Middle Miocene deepwater paleoceanography in the southwest Pacific: Relations with East Antarctic Ice Sheet development

Flower, B. P.; Kennett, James P.

doi:10.1029/95pa02022

Cited by 161 publications

(96 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The supply of cool intermediate waters to mid-latitude surface waters in the upwelling regions progressively decreased moisture levels in the atmosphere in the hinterland (Flower and Kennet, 1995), which established the initiation of the Benguela upwelling and the formation of the Namib Desert (Siesser, 1978). Accordingly, aridification in southern Africa is documented at 10 Ma from isotope and geochemical studies in the Walvis Bay (Partridge, 1993), Meteor Rise (Site 1088) at 9.7 Ma from a clay mineral study (Diekmann et al, 2003), and Cape Basin at 9.6 Ma based on the oxygen isotope record at Site 1085 (Westerhold et al, 2005).…”

Section: Background and Regional Settingmentioning

confidence: 99%

Controls on carbonate and terrigenous deposition in the incipient Benguela upwelling system during the middle to the late Miocene (ODP Sites 1085 and 1087)

Kastanja

Diekmann

Henrich

2006

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

This study deals with the variability of biogenic carbonate and terrigenous depositional patterns in the Cape Basin area of the South Atlantic during the middle to the late Miocene focusing on ODP Sites 1085 and 1087 sediments at the Benguela Upwelling area, Southwest Africa. The investigations are based on grain-size analysis and clay mineralogy. The sedimentary records at both sites provide information about climate and environmental changes. The direct input of terrigenous material from southwestern Africa is driven by a complex interaction of river and wind transport, and ocean currents. The considerable amount of dust input derived from the Namib Desert started to become important after 11.2 Ma, pointing to an increased supply of cool intermediate waters to mid-latitude surface waters in the upwelling regions, which coincided with the establishment of the winddriven Benguela upwelling system. A major drop in CaCO 3 concentration between 10.4 and 10.1 Ma is caused mainly by changes in calcareous nannoplankton production, while another drop between 9.6 and 9 Ma is triggered by a combination of production changes of calcareous nannoplankton and dilution, in response to high shelf supply during global lowering of the sea level.

show abstract

Section: Background and Regional Settingmentioning

confidence: 99%

Controls on carbonate and terrigenous deposition in the incipient Benguela upwelling system during the middle to the late Miocene (ODP Sites 1085 and 1087)

Kastanja

Diekmann

Henrich

2006

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

show abstract

“…The position of the AAPF south of New Zealand is closely linked to the Australian-Pacific ocean spreading ridge (Nelson & Cooke 2001) and the wind speed of the polar westerlies (Perry & Walker 1977). The establishment of the West Antarctic Ice Sheet (WAIS) between 10 and 8 Ma (Ciesielski et al 1982;Kennett & von der Borch 1986a) resulted in the meridional thermal gradient increasing, which in turn increased the volume of the middle-late Miocene SCIW (Flower & Kennett 1995). General changes in Pacific Ocean circulation intensity between 10 and 8 Ma have been inferred from fluxes in the biogenic opal record, which supports intensification in the Southern Hemisphere trade winds and equatorial upwelling (Leinen 1979).…”

Section: Paleoceanographic Interpretationsmentioning

confidence: 99%

“…The increased winnowing at c. 9.5-8 Ma in Hole 593 sediments could reflect a similar delay between ice volume increase and oceanic changes in the Tasman Sea, a consequence of the middle-late Miocene isotope events identified in the oxygen isotope record from the region (Flower & Kennett 1995;Cooke 2002). Miocene glacial events Mi5 and Mi6 (c. 11.5-10.4 Ma) are interpreted as significant ice volume increases contributing to the development of the West Antarctic Ice Sheet (WAIS).…”

Section: Paleoceanographic Interpretationsmentioning

confidence: 99%

See 1 more Smart Citation

Textural variations in Neogene pelagic carbonate ooze at DSDP Site 593, southern Tasman Sea, and their paleoceanographic implications

