Anomalous South Atlantic lithologies confirm global scale of unusual mid-Pleistocene climate excursion

Gingele, Franz; Schmieder, Frank

doi:10.1016/s0012-821x(01)00234-5

Cited by 29 publications

(30 citation statements)

References 36 publications

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“…It is absent from stage 1 and also during deglaciation and the later part of the LGM, periods when a strong bulk carbonate maximum occurs. The combination of an E. rex layer followed by a strong carbonate maximum has been found in mid-Pleistocene sediments of the Atlantic (Gingele and Schmieder, 2001) and has been interpreted as a consequence of reduced thermohaline circulation, followed by the subsequent onset of more turbulent conditions. A similar scenario may be applicable to BAR9442.…”

Section: Biogenic Proxiesmentioning

confidence: 92%

“…Ecophysiological investigations on E. rex and other deep-dwelling diatoms (Villareal, 1993;Villareal et al, 1993;Villareal and Carpenter, 1994;Pike and Kemp, 1999;Yoder et al, 1994;Kemp et al, 1999), and the discovery of extensive E. rex deposits in the Atlantic (Stabell, 1986;Abrantes et al, 1994;Gingele and Schmieder, 2001) and the Indian Ocean (Broecker et al, 2000) have focussed new attention on the behavior, autecology and paleoceanographic signi¢cance of E. rex. As E. rex is rarely found in surface plankton samples today, and is regarded as a character species of oligotrophic seas (Villareal, 1993), the formation of mass accumulation in sediments has long remained an enigma.…”

Section: Biogenic Proxiesmentioning

confidence: 99%

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History of the South Java Current over the past 80 ka

Gingele

Deckker

Girault

et al. 2002

Palaeogeography, Palaeoclimatology, Palaeoecology

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A sediment core located below the present South Java Current (SJC) was used to reconstruct paleoclimate and paleoceanography on the basis of biogenic and terrigenic proxy-records. The core spans the past 80 ka of environmental change and shows considerable contrasts from the glacial to the Holocene. Presently, the core site is situated beneath a seasonally varying low-salinity tongue which is advected from the Java Sea via the Sunda Strait. It carries terrigenous matter of a characteristic signature. During the last glacial period (stage 4-2), when sea level was lower than during the Holocene, the Sunda Strait was closed and the terrigenous supply from that source ceased. As the core site is close to the equator, our results indicate that atmospheric and oceanographic circulation was alternatively dominated by the Northern Hemisphere East Asian Monsoon system and the Southern Hemisphere Australian Monsoon system. Between 20 and 12 ka, the (Australian) SE Winter Monsoon reached its maximum and intensified the westward flowing SJC. Increased mixing of the surface waters led to a slight rise in paleoproductivity. A similar but much weaker situation prevailed from 74 to 70 ka. During most of the glacial period, from 70 to 20 ka, strong northeasterly winds associated with the East Asian Winter Monsoon intensified the Indian Monsoon Current and the eastward flowing SJC, and may have also carried dust across the equator to our core site. During this glacial phase, populations of the giant diatom Ethmodiscus rex were thriving and may indicate a reduced deep and intermediate thermohaline circulation at the site. The monsoonal system as we know it today, with distinct dry and wet seasons, may not have been active before V12 ka. ß

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Section: Biogenic Proxiesmentioning

confidence: 92%

Section: Biogenic Proxiesmentioning

confidence: 99%

History of the South Java Current over the past 80 ka

Gingele

Deckker

Girault

et al. 2002

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…The location of these deposits has been related to a possible extreme northerly position for the Subtropical Front (Gingele and Schmieder, 2001) while their timing has been related to a broader body of evidence for a widespread return to more humid conditions in low latitudes at this time with enhanced weathering and run-off delivering silica-enriched water as well as isotopically light carbon (Wang et al, 2004). An alternative but possibly complementary explanation connects the silica availability to an abrupt strengthening of the thermohaline circulation (Gingele and Schmieder, 2001); (Romero and Schmieder, 2006) From Termination V, for the last four 100 kyr glacial cycles, the APF has occupied its most southerly Pleistocene position and has undergone similar glacial-interglacial migrations. Therefore, although the 100,000 year cycles may have been established from around 640 ka, a step-change in the location of the APF, and an associated fundamental reorganisation of the Earth system (ocean circulation, temperature, CO 2 , ice volume) did not occur until the amplitude of glacial-interglacial cycles increased to that characteristic of the last 400 kyr at the MBE.…”

mentioning

confidence: 99%

Migration of the Antarctic Polar Front through the mid-Pleistocene transition: evidence and climatic implications

Kemp

Grigorov

Pearce

et al. 2010

Quaternary Science Reviews

108

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“…rex frustules (Figure ). Considering the dominant eolian source of DSi (see section 4.4.1) and stratified conditions of the EPS [ Gingele and Schmieder , ; De Deckker and Gingele , ; Kemp and Villareal , ], the δ 30 Si of the DSi source for E . rex blooms may have been nearly constant during the LGM.…”

Section: Discussionmentioning

confidence: 99%

“…Each model has regional applicability: strong oceanic stratification is linked to E . rex blooms in the tropical ocean [e.g., Gingele and Schmieder , ; De Deckker and Gingele , ; Kemp and Villareal , ] and frontal zones to blooms in subtropical settings [e.g., Pike , ; Kemp et al ., ; Rackebrandt et al ., ]. Both models invoke deep nutrient pools for E .…”

Section: Introductionmentioning

confidence: 99%

The silicon isotope composition of Ethmodiscus rex laminated diatom mats from the tropical West Pacific: Implications for silicate cycling during the Last Glacial Maximum

Xiong

Algeo

et al. 2015

Paleoceanography

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The cause of massive blooms of Ethmodiscus rex laminated diatom mats (LDMs) in the easternPhilippine Sea (EPS) during the Last Glacial Maximum (LGM) remains uncertain. In order to better understand the mechanism of formation of E. rex LDMs from the perspective of dissolved silicon (DSi) utilization, we determined the silicon isotopic composition of single E. rex diatom frustules (δ 30 Si E. rex ) from two sediment cores in the Parece Vela Basin of the EPS. In the study cores, δ 30 Si E. rex varies from À1.23‰ to À0.83‰ (average À1.04‰), a range that is atypical of marine diatom δ 30Si and that corresponds to the lower limit of reported diatom δ 30Si values of any age. A binary mixing model (upwelled silicon versus eolian silicon) accounting for silicon isotopic fractionation during DSi uptake by diatoms was constructed. The binary mixing model demonstrates that E. rex dominantly utilized DSi from eolian sources (i.e., Asian dust) with only minor contributions from upwelled seawater sources (i.e., advected from Subantarctic Mode Water, Antarctic Intermediate Water, or North Pacific Intermediate Water). E. rex utilized only~24% of available DSi, indicating that surface waters of the EPS were eutrophic with respect to silicon during the LGM. Our results suggest that giant diatoms did not always use a buoyancy strategy to obtain nutrients from the deep nutrient pool, thus revising previously proposed models for the formation of E. rex LDMs.

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Anomalous South Atlantic lithologies confirm global scale of unusual mid-Pleistocene climate excursion

Cited by 29 publications

References 36 publications

History of the South Java Current over the past 80 ka

History of the South Java Current over the past 80 ka

Migration of the Antarctic Polar Front through the mid-Pleistocene transition: evidence and climatic implications

The silicon isotope composition of Ethmodiscus rex laminated diatom mats from the tropical West Pacific: Implications for silicate cycling during the Last Glacial Maximum

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