Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling

Abstract. The global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma) concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS), off Namibia, where it is known as the Matuyama Diatom Maximum (MDM). Our study focuses on a new diatom silicon isotope (δ30Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ30Si signal follow biogenic opal content, whereby the highest δ30Si values correspond to the highest biogenic opal content. We interpret the higher δ30Si values during the MDM as a result of a stronger degree of silicate utilisation in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Late Pliocene/Early Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California) during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO2 to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO2 release to the atmosphere, led to further enhanced atmospheric CO2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling.

Download Full-text

Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to late Pliocene/early Pleistocene climate cooling

Climate of the Past Discussions ◽

10.5194/cpd-8-669-2012 ◽

2012 ◽

Vol 8 (2) ◽

pp. 669-694

Author(s):

J. Etourneau ◽

C. Ehlert ◽

M. Frank ◽

P. Martinez ◽

R. Schneider

Keyword(s):

Southern Ocean ◽

Coastal Upwelling ◽

Atmospheric Co2 ◽

Early Pleistocene ◽

Silicon Isotope ◽

Time Interval ◽

Nutrient Distribution ◽

Biogenic Opal ◽

Late Pliocene ◽

Polar Ocean

Abstract. The global late Pliocene/early Pleistocene cooling (~3.0–2.0 million years ago, Ma) concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela Upwelling System (BUS), off Namibia, where it is known as the Matuyama Diatom Maximum (MDM). Our study focuses on a new diatom silicon isotope (δ30Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ30Si signal follow biogenic opal content, whereby the highest δ30Si values correspond to the highest biogenic opal content. We interpret the higher δ30Si values during the MDM as a result of a stronger degree of silicate utilization in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Plio/Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California) during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO2 to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO2 release to the atmosphere, led to further enhanced atmospheric CO2 drawn-down and thus contributed significantly to late Pliocene/early Pleistocene cooling.

Download Full-text

Late Cenozoic turnover in the Caribbean reef coral fauna

The Paleontological Society Special Publications ◽

10.1017/s2475262200006031 ◽

1992 ◽

Vol 6 ◽

pp. 43-43

Author(s):

Ann F. Budd ◽

Thomas A. Stemann ◽

Kenneth G. Johnson

Keyword(s):

Shallow Water ◽

Reef Coral ◽

Early Pleistocene ◽

Time Interval ◽

Late Pliocene ◽

Early Pliocene ◽

Coral Fauna ◽

Caribbean Reef ◽

The Caribbean ◽

Faunal Distribution

Study of the stratigraphic ranges of reef coral species in scattered sequences (Dominican Republic, Bahamas, Costa Rica, Jamaica, and Florida) suggests that a major episode of faunal turnover occurred in the Caribbean region between early Pliocene and mid Pleistocene time. In a data set composed of all reef corals except the families Mussidae and Oculinidae and the genera Cladocora and Madracis, approximately 90% of the Mio-Pliocene fauna, composed of as many as 65–70 species, became extinct during this time interval. Ten of 27 genera became extinct. Despite the high numbers of extinctions, the total number of species in the Caribbean reef coral fauna dropped only slightly over the time interval, due to similar numbers of originations and extinctions in the fauna. With one possible exception, new species arose in surviving genera, and no new genera formed.Although similar numbers of species became extinct within early Pliocene, late Pliocene, and early Pleistocene time units, shallow water communities experienced higher numbers of extinctions during the late Miocene and early Pliocene. Deeper water communities experienced higher numbers of extinctions during the late Pliocene and early Pleistocene. Species surviving the turnover episode occur in deeper water communities and belong predominantly to the family Agariciidae. Nearshore grass flat communities contain the highest number of early extinctions. No difference in extinction patterns could be detected between taxa which reproduce primarily by fragmentation and those that reproduce primarily by larval recruitment. Although originations appear evenly distributed among community types, a large number occur in Florida along the northern margin of faunal distribution.The increased extinctions in shallow water communities and increased originations in the north suggest that turnover occurred primarily in response to change in abiotic factors such as temperature and siltation, and not in response to species-area effects associated with sea level change.

Download Full-text

Evidence of Late Pliocene-Early Pleistocene Environmental Change and Possible Coastal Upwelling Based on Marine Ostracodes from the Moin Formation, Costa Rica: ABSTRACT

AAPG Bulletin ◽

10.1306/7834da8a-1721-11d7-8645000102c1865d ◽

1995 ◽

Vol 79 ◽

Author(s):

Pamela F. Borne

Keyword(s):

Costa Rica ◽

Environmental Change ◽

Coastal Upwelling ◽

Early Pleistocene ◽

Late Pliocene

Download Full-text

Stratigraphy and paleoecology of the Late Pliocene and Early Pleistocene in the open-cast mine Hambach (Lower Rhine Basin)

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/s0016774600022435 ◽

2002 ◽

Vol 81 (2) ◽

pp. 193-199 ◽

Cited By ~ 15

Author(s):

G. Heumann ◽

Th. Litt

Keyword(s):

High Energy ◽

Climatic Conditions ◽

Oxbow Lake ◽

Early Pleistocene ◽

Time Interval ◽

Late Pliocene ◽

Lignite Mine ◽

Lower Rhine Basin ◽

Open Cast ◽

Lower Rhine

AbstractMore than 400 samples for paleobotanical and sedimentological investigations were collected from Late Pliocene and earliest Pleistocene beds in the open-cast lignite mine Hambach. They were analysed to obtain information about the paleoecology and paleoclimate of this time interval. The sedimentation type changed from a high-energy meandering fluvial system to floodplain, swamp and oxbow lake sedimentation. The typical Tertiary floral elements decreased with the onset of increasingly cooler climatic conditions and disappeared at the beginning of the Pleistocene to be substituted by a impoverished and coldadapted flora. These combined litho- and biostratigraphic investigations led to an improved and reproducible separation of Late Pliocene from Early Pleistocene deposits.

