Nature of magnetic grains in basalts and implications for palaeomagnetism
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778 C. Submarine Geology and Geophysics OLR(1979)26(I 2) 79:5984 Pearson, W. C. and C. R. B. Lister, 1979. The gravity signatures of isostatic, thermally-expanded ridge crests. Phys. Earth planet. Interiors, 19(1): 73-84. An accurate method of gravity computation is derived for isostatic, thermally-expanded spreading-center models. Results predict small positive anomalies over ridge crests which are then flanked by small negative anomalies beyond crossovers. Comparisons of theoretical predictions and observations of topography and gravity are presented. The value of gravity measurements in various geophysical studies is discussed. EDCON Inc., 345 S. Union, Lakewood, Colo. 80228, U.S.A. (rio) 79:5985 Radhakrishnamurty, C., S. D. Likhite, E. R. Deutsch and G. S. Murthy, 1978. Nature of magnetic grains in basaits and implications for palaeomag- netism. Proc. Indian Acad. Sci., 87(A)(Earth & Planetary Sci. 4(1 I): 235-243. A granulometric technique is employed in studying the temperature dependence of low-field susceptibility and low- and high-field hysteresis in 1042 basalt samples of widely varying ages; a predominant, cation- deficient phase of magnetite is often identified. Tata Institute of Fundamental Research, Bombay 400 005, India. (rio) 79:5986 Simpson, E. S. W., J. G. Sclater, B. Parsons, !. Nor- ton and L. Meinke, 1979. Mesozoic magnetic iin- cations in the Mozambique Basin. Earth planet. Sci. Letts, 43(2): 260-264. Mesozoic magnetic anomalies comprising the suite M2-M22 have an east-west orientation in the northern Mozambique Basin. The source of sea floor creation and a spreading rate of 1.5 cm/yr are inferred from the anomalies. The northward increase in age is consistent with a decreasing heat flow trend, and the overall results help to resolve the Gondwana configuration of the southern continents. Department of Oceanography, University of Cape Town, Rondebosch, South Africa. (rio) 79:5987 Somayajulu, B. k. K., C. Radhakrishnamurty and T. J. Walsh, 1978. Susceptibility as a tool for studying magnetic stratigraphy of marine sedi- ments. Proc. Indian Acad. Sci., 87(A)(Earth & Planetary Sci. 4)(1 I): 201-213. Eighty-six gravity cores from the Pacific Ocean have been categorized according to their magnetic susceptibility. Three basic types of cores have been described and a possible stratigraphic marker has been identified in the most common core type. Physical Research Laboratory, Ahmedabad 380 009, India. (rio) 79:5988 Wenzel, H.-G., 1978. Gravimetric vertical deflec- tion determination for the North Sea region (GVDNA 1). Dr. geod. Komrn., (B)235:24 pp. Gravimetric vertical deflections have been computed for the North Sea region in a grid with 0.25 ° spacing in latitude and 0.5 ° spacing in longitude. The accuracy of the computed deflections has been estimated to be better than +1" by comparison with astrogeodetic vertical deflections around the North Sea. Includes a full-size North Sea gravimetric vertical deflection map. 7. Historical geology (also see Biological Oceanography for fossil systematics) 79:5989 Badyukov, D. D., 1979. Sea level changes on the Soviet coasts of the White, Baltic and Black seas for the recent 15 thousand years. (In Russian: English abstract.) Okeanologiia, 19(2): 280-287. The level of the White Sea began to change synchronously with global ocean level changes about ll,000 vr B.P., and the Baltic Sea did so approximately 10,000 yr B.P,, but became separated from the ocean from 7600-4200 yr B.P.: glacio- isostatic and neotectonic movement complicated changes in the levels of both seas. The Black Sea level began to rise from 15,000-13,000 yr B.P. and may have exceeded its present level about 5000 yr B.P. (dine) 79:5990 Batchelor, B. C., 1979. Discontinuously rising Late Cainozoic eustatic sea-levels, with special refer- ence to Sundaland, Southeast Asia, Geologic Mijnb., 58(1): 1-20. A global rise in sea-level in the Late Cainozoic is suggested, in opposition to the view that sea-level was lowering at the time, and is based on the idea that the Sunda Platform has been a tectonically stable craton since the mid-Tertiary. Ca. 200 references. Depart- ment of Geology, University of Malaya, Kuala Lurn- put, Malaysia. (dme) 79:5991 Borisov, L. A., 1979. Recent vertical movements of the coasts of the USSR far-eastern seas based on sea-level changes for many years. (In Russian: English abstract.) Okeanologiia, 19(2): 288-292. The signs and magnitudes of sea-level change rates were quantified at 16 stations from 1947-1974. Anomalously high rates of sea-level rise were associated with coastal subsidence, while anomalous declines in sea level were attributed to coastal rise. (rlo)
Transcript of Nature of magnetic grains in basalts and implications for palaeomagnetism
778 C. Submarine Geology and Geophysics OLR(1979)26(I 2)
79:5984 Pearson, W. C. and C. R. B. Lister, 1979. The gravity
signatures of isostatic, thermally-expanded ridge crests. Phys. Earth planet. Interiors, 19(1 ): 73-84.
