to the usual method of defining oceanic magnetic layers according to mode of emplacement or lithology, measurements on basalt samples from the Troodos suggest the greatest changes occur at the zeolite-greenschist metamorphic boundary. Remanent intensity, susceptibility, thermomagnetic and magnetic mineralogy, X-ray and electron microprobe studies support this theory by indicating a sharp decrease in the Koenigsberger ratio and a change of the dominant mineral from titanomagnetite to magnetite at the boundary. These results could greatly affect modeling of marine magnetic anomalies. D e p a r t m e n t of Geology and Geological Engineering, Michigan Technological University, Houghton, Mich. 49931, U.S.A. (bas) 80:5920 Crosson, R. S. et al., 1980. Eruption of Mt. St. Helens. Nature, Lond., 285(5766): 529-535; 3 reports. Mt. St. Helens erupted explosively on May 18, 1980, removing several km 3 of material from the top of the mountain, and destroying about 400 km 2 by deforestation, tephra fallout, and mud and pyroclastic flows. As eruptions go, it was a powerful one on a time scale of about a century. Presented here are three preliminary scientific reports. Seismic activity preceded the explosion by two months, and its patterns suggest some potential for hazard forecasting. At present little can be said about climatological effects, except that they are being monitored. Mr. St. Helens' past symmetry, and that of other Cascade Range volcanoes, suggest that new magma may yet reach the surface. And the volcanologists may be kept busy: when Mt. St. Helens erupted in 1842, eruptions of Rainier, Baker and Hood followed within thirteen years. (fcs) 80:5921 Davies, H. L. et al., 1980. Ophiolites and related rocks. Am. J. Sci., 280-A(1): 171-388; 10 papers. Washington, Oregon, California, Greece, PapuaNew Guinea and' New Zealand are the sites for these largely petrological and geochemical studies. One paper is concerned with the general interpretation of peridotite structures, another with syncrystallization and subsolidus deformation in gabbros and ophiolitic peridotites. (fcs) 80:5922 Dmitriyev, L. V., A. V. Sobolev and N. M. S u s h c h e v s k a y a , 1979. P r i m a r y - m a g m a production and composition variations for oceanic tholeiites. Geochern. int. (a translation of Geokhimiya), 16(1): 80-94.
869
A petrologic model was developed from petrochemical and geochemical studies to explain compositional variations in oceanic layer 2 in the Atlantic. Oceanic basalts are derived from a primary tholeiiticmagma, produced from dry lherzolite mantle at depths of 15-40 kin. Compositional variations in the basalt are related to the depth of m a g m a formation and extent of m a g m a differentiation. Includes olivine inclusion micrographs. Vernadskiy Institute of Geochemistry and Analytical Chemistry, Academy of Sciences of the U.S.S.R., Moscow, U.S.S.R. (kink) 80:5923 Dzurisin, Daniel et al., 1980. Geophysical observations of Kilauea Volcano, Hawaii. II. Constraints on the m a g m a supply during November 1975-September 1977. J. Volcanol. geotherm. Res., 7(3/4): 241-269. Magma supply to Kilauea was modeled based on seismic, geodetic, gravimetric, and electrical selfpotential observations. The September 1977 eruption was preceded by 5 episodes of rapid summit deflation (atypical for Kilauea), suggesting magma migration from the summit to the east rift zone. Tiltmeter observations and the high number of microearthquakes (200-400 per day) suggest future eruptions in the east rift zone. U.S. Geological Survey, Hawaiian Volcano Ob~rvatory, Hawaii National Park, Hawaii 96718, U.S.A. (kink) 80:5924 Fornari, D. J., J. P. Lockwood, P. W. Lipman, Michael Rawson and Alexander Malahoff, 1980. Submarine volcanic features west of Kealakekua Bay, Hawaii. J. Volcanol. geotherm. Res., 7(3/4): 323-337. Submarine volcanic vents, west of Kealakekua Bay, were observed on 15 dives of the U.S. Navy submersible Sea Cliff. Two eruptive events, one from subaqueous vents and the other having a subaerial origin, were identified in the young volcanic terrain of the seafioor. Chemical analyses of samples taken near the vents indicate compositions similar to products of historical Mauna Loa eruptions. Includes seismic profiles and 18 bottom photos. Department of Geological Sciences, State University of New York at Albany, Albany, N.Y. 12222, U.S.A. (kink) 80:5925 Gerlach, T. M., 1980. Evaluation of volcanic gas analyses from Kilauea Volcano. J. Volcanol. geotherrn. Res., 7(3/4): 295-317. Several widely quoted analyses of gas collections from Kilauea (in particular, Jagger's J-Series of 1918) signal extreme chemical variation and disequilibrium. It is determined that contamination
C. Submarine Geology and Geophysics