Download Full-text

Regional late Pliocene-early Pleistocene hiatuses of the Southern Ocean — Diatom evidence

Marine Geology ◽

10.1016/0025-3227(87)90112-5 ◽

1987 ◽

Vol 77 (3-4) ◽

pp. 207-218 ◽

Cited By ~ 10

Author(s):

Lloyd H. Burckle ◽

Nelson Abrams

Keyword(s):

Southern Ocean ◽

Early Pleistocene ◽

Late Pliocene

Download Full-text

Plio-Pleistocene Amphibians and Reptiles from Central Turkey: New Faunas and Faunal Records with Comments on their Biochronological Position Based on Small Mammals

Fossil Imprint ◽

10.2478/if-2019-0022 ◽

2019 ◽

Vol 75 (3-4) ◽

pp. 343-358

Author(s):

Elena Syromyatnikova ◽

Alexey Tesakov ◽

Serdar Mayda ◽

Tanju Kaya ◽

Gerçek Saraç

Keyword(s):

Small Mammals ◽

Eastern Mediterranean ◽

Central Anatolia ◽

Early Pleistocene ◽

Middle Pleistocene ◽

Time Interval ◽

Late Pliocene ◽

Early Pliocene ◽

Central Turkey ◽

First Time

Abstract Small fossil vertebrates from several Pliocene and Pleistocene localities in Central Anatolia (Turkey) are reviewed. Data on small mammals represent assemblages from the early Pliocene (MN 14: Nasrettinhoca 1, 2 and Hamamkarahisar A, B), and late Pliocene (MN 16: Hoyhoytepe 1, 2, 3 and Mercan 1); Early Pleistocene (MN 17: Mercan 2), and Middle Pleistocene (MQ 1/MQ 2: Yenişarbademli). The biochronology related characters of arvicolines Promimomys, Mimomys, Microtus, Lagurus and Clethrionomys are briefly discussed. Data on the systematics of fossil amphibians and reptiles is also described from these localities. The early Pliocene (MN 14) assemblages significantly add to knowledge on the herpetofaunal composition of this stratigraphic level, which until now was poorly characterized in Turkey. Remains of Pelobatidae, Bufonidae, Ranidae, Amphisbaenia and Natricinae are reported for the first time from the MN 14 biozone of Turkey. Palaeobatrachus from Mercan 1 extends the temporal range of this group in the Eastern Mediterranean into the late Pliocene. The described remains of amphibians and reptiles from Turkey span a considerable stratigraphic range from the early Pliocene to the Middle Pleistocene (time interval of about 5 Ma) and partly fill a gap in the palaeoherpetofaunal record of the Eastern Mediterranean.

Download Full-text

Evidence of 'Mid-Pliocene (~3 Ma) global warmth' in the eastern Arctic Ocean and implications for the Svalbard/Barents Sea ice sheet during the late Pliocene and early Pleistocene (~3-1.7 Ma)

Boreas ◽

10.1080/03009480210652 ◽

2002 ◽

Vol 31 (1) ◽

pp. 82-93 ◽

Cited By ~ 26

Author(s):

Jochen Knies ◽

Jens Matthiessen ◽

Christoph Vogt ◽

Ruediger Stein

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Barents Sea ◽

Ice Sheet ◽

Early Pleistocene ◽

Late Pliocene

Download Full-text

Volume and Nutrient Transports Disturbed by the Typhoon Chebi (2013) in the Upwelling Zone East of Hainan Island, China

Journal of Marine Science and Engineering ◽

10.3390/jmse9030324 ◽

2021 ◽

Vol 9 (3) ◽

pp. 324

Author(s):

Manli Zheng ◽

Lingling Xie ◽

Quanan Zheng ◽

Mingming Li ◽

Fajin Chen ◽

...

Keyword(s):

South China Sea ◽

Coastal Upwelling ◽

Unit Area ◽

Hainan Island ◽

Volume Transport ◽

Coastal Ocean ◽

Offshore Water ◽

Nutrient Distribution ◽

Before And After ◽

Ekman Flow

Using cruise observations before and after the typhoon Chebi in August 2013 and those without the typhoon in July 2012, this study investigates variations in current structure, nutrient distribution, and transports disturbed by a typhoon in a typical coastal upwelling zone east of Hainan Island in the northwestern South China Sea. The results show that along-shore northeastward flow dominates the coastal ocean with a volume transport of 0.64 × 106 m3/s in the case without the typhoon. The flow reversed southwestward, with its volume transport halved before the typhoon passage. After the typhoon passage, the flow returned back northeastward except the upper layer in waters deeper than 50 m and the total volume transport decreased to 0.10 × 106 m3/s. For the cross-shelf component, the flow kept shoreward, while transports crossing the 50 m isobath decreased from 0.25, 0.12 to 0.06 × 106 m3/s in the case without the typhoon as well as before and after typhoon passage, respectively. For the along-shore/cross-shelf nutrient transports, SiO32− has the largest value of 866.13/632.74 μmol/s per unit area, NO3− half of that, and PO43− and NO2− one order smaller in the offshore water without the typhoon. The values dramatically decreased to about one-third for SiO32−, NO3−, and PO43− after the typhoon, but changed little for NO2−. The disturbed wind field and associated Ekman flow and upwelling process may explain the variations in the current and nutrient transports after the typhoon.

Download Full-text