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Carbon and oxygen isotope composition of Globigerinoides ruber in two deep-sea cores from the Levantine Basin (eastern Mediterranean)
1054
D. Submarine Geology and Geophysics
differences between the populations, such as growth rate and lobateness of the test, reflect changes in temperature as derived from palynological evidence. Results demonstrate that morphological changes in planktonic Foraminifera may be directly related to specific paleoecologic parameters rather than undefined environmental stress. Geomar. Center Amsterdam, Free Univ., P.O. Box 7161, 1007 MC Amsterdam, Netherlands.
87:6902 Bishop, G.A., 1986. Occurrence, preservation, and blegeogra~y of the Cretaceous crabs of North America. Crustacean Issues, 4:111-142. The Cretaceous record of brachyuran and anomuran decapod crustaceans is reviewed for the northern Atlantic and Gulf coastal plains, U.S. Western Interior and Pacific Slope regions. Regional comparisons are made and possible mechanisms giving rise to faunistic differences are discussed. Dept. of Geol. and Geogr., Georgia Southern Coll., Statesboro, GA, USA. (gsb)
87:6903 BjOrklund, K.R. and Rudolf De Rulter, 1987. Radlelari~ lWWefvatlon in eastern Meditorra. helm onoxk secJbJeats. Mar. Geol., 75(1-4):271281. Anoxic sediments from the Tyro and Kretheus basins contain an excellently preserved radiolarian fauna. This paper illustrates 75 polycystine and 2 phaeodarian radiolarian species from a total number of approximately 200 species. Good opal preservation in these sediments seems to be primarily caused by the high silica level of the brine water. Paleontolog. Mus., Univ. of Oslo, Sarsgate 1, 0562 Oslo 5, Norway.
87:6904 Brand, U., J.O. Morrison, N. Brand and E. Brand, 1987. ~ vmtiion in dRe Jells of recent mmtae I n v ~ from ti~ ~ Padfle Chem. Geol, 65(2):137-145. Water temperatures calculated from organisms incorporating C and O into shell carbonate in isotopic equilibrium with ambient seawater indicate that Ba/anus preferentially precipitates calcite during cooler months, Diadora throughout the year, and Mytilus and Cailiastoma during warmer months. Dept. of Geolog. Sci., Brock Univ., St. Catharines, ON L2S 3AI, Canada.
OLR (1987) 34 (12)
87:6905 Feldmann, R.M., 1986. Ptleobioli~0gra~y of two decalmd ¢rmtaeeon taxa In the Southern Hemi. sphere: global ~ with sparse data. Crustacean Issues, 4:5-20. Despite limited fossil data, conclusions are reached about the dispersal of the Aeglidae and the raninid genus Lyreidus that are similar to patterns discerned in Wedellian Province mollusks. Dispersal into lower latitudes during the Early Oligocene is suggested, following a Late Cretaceous/Eocene southern circum-Pacific origin. Continued dispersal appears to have been inhibited by the break-up of the southern Pacific landmass and the appearance of the circumAntarctic current system. Dept. of Geol., Kent State Univ., Kent, OH, USA. (gsb) 87:6906 Hald, Morten and T.O. Vorren, 1987. Foraminiferal stra~y and eavironment of Late Wekhsellan on the continont~ shelf off Troms, Norway. Mar. Micropaleont., 12(2): 129-160. Univ. of Tromso, Inst. of Biol. and Geol., P.O. Box 3085, Guleng, N-9001 Tromso, Norway.
87:6907 Loubere, Paul and Gwen Banonis, 1987. Benthic formli~lmd ~ rUl~me to the omet of N ~ ~ gbdltflOL Paleoenvironmental changes and species trends in the northeast Atlantic. Mar. Micropaleont., 12(2): 161-181. Factor analysis of species abundance data from closely spaced samples from DSDP-IPOD Site 548 shows that replacement of a Glo&~assidulina subglobosa assemblage by Bulimina mexicana and then by Melonis-Uvigerina assemblages and greater assemblage variability accompanied the onset of glaciation. Canonical correlation analysis of species data and independent paleoenvironmental indicators show a strong relationship between planktonic assemblage diversity and long-term benthic trends which could be a response to changing bottom water properties or increasing food supply. The assemblages also show a strong relationship to changes in sediment carbonate content. However, a significant fraction of variability cannot be explained by the paleoenvironmental indicators used in this study. Dept. of Geol., Northern Illinois Univ., DeKalb, IL 60115, USA. 87:6908 Nigam, Rajiv and A.S. Rao, 1987. Prolocuim size vorlatlea in r e c u t bemtl~ FemainUera: impUcatlom for ~ sta~es. Estuar. coast. Shelf Sci., 24(5):649-655.
