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Age and correlation of California Paleogene benthic foraminiferal stages
OLR(1980)27(12)
C. Submarine Geology and Geophysics
with the coastal regime. Includes 1 aerial photo. Department of Agronomy, University of Georgia, Athens, Ga. 30602, U.S.A. (kmk) 80:5896 O'Keefe, J. A., 1980. The terminal Eocene event: formation of a ring system around the E a r t h ? Nature, Lond., 285(5763): 309-311. A theory is proposed which explains the correlation between the approximately synchronous major climate change and the largest tektite-strewn field, or shower, 34 m.y. ago. A tektite shower of cosmic origin would influence climate by forming an equatorial ring of trapped particles that would reduce sunlight by about 75%, producing a 20C ° temperature drop in the winter but not in the summer. A ring lifetime of a few million years would be expected on the basis of physical effects acting to disperse it. Laboratory for Astronomy and Solar Physics, Goddard Space Flight Center, Greenbelt, Md. 20771, U.S.A. (has)
80:5897 Poore, R. Z., 1980. Age and correlation of California Paleogene benthic foramlntferal stages. Prof. Pap. U.S. geol. Surv., 1162-C: 8 pp. Age ranges of benthic foraminiferal assemblages correlated with calcareous plankton have been determined as part of a project developing an interrelated set of biostratigraphic zonations. As significant time overlap was found for the Ynezian through Ulatisian stages, interbasin correlations must be treated carefully. The Nazirian-Refugian boundary was defined within the Upper Eocene, and Zemorrian correlates with the Oligocene ( p o s s i b l y to Lower M i o c e n e ) . I n c l u d e s stratigraphic tables. (kmk)
80:5898 Prell, W. L. and J.V. Gardner (co-chief scientists), 1980. Hydraulic piston coring of Late Neogene and Q u a t e r n a r y sections in the C a r i b b e a n and e q u a t o r i a l Pacific: preliminary results of Deep Sea Drilling Project leg 68. Bull. geol. Soc. Am., 91(7)(I): 433-444. Recovered with the newly developed Hydraulic Piston Corer, undisturbed sections from the Caribbean (site 502) and the Pacific (site 503) provided continuous data from the Brunhes-Matuyama through the Gilbert paleomagnetic boundaries. The magnetostratigraphy and biostratigraphy resulted in detailed, high resolution Neogene and Quaternary stratigraphy that can be applied to paleoclimatic and paleoceanographic studies such as the closing of the Isthmus of Panama and glaciation initiation in the Northern Hemisphere.
865
Includes stratigraphic tables. Department of Geological Sciences, Brown University, Providence, R.I. 02912, U.S.A. (kink) 80:5899 Rawls, R. L., 1980. Iridium provides clue to dinosaurs' extinction. Chem. Engng News, 58(25): 40-45. Three recent, closely-related theories explaining the mass extinctions at the end of the Cretaceous are reviewed: (1) Alverez et al., asteroid collision; (2)Smit and Hertogen, meteorite collision; (3) Hsu, comet collision. All three propose an extraterrestrial source for the elevated iridium concentrations found in Cretaceous/Tertiary boundary clay sediments in Italy, Denmark, New Zealand and southeastern Spain. (izs)
80:5900 Stanley, D. J. and Christian Blanpied, 1980. Late Quaternary water exchange between the Mediterranean and the Black Sea. Nature, Lond., 285(5766): 537-541. Sea of Marmara sediments provide an almost complete record of major palaeoceanographic events affecting the Aegean and Black seas between the Late Pleistocene and the Recent. Fluctuating patterns of water mass exchange, resulting from regionally i m p o r t a n t climatic oscillations, produced the marked differences in lithofacies mapped between the Sea of Marmara and the eastern Mediterranean and Black seas. Division of Sedimentology, Smithsonian Institution, Washington, D.C. 20560, U.S.A.