Cooke¹,

Nelson

Crundwell

et al. 2004

New Zealand Journal of Geology and Geophysics

View full text Add to dashboard Cite

Changes in Neogene sediment texture in pelagic carbonate-rich oozes on the Challenger Plateau, southern Tasman Sea, are used to infer changes in depositional paleocurrent velocities. The most obvious record of textural change is in the mud: sand ratio. Increases in the sand content are inferred to indicate a general up-core trend towards increasing winnowing of sediments resulting from increasing flow velocity of Southern Component Intermediate Water (SCIW), the forerunner of Antarctic Intermediate Water. In particular, the intervals c. 19-14.5 Ma, c. 9.5-8 Ma, and after 5 Ma are suggested to be times of increased SCIW velocity and strong sediment winnowing. Within the mud fraction, the fine silt to coarse clay sizes from 15.6 to 2 µm make the greatest contribution to the sediments and are composed of nannofossil plates. During extreme winnowing events it is the fine silt to very coarse clay material (13-3 µm) within this range that is preferentially removed, suggesting the 10 µm cohesive silt boundary reported for siliciclastic sediments does not apply to calcitic skeletal grains. The winnowed sediment comprises coccolithophore placoliths and spheres, represented by a mode at 4-7 µm.Further support for seafloor winnowing is gained from the presence in Hole 593 of a condensed sedimentary section from c. 18 to 14 Ma where the sand content increases to c. 20% of the bulk sample. Associated with the condensed section is a 6 m thick orange unit representing sediments subjected to particularly oxygen-rich, late early to early middle Miocene SCIW. Together these are inferred to indicate increased SCIW velocity resulting in winnowed sediment associated with faster arrival of oxygen-rich surface water subducted to form SCIW. Glacial development of Antarctica has been recorded from many deep-sea sites, with extreme glacials providing the mechanism to increase watermass flow. Miocene glacial zones Mi1b-Mi6 are identified in an associated oxygen isotope record from Hole 593, and correspond with times of particularly invigorated paleocirculation, bottom winnowing, and sediment textural changes.

show abstract

“…The Mi-1 gla cial pulse ini ti ated a se ries of brief and smaller glaciations in Antarctica and then the Earth be gan to cool rapidly in the Mid dle Mio cene. The on set of the ma jor ex pan sion of the East Ant arc tic Ice Sheet be tween 14 and 13 Ma (Flower and Ken nett, 1995) trig gered pulses of ex tinc tion in both the ma rine and ter res trial realms dur ing this in ter val of time (Sepkoski, 1996;Lewis et al, 2008). By 12 Ma mas sive ice sheets had formed in east ern Antarctica that per sist to the pres ent day.…”

Section: A Comparison Of Cenozoic and Late Paleozoic Global Coolingmentioning

confidence: 99%

The Late Devonian (Frasnian/Famenian) mass extinction: a proposed test of the glaciation hypothesis

McGhee

2014

View full text Add to dashboard Cite

In this pa per it is agued that Late Frasnian global cool ing was the first step in the on set of the Late Pa leo zoic Ice Age, and that a Late Frasnian gla ci ation ex isted that was anal o gous to the early Oligocene (Oi-1) gla ci ation that took place in the first step of global cool ing in the on set of the Ce no zoic Ice Age. It is here pro posed that de fin i tive sedimentological ev i dence for the exis tence of Late Frasnian gla ci ation, like the Oi-1 gla ci ation, would be the dis cov ery of ice-rafted de bris in ma rine sed i ments of Late Frasnian age sim i lar to the ice-rafted de bris found in Oi-1 ma rine sed i ments (Zachos et al., 1992;Ehrmann and Mackensen, 1992). Rather than metre-to decimetre-sized ice-rafted de bris, a search should be ini ti ated for the pres ence of sand-sized (>250 mm) ice-rafted de bris in Frasnian ma rine strata lo cated off shore from the main Gond wana land mass, and dated to the Late rhenana Cono dont Zone and/or to the linguiformis-Early triangularis cono dont zonal in ter val where the extinc tions and sharp drops in sea-sur face tem per a ture oc curred (Joachimski and Buggisch, 2002).

show abstract

Middle Miocene deepwater paleoceanography in the southwest Pacific: Relations with East Antarctic Ice Sheet development

Cited by 161 publications

References 41 publications

Controls on carbonate and terrigenous deposition in the incipient Benguela upwelling system during the middle to the late Miocene (ODP Sites 1085 and 1087)

Controls on carbonate and terrigenous deposition in the incipient Benguela upwelling system during the middle to the late Miocene (ODP Sites 1085 and 1087)

Textural variations in Neogene pelagic carbonate ooze at DSDP Site 593, southern Tasman Sea, and their paleoceanographic implications

The Late Devonian (Frasnian/Famenian) mass extinction: a proposed test of the glaciation hypothesis

Contact Info

Product

Resources

About