OLR (1987)34(12)
D. SubmarineGeologyand Geophysics
Ratios of dimorphic (microspheric/megalospheric) forms of Foraminifera are affected by temperature and hence are useful in paleoclimatic studies. In some cases, however, it is not possible to distinguish between the dimorphic forms and, therefore, mean proloculus size is useful. The mean proloculus size of Cavarotalia annectens was measured in 14 surface sediment samples from the near-shore region along the west coast of India (Bombay to Kannyakumari). The results show that mean proloculus size varies from 0.045 to 0.103 ram, and is inversely proportional to temperature and salinity variations. It is proposed, therefore, that mean proloculns size of Foraminifera can be used as an additional tool in paleoclimatic studies. Natl. Inst. of Oceanogr., Dona Paula, Goa 403 004, India. 87:6909 Oggioni, Elisabetta and Liliana Zandini, 1987. Response of benthic Foraminifera to stagnant episodes. A quantitative study of Core BAN 81-23, eastern Mediterranean. Mar. Geol., 75(14):241-261.
Changes in benthic foraminiferal faunas found in a core from the Ares Crater (western Mediterranean Ridge), which included seven sapropel and two tephra layers ranging in age from 5000 to 250,000 yrBP, are described and compared with changes across sapropels $6 through $3 in cores from the nearby Poseidon Plateau (Schilling, 1986). The study shows that a marked reduction in faunal density accompanied the cyclically repeated episodes of stagnation. A consistent sparse faunule of shallowwater epiphytic rotaliforms, probably transported by floating algae and Bolivina spp. and buliminids capable of tolerating very low oxygen levels, was found within the sapropels. Unlike the other layers, the top of sapropel $6 originated under glacial conditions and was preceded by peak abundances of faunal density. Dept. of Earth Sei., Univ. of Milan, Via Manglagalli 34, 20133 Milan, Italy. (hbf) 87:6910 Parisi, Elisabetta, 1987. Carbon and oxygen isotope comlmsition of G/ob~r/ao/des tuber in two deep-sea cores from the Levantine Basin (eastern Mediterrsnean). Mar. Geol., 75(1-4):201-219.
Carbon and oxygen isotope analyses were carried out on 114 samples of G. tuber from two deep-sea cores from the outer slopes of the Mediterranean Ridge. These cores contain the sedimentary history of the eastern Mediterranean in the last 300,000 yr and include sapropelitic layers Ss to S~0. Climatic fluctuations recorded by the isotopic signal correlate well with previous studies; most sapropelitic intervals correspond to warm climatic conditions. Only S6
1055
and partially Ss reflect glacial conditions, indicating an alternative model for the deposition of organicrich layers. The magnitude of fluctuations in oxygen isotope composition (about 7 ppt) is unusually wide for the eastern Mediterranean, and the record is generally shifted toward negative values for approximately 1 ppt, probably due to the Nile discharge. Oxygen and carbon curves are in phase showing the large influence of organic productivity on carbon isotope composition. Dept. of Earth Sei., Univ. of Milan, Via Mangiagalli 34, 20133, Milan, Italy. 87:6911 Patterson, R.T. and R.H. Richardson, 1987. A taxonomic revision of the ~ Forsminffera. J.foram. Res~ 17(3):212-226. Dept. of Earth and Space Sei., Univ. of Calif., Los Angeles, CA 90O24, USA. 87:6912 Por, F.D., 1986. Crustacean ~ of the Late Middle Miocene Middle Eastern landbHdge. Crustacean Issues, 4:69-84.
The low diversity crustacean fauna of the Levantine Basin reflects the influence of several dramatic changes in the region, including the establishment of the Middle Eastern landbridge (dividing the circumtropical Tethys Ocean), a subsequent period of drying, the 'Messinian Salinity Crisis' during which the basin contained only hypersaline lakes and species richness was greatly diminished, the influx of oceanic waters through Gibraltar, a series of Pleistocene cold periods, and cyclical wet and dry periods affecting the surrounding arid lands. The fauna of the Red and Mediterranean seas are compared and the impact of the Suez Canal is examined. Dept. of Zool., Hebrew Univ., Jerusalem, Israel. (gsb) 87:6913 Stabell, Bjerg, 1987. Changes in diatom floras in Late Qummmry wesm'u and southeastern N e ~ i a n marine and f n ~ h ~ ~ m ~ Response to basin isolation from the sea. Nova Hedwigia, 44(3-4):305-326. Dept. of Geol., Univ. of Oslo, P.O. Box 1047, Blindern, N-0316 Oslo 3, Norway. 87:6914 Van Harten, Dick, 1987. Oslrscedes and the Early Holoeene anoxk event in the eastern M e ~ e r ra~an-.-evidanee and ~ Mar. Geol~
75(I-4):263-269. Several species of deep-water ostracodes still common in the western Mediterranean became extinct in the eastern Mediterranean Basin at the onset of early
D. Submarine Geology and Geophysics
differences between the populations, such as growth rate and lobateness of the test, reflect changes in temperature as derived from palynological evidence. Results demonstrate that morphological changes in planktonic Foraminifera may be directly related to specific paleoecologic parameters rather than undefined environmental stress. Geomar. Center Amsterdam, Free Univ., P.O. Box 7161, 1007 MC Amsterdam, Netherlands.