80:5901 Von Huene, Roland and Jean Aubouin (co-chief scientists), 1980. Leg 67: the Deep Sea Drilling Project Mid-America Trench transect off Guatemala. Bull. geol. Soc. Am., 1(7) (I): 421-432. Drill cores obtained from the Mid-America Trench transect off Guatemala, conducted by the DSDP 'to study a convergent margin where accretion and imbrication may have been continuous during most of Tertiary time,' revealed a Miocene basal chalk sequence, abyssal red clay, and Late Miocene and younger sediments on the oceanic Cocos Plate; there was no evidence of compressive deformation. Cores taken 3 km from the trench axis i n c l u d e d d i s c o n t i n u o u s s e c t i o n s of Cretaceous-Pliocene claystone overlain by Pliocene-Quaternary hemipelagic slope deposits. The presence of Cretaceous-Miocene mudstone at the base of the trench slope seems inconsistent with currently accepted models for convergent
C. Submarine Geology and Geophysics
with the coastal regime. Includes 1 aerial photo. Department of Agronomy, University of Georgia, Athens, Ga. 30602, U.S.A. (kmk) 80:5896 O'Keefe, J. A., 1980. The terminal Eocene event: formation of a ring system around the E a r t h ? Nature, Lond., 285(5763): 309-311. A theory is proposed which explains the correlation between the approximately synchronous major climate change and the largest tektite-strewn field, or shower, 34 m.y. ago. A tektite shower of cosmic origin would influence climate by forming an equatorial ring of trapped particles that would reduce sunlight by about 75%, producing a 20C ° temperature drop in the winter but not in the summer. A ring lifetime of a few million years would be expected on the basis of physical effects acting to disperse it. Laboratory for Astronomy and Solar Physics, Goddard Space Flight Center, Greenbelt, Md. 20771, U.S.A. (has)
80:5897 Poore, R. Z., 1980. Age and correlation of California Paleogene benthic foramlntferal stages. Prof. Pap. U.S. geol. Surv., 1162-C: 8 pp. Age ranges of benthic foraminiferal assemblages correlated with calcareous plankton have been determined as part of a project developing an interrelated set of biostratigraphic zonations. As significant time overlap was found for the Ynezian through Ulatisian stages, interbasin correlations must be treated carefully. The Nazirian-Refugian boundary was defined within the Upper Eocene, and Zemorrian correlates with the Oligocene ( p o s s i b l y to Lower M i o c e n e ) . I n c l u d e s stratigraphic tables. (kmk)
80:5898 Prell, W. L. and J.V. Gardner (co-chief scientists), 1980. Hydraulic piston coring of Late Neogene and Q u a t e r n a r y sections in the C a r i b b e a n and e q u a t o r i a l Pacific: preliminary results of Deep Sea Drilling Project leg 68. Bull. geol. Soc. Am., 91(7)(I): 433-444. Recovered with the newly developed Hydraulic Piston Corer, undisturbed sections from the Caribbean (site 502) and the Pacific (site 503) provided continuous data from the Brunhes-Matuyama through the Gilbert paleomagnetic boundaries. The magnetostratigraphy and biostratigraphy resulted in detailed, high resolution Neogene and Quaternary stratigraphy that can be applied to paleoclimatic and paleoceanographic studies such as the closing of the Isthmus of Panama and glaciation initiation in the Northern Hemisphere.
865
Includes stratigraphic tables. Department of Geological Sciences, Brown University, Providence, R.I. 02912, U.S.A. (kink) 80:5899 Rawls, R. L., 1980. Iridium provides clue to dinosaurs' extinction. Chem. Engng News, 58(25): 40-45. Three recent, closely-related theories explaining the mass extinctions at the end of the Cretaceous are reviewed: (1) Alverez et al., asteroid collision; (2)Smit and Hertogen, meteorite collision; (3) Hsu, comet collision. All three propose an extraterrestrial source for the elevated iridium concentrations found in Cretaceous/Tertiary boundary clay sediments in Italy, Denmark, New Zealand and southeastern Spain. (izs)
80:5900 Stanley, D. J. and Christian Blanpied, 1980. Late Quaternary water exchange between the Mediterranean and the Black Sea. Nature, Lond., 285(5766): 537-541. Sea of Marmara sediments provide an almost complete record of major palaeoceanographic events affecting the Aegean and Black seas between the Late Pleistocene and the Recent. Fluctuating patterns of water mass exchange, resulting from regionally i m p o r t a n t climatic oscillations, produced the marked differences in lithofacies mapped between the Sea of Marmara and the eastern Mediterranean and Black seas. Division of Sedimentology, Smithsonian Institution, Washington, D.C. 20560, U.S.A.
80:5901 Von Huene, Roland and Jean Aubouin (co-chief scientists), 1980. Leg 67: the Deep Sea Drilling Project Mid-America Trench transect off Guatemala. Bull. geol. Soc. Am., 1(7) (I): 421-432. Drill cores obtained from the Mid-America Trench transect off Guatemala, conducted by the DSDP 'to study a convergent margin where accretion and imbrication may have been continuous during most of Tertiary time,' revealed a Miocene basal chalk sequence, abyssal red clay, and Late Miocene and younger sediments on the oceanic Cocos Plate; there was no evidence of compressive deformation. Cores taken 3 km from the trench axis i n c l u d e d d i s c o n t i n u o u s s e c t i o n s of Cretaceous-Pliocene claystone overlain by Pliocene-Quaternary hemipelagic slope deposits. The presence of Cretaceous-Miocene mudstone at the base of the trench slope seems inconsistent with currently accepted models for convergent