Contrary to the usual method of defining oceanic magnetic layers according to mode of emplacement or lithology, measurements on basalt samples from the Troodos suggest the greatest changes occur at the zeolite-greenschist metamorphic boundary. Remanent intensity, susceptibility, thermomagnetic and magnetic mineralogy, X-ray and electron microprobe studies support this theory by indicating a sharp decrease in the Koenigsberger ratio and a change of the dominant mineral from titanomagnetite to magnetite at the boundary. These results could greatly affect modeling of marine magnetic anomalies. D e p a r t m e n t of Geology and Geological Engineering, Michigan Technological University, Houghton, Mich. 49931, U.S.A. (bas) 80:5920 Crosson, R. S. et al., 1980. Eruption of Mt. St. Helens. Nature, Lond., 285(5766): 529-535; 3 reports. Mt. St. Helens erupted explosively on May 18, 1980, removing several km 3 of material from the top of the mountain, and destroying about 400 km 2 by deforestation, tephra fallout, and mud and pyroclastic flows. As eruptions go, it was a powerful one on a time scale of about a century. Presented here are three preliminary scientific reports. Seismic activity preceded the explosion by two months, and its patterns suggest some potential for hazard forecasting. At present little can be said about climatological effects, except that they are being monitored. Mr. St. Helens' past symmetry, and that of other Cascade Range volcanoes, suggest that new magma may yet reach the surface. And the volcanologists may be kept busy: when Mt. St. Helens erupted in 1842, eruptions of Rainier, Baker and Hood followed within thirteen years. (fcs) 80:5921 Davies, H. L. et al., 1980. Ophiolites and related rocks. Am. J. Sci., 280-A(1): 171-388; 10 papers. Washington, Oregon, California, Greece, PapuaNew Guinea and' New Zealand are the sites for these largely petrological and geochemical studies. One paper is concerned with the general interpretation of peridotite structures, another with syncrystallization and subsolidus deformation in gabbros and ophiolitic peridotites. (fcs) 80:5922 Dmitriyev, L. V., A. V. Sobolev and N. M. S u s h c h e v s k a y a , 1979. P r i m a r y - m a g m a production and composition variations for oceanic tholeiites. Geochern. int. (a translation of Geokhimiya), 16(1): 80-94.
869
A petrologic model was developed from petrochemical and geochemical studies to explain compositional variations in oceanic layer 2 in the Atlantic. Oceanic basalts are derived from a primary tholeiiticmagma, produced from dry lherzolite mantle at depths of 15-40 kin. Compositional variations in the basalt are related to the depth of m a g m a formation and extent of m a g m a differentiation. Includes olivine inclusion micrographs. Vernadskiy Institute of Geochemistry and Analytical Chemistry, Academy of Sciences of the U.S.S.R., Moscow, U.S.S.R. (kink) 80:5923 Dzurisin, Daniel et al., 1980. Geophysical observations of Kilauea Volcano, Hawaii. II. Constraints on the m a g m a supply during November 1975-September 1977. J. Volcanol. geotherm. Res., 7(3/4): 241-269. Magma supply to Kilauea was modeled based on seismic, geodetic, gravimetric, and electrical selfpotential observations. The September 1977 eruption was preceded by 5 episodes of rapid summit deflation (atypical for Kilauea), suggesting magma migration from the summit to the east rift zone. Tiltmeter observations and the high number of microearthquakes (200-400 per day) suggest future eruptions in the east rift zone. U.S. Geological Survey, Hawaiian Volcano Ob~rvatory, Hawaii National Park, Hawaii 96718, U.S.A. (kink) 80:5924 Fornari, D. J., J. P. Lockwood, P. W. Lipman, Michael Rawson and Alexander Malahoff, 1980. Submarine volcanic features west of Kealakekua Bay, Hawaii. J. Volcanol. geotherm. Res., 7(3/4): 323-337. Submarine volcanic vents, west of Kealakekua Bay, were observed on 15 dives of the U.S. Navy submersible Sea Cliff. Two eruptive events, one from subaqueous vents and the other having a subaerial origin, were identified in the young volcanic terrain of the seafioor. Chemical analyses of samples taken near the vents indicate compositions similar to products of historical Mauna Loa eruptions. Includes seismic profiles and 18 bottom photos. Department of Geological Sciences, State University of New York at Albany, Albany, N.Y. 12222, U.S.A. (kink) 80:5925 Gerlach, T. M., 1980. Evaluation of volcanic gas analyses from Kilauea Volcano. J. Volcanol. geotherrn. Res., 7(3/4): 295-317. Several widely quoted analyses of gas collections from Kilauea (in particular, Jagger's J-Series of 1918) signal extreme chemical variation and disequilibrium. It is determined that contamination