An accurate method of gravity computation is derived for isostatic, thermally-expanded spreading-center models. Results predict small positive anomalies over ridge crests which are then flanked by small negative anomalies beyond crossovers. Comparisons of theoretical predictions and observations of topography and gravity are presented. The value of gravity measurements in various geophysical studies is discussed. EDCON Inc., 345 S. Union, Lakewood, Colo. 80228, U.S.A. (rio)
79:5985 Radhakrishnamurty, C., S. D. Likhite, E. R. Deutsch
and G. S. Murthy, 1978. Nature of magnetic grains in basaits and implications for palaeomag- netism. Proc. Indian Acad. Sci., 87(A)(Earth & Planetary Sci. 4(1 I): 235-243.
A granulometric technique is employed in studying the temperature dependence of low-field susceptibility and low- and high-field hysteresis in 1042 basalt samples of widely varying ages; a predominant, cation- deficient phase of magnetite is often identified. Tata Institute of Fundamental Research, Bombay 400 005, India. (rio)
79:5986 Simpson, E. S. W., J. G. Sclater, B. Parsons, !. Nor-
ton and L. Meinke, 1979. Mesozoic magnetic iin- cations in the Mozambique Basin. Earth planet. Sci. Letts, 43(2): 260-264.
Mesozoic magnetic anomalies comprising the suite M2-M22 have an east-west orientation in the northern Mozambique Basin. The source of sea floor creation and a spreading rate of 1.5 cm/yr are inferred from the anomalies. The northward increase in age is consistent with a decreasing heat flow trend, and the overall results help to resolve the Gondwana configuration of the southern continents. Department of Oceanography, University of Cape Town, Rondebosch, South Africa. (rio)
79:5987 Somayajulu, B. k. K., C. Radhakrishnamurty and
T. J. Walsh, 1978. Susceptibility as a tool for studying magnetic stratigraphy of marine sedi- ments. Proc. Indian Acad. Sci., 87(A)(Earth & Planetary Sci. 4)(1 I): 201-213.
Eighty-six gravity cores from the Pacific Ocean have been categorized according to their magnetic susceptibility. Three basic types of cores have been described and a possible stratigraphic marker has been identified in the most common core type. Physical Research Laboratory, Ahmedabad 380 009, India. (rio)
79:5988 Wenzel, H.-G., 1978. Gravimetric vertical deflec-
tion determination for the North Sea region (GVDNA 1). Dr. geod. Komrn., (B)235:24 pp.
Gravimetric vertical deflections have been computed for the North Sea region in a grid with 0.25 ° spacing in latitude and 0.5 ° spacing in longitude. The accuracy of the computed deflections has been estimated to be better than +1" by comparison with astrogeodetic vertical deflections around the North Sea. Includes a full-size North Sea gravimetric vertical deflection map.
7. Historical geology (also see Biological Oceanography for fossil systematics)
79:5989 Badyukov, D. D., 1979. Sea level changes on the
Soviet coasts of the White, Baltic and Black seas for the recent 15 thousand years. (In Russian: English abstract.) Okeanologiia, 19(2): 280-287.
The level of the White Sea began to change synchronously with global ocean level changes about ll,000 vr B.P., and the Baltic Sea did so approximately 10,000 yr B.P,, but became separated from the ocean from 7600-4200 yr B.P.: glacio- isostatic and neotectonic movement complicated changes in the levels of both seas. The Black Sea level began to rise from 15,000-13,000 yr B.P. and may have exceeded its present level about 5000 yr B.P. (dine)
79:5990 Batchelor, B. C., 1979. Discontinuously rising Late
Cainozoic eustatic sea-levels, with special refer- ence to Sundaland, Southeast Asia, Geologic Mijnb., 58(1): 1-20.
A global rise in sea-level in the Late Cainozoic is suggested, in opposition to the view that sea-level was lowering at the time, and is based on the idea that the Sunda Platform has been a tectonically stable craton since the mid-Tertiary. Ca. 200 references. Depart- ment of Geology, University of Malaya, Kuala Lurn- put, Malaysia. (dme)
79:5991 Borisov, L. A., 1979. Recent vertical movements of
the coasts of the USSR far-eastern seas based on sea-level changes for many years. (In Russian: English abstract.) Okeanologiia, 19(2): 288-292.
The signs and magnitudes of sea-level change rates were quantified at 16 stations from 1947-1974. Anomalously high rates of sea-level rise were associated with coastal subsidence, while anomalous declines in sea level were attributed to coastal rise. (rlo)
