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Takeshi Nakagawa - One of the best experts on this subject based on the ideXlab platform.

  • pollen Event Stratigraphy of the varved sediment of lake suigetsu central japan from 15 701 to 10 217 sg vyr bp suigetsu varve years before present description interpretation and correlation with other regions
    Quaternary Science Reviews, 2005
    Co-Authors: Takeshi Nakagawa, Hiroyuki Kitagawa, Yoshinori Yasuda, Pavel E Tarasov, Katsuya Gotanda, Yuki Sawai
    Abstract:

    High-resolution pollen data (average interval between samples<15 years) are reported on part of a varved sediment core from Lake Suigetsu, Japan, spanning the interval 15,701 to 10,217 SG vyr BP (Suigetsu varve years Before Present). This new record is compared with a previously proposed Event Stratigraphy based on pollen-based reconstructed changes of mean annual temperature. The deglacial climate history reconstructed at Lake Suigetsu resembles that observed in the North Atlantic, although the major boundaries of pollen zones are asynchronous with those in the North Atlantic Event Stratigraphy by several centuries. The onset of the Late Glacial interstadial occurred earlier in Japan than in the North Atlantic. This demonstrates that the climate in Japan was closely linked to the low-latitude Pacific Sea Surface Temperatures that first reacted to orbital forcing. Conversely, the onset of the subsequent cold reversal phase in Japan lagged that of the North Atlantic (Younger Dryas) by several centuries. The duration of this cold phase was about the same as the Younger Dryas Event, but the amplitude was much reduced (4±2 °C in Δmean annual temperature). These findings support the hypothesis that this pan-hemispheric cooling Event was triggered by North Atlantic forcing, most probably by a meltwater pulse and an associated change in the North Atlantic thermohaline circulation. However, the mechanism which transmitted the change in the North Atlantic to the Far East is unknown.

Birger Schmitz - One of the best experts on this subject based on the ideXlab platform.

  • Foraminiferal and δ13C isotopic Event-Stratigraphy across the Danian–Selandian transition at Zumaya (northern Spain): chronostratigraphic implications
    Terra Nova, 2008
    Co-Authors: Ignacio Arenillas, Eustoquio Molina, Silvia Ortiz, Birger Schmitz
    Abstract:

    unconformity, characterized by a ma- jor lithological shift from greyish white, oxic limestone ⁄ chalk of the Danskekalk Fm., upper Danian, to suboxic, glauconitic green sand of the Lellinge Greensand Fm., lower Selan- dian, overlain by grey marl and clay of the Kerteminde Marl Fm., middle Selandian. This unconformity was correlated with the sequence bound- ary between cycles TA 1.3 and TA 1.4 ABSTRACT The Zumaya section, northern Spain, is a suitable candidate to define the Global Stratotype Section and Point for the base of the Selandian Stage (Palaeocene) because of its excellent accessibility, exposure and stratigraphic continuity. Uncertain- ties exist, however, with regard to the stratigraphic horizon where to place the Danian ⁄ Selandian (D ⁄ S) boundary. Five potential stratigraphic horizons (HDS1 to HDS5) to define the D ⁄ S boundary have been identified at Zumaya, based on integrated stratigraphic studies that include quantitative plank- tic and benthic foraminiferal results, as well as d 13 C isotopic and lithological data. Two of these horizons (HDS2 and HDS4) placed in Zone C26r appear to have particularly good potential for serving as the D ⁄ S boundary marker, because they may represent significant global palaeoceanographic, palaeoclimatic and eustatic Events.

  • foraminiferal and δ13c isotopic Event Stratigraphy across the danian selandian transition at zumaya northern spain chronostratigraphic implications
    Terra Nova, 2008
    Co-Authors: Ignacio Arenillas, Eustoquio Molina, Silvia Ortiz, Birger Schmitz
    Abstract:

    unconformity, characterized by a ma- jor lithological shift from greyish white, oxic limestone ⁄ chalk of the Danskekalk Fm., upper Danian, to suboxic, glauconitic green sand of the Lellinge Greensand Fm., lower Selan- dian, overlain by grey marl and clay of the Kerteminde Marl Fm., middle Selandian. This unconformity was correlated with the sequence bound- ary between cycles TA 1.3 and TA 1.4 ABSTRACT The Zumaya section, northern Spain, is a suitable candidate to define the Global Stratotype Section and Point for the base of the Selandian Stage (Palaeocene) because of its excellent accessibility, exposure and stratigraphic continuity. Uncertain- ties exist, however, with regard to the stratigraphic horizon where to place the Danian ⁄ Selandian (D ⁄ S) boundary. Five potential stratigraphic horizons (HDS1 to HDS5) to define the D ⁄ S boundary have been identified at Zumaya, based on integrated stratigraphic studies that include quantitative plank- tic and benthic foraminiferal results, as well as d 13 C isotopic and lithological data. Two of these horizons (HDS2 and HDS4) placed in Zone C26r appear to have particularly good potential for serving as the D ⁄ S boundary marker, because they may represent significant global palaeoceanographic, palaeoclimatic and eustatic Events.

Stefan Wastegård - One of the best experts on this subject based on the ideXlab platform.

Ignacio Arenillas - One of the best experts on this subject based on the ideXlab platform.

  • Foraminiferal and δ13C isotopic Event-Stratigraphy across the Danian–Selandian transition at Zumaya (northern Spain): chronostratigraphic implications
    Terra Nova, 2008
    Co-Authors: Ignacio Arenillas, Eustoquio Molina, Silvia Ortiz, Birger Schmitz
    Abstract:

    unconformity, characterized by a ma- jor lithological shift from greyish white, oxic limestone ⁄ chalk of the Danskekalk Fm., upper Danian, to suboxic, glauconitic green sand of the Lellinge Greensand Fm., lower Selan- dian, overlain by grey marl and clay of the Kerteminde Marl Fm., middle Selandian. This unconformity was correlated with the sequence bound- ary between cycles TA 1.3 and TA 1.4 ABSTRACT The Zumaya section, northern Spain, is a suitable candidate to define the Global Stratotype Section and Point for the base of the Selandian Stage (Palaeocene) because of its excellent accessibility, exposure and stratigraphic continuity. Uncertain- ties exist, however, with regard to the stratigraphic horizon where to place the Danian ⁄ Selandian (D ⁄ S) boundary. Five potential stratigraphic horizons (HDS1 to HDS5) to define the D ⁄ S boundary have been identified at Zumaya, based on integrated stratigraphic studies that include quantitative plank- tic and benthic foraminiferal results, as well as d 13 C isotopic and lithological data. Two of these horizons (HDS2 and HDS4) placed in Zone C26r appear to have particularly good potential for serving as the D ⁄ S boundary marker, because they may represent significant global palaeoceanographic, palaeoclimatic and eustatic Events.

  • foraminiferal and δ13c isotopic Event Stratigraphy across the