87:6902 Bishop, G.A., 1986. Occurrence, preservation, and blegeogra~y of the Cretaceous crabs of North America. Crustacean Issues, 4:111-142. The Cretaceous record of brachyuran and anomuran decapod crustaceans is reviewed for the northern Atlantic and Gulf coastal plains, U.S. Western Interior and Pacific Slope regions. Regional comparisons are made and possible mechanisms giving rise to faunistic differences are discussed. Dept. of Geol. and Geogr., Georgia Southern Coll., Statesboro, GA, USA. (gsb)
87:6903 BjOrklund, K.R. and Rudolf De Rulter, 1987. Radlelari~ lWWefvatlon in eastern Meditorra. helm onoxk secJbJeats. Mar. Geol., 75(1-4):271281. Anoxic sediments from the Tyro and Kretheus basins contain an excellently preserved radiolarian fauna. This paper illustrates 75 polycystine and 2 phaeodarian radiolarian species from a total number of approximately 200 species. Good opal preservation in these sediments seems to be primarily caused by the high silica level of the brine water. Paleontolog. Mus., Univ. of Oslo, Sarsgate 1, 0562 Oslo 5, Norway.
87:6904 Brand, U., J.O. Morrison, N. Brand and E. Brand, 1987. ~ vmtiion in dRe Jells of recent mmtae I n v ~ from ti~ ~ Padfle Chem. Geol, 65(2):137-145. Water temperatures calculated from organisms incorporating C and O into shell carbonate in isotopic equilibrium with ambient seawater indicate that Ba/anus preferentially precipitates calcite during cooler months, Diadora throughout the year, and Mytilus and Cailiastoma during warmer months. Dept. of Geolog. Sci., Brock Univ., St. Catharines, ON L2S 3AI, Canada.
OLR (1987) 34 (12)
87:6905 Feldmann, R.M., 1986. Ptleobioli~0gra~y of two decalmd ¢rmtaeeon taxa In the Southern Hemi. sphere: global ~ with sparse data. Crustacean Issues, 4:5-20. Despite limited fossil data, conclusions are reached about the dispersal of the Aeglidae and the raninid genus Lyreidus that are similar to patterns discerned in Wedellian Province mollusks. Dispersal into lower latitudes during the Early Oligocene is suggested, following a Late Cretaceous/Eocene southern circum-Pacific origin. Continued dispersal appears to have been inhibited by the break-up of the southern Pacific landmass and the appearance of the circumAntarctic current system. Dept. of Geol., Kent State Univ., Kent, OH, USA. (gsb) 87:6906 Hald, Morten and T.O. Vorren, 1987. Foraminiferal stra~y and eavironment of Late Wekhsellan on the continont~ shelf off Troms, Norway. Mar. Micropaleont., 12(2): 129-160. Univ. of Tromso, Inst. of Biol. and Geol., P.O. Box 3085, Guleng, N-9001 Tromso, Norway.
87:6907 Loubere, Paul and Gwen Banonis, 1987. Benthic formli~lmd ~ rUl~me to the omet of N ~ ~ gbdltflOL Paleoenvironmental changes and species trends in the northeast Atlantic. Mar. Micropaleont., 12(2): 161-181. Factor analysis of species abundance data from closely spaced samples from DSDP-IPOD Site 548 shows that replacement of a Glo&~assidulina subglobosa assemblage by Bulimina mexicana and then by Melonis-Uvigerina assemblages and greater assemblage variability accompanied the onset of glaciation. Canonical correlation analysis of species data and independent paleoenvironmental indicators show a strong relationship between planktonic assemblage diversity and long-term benthic trends which could be a response to changing bottom water properties or increasing food supply. The assemblages also show a strong relationship to changes in sediment carbonate content. However, a significant fraction of variability cannot be explained by the paleoenvironmental indicators used in this study. Dept. of Geol., Northern Illinois Univ., DeKalb, IL 60115, USA. 87:6908 Nigam, Rajiv and A.S. Rao, 1987. Prolocuim size vorlatlea in r e c u t bemtl~ FemainUera: impUcatlom for ~ sta~es. Estuar. coast. Shelf Sci., 24(5):649-655.
OLR (1987)34(12)
D. SubmarineGeologyand Geophysics
Ratios of dimorphic (microspheric/megalospheric) forms of Foraminifera are affected by temperature and hence are useful in paleoclimatic studies. In some cases, however, it is not possible to distinguish between the dimorphic forms and, therefore, mean proloculus size is useful. The mean proloculus size of Cavarotalia annectens was measured in 14 surface sediment samples from the near-shore region along the west coast of India (Bombay to Kannyakumari). The results show that mean proloculus size varies from 0.045 to 0.103 ram, and is inversely proportional to temperature and salinity variations. It is proposed, therefore, that mean proloculns size of Foraminifera can be used as an additional tool in paleoclimatic studies. Natl. Inst. of Oceanogr., Dona Paula, Goa 403 004, India. 87:6909 Oggioni, Elisabetta and Liliana Zandini, 1987. Response of benthic Foraminifera to stagnant episodes. A quantitative study of Core BAN 81-23, eastern Mediterranean. Mar. Geol., 75(14):241-261.
Changes in benthic foraminiferal faunas found in a core from the Ares Crater (western Mediterranean Ridge), which included seven sapropel and two tephra layers ranging in age from 5000 to 250,000 yrBP, are described and compared with changes across sapropels $6 through $3 in cores from the nearby Poseidon Plateau (Schilling, 1986). The study shows that a marked reduction in faunal density accompanied the cyclically repeated episodes of stagnation. A consistent sparse faunule of shallowwater epiphytic rotaliforms, probably transported by floating algae and Bolivina spp. and buliminids capable of tolerating very low oxygen levels, was found within the sapropels. Unlike the other layers, the top of sapropel $6 originated under glacial conditions and was preceded by peak abundances of faunal density. Dept. of Earth Sei., Univ. of Milan, Via Manglagalli 34, 20133 Milan, Italy. (hbf) 87:6910 Parisi, Elisabetta, 1987. Carbon and oxygen isotope comlmsition of G/ob~r/ao/des tuber in two deep-sea cores from the Levantine Basin (eastern Mediterrsnean). Mar. Geol., 75(1-4):201-219.
Carbon and oxygen isotope analyses were carried out on 114 samples of G. tuber from two deep-sea cores from the outer slopes of the Mediterranean Ridge. These cores contain the sedimentary history of the eastern Mediterranean in the last 300,000 yr and include sapropelitic layers Ss to S~0. Climatic fluctuations recorded by the isotopic signal correlate well with previous studies; most sapropelitic intervals correspond to warm climatic conditions. Only S6
1055
and partially Ss reflect glacial conditions, indicating an alternative model for the deposition of organicrich layers. The magnitude of fluctuations in oxygen isotope composition (about 7 ppt) is unusually wide for the eastern Mediterranean, and the record is generally shifted toward negative values for approximately 1 ppt, probably due to the Nile discharge. Oxygen and carbon curves are in phase showing the large influence of organic productivity on carbon isotope composition. Dept. of Earth Sei., Univ. of Milan, Via Mangiagalli 34, 20133, Milan, Italy. 87:6911 Patterson, R.T. and R.H. Richardson, 1987. A taxonomic revision of the ~ Forsminffera. J.foram. Res~ 17(3):212-226. Dept. of Earth and Space Sei., Univ. of Calif., Los Angeles, CA 90O24, USA. 87:6912 Por, F.D., 1986. Crustacean ~ of the Late Middle Miocene Middle Eastern landbHdge. Crustacean Issues, 4:69-84.
The low diversity crustacean fauna of the Levantine Basin reflects the influence of several dramatic changes in the region, including the establishment of the Middle Eastern landbridge (dividing the circumtropical Tethys Ocean), a subsequent period of drying, the 'Messinian Salinity Crisis' during which the basin contained only hypersaline lakes and species richness was greatly diminished, the influx of oceanic waters through Gibraltar, a series of Pleistocene cold periods, and cyclical wet and dry periods affecting the surrounding arid lands. The fauna of the Red and Mediterranean seas are compared and the impact of the Suez Canal is examined. Dept. of Zool., Hebrew Univ., Jerusalem, Israel. (gsb) 87:6913 Stabell, Bjerg, 1987. Changes in diatom floras in Late Qummmry wesm'u and southeastern N e ~ i a n marine and f n ~ h ~ ~ m ~ Response to basin isolation from the sea. Nova Hedwigia, 44(3-4):305-326. Dept. of Geol., Univ. of Oslo, P.O. Box 1047, Blindern, N-0316 Oslo 3, Norway. 87:6914 Van Harten, Dick, 1987. Oslrscedes and the Early Holoeene anoxk event in the eastern M e ~ e r ra~an-.-evidanee and ~ Mar. Geol~
75(I-4):263-269. Several species of deep-water ostracodes still common in the western Mediterranean became extinct in the eastern Mediterranean Basin at the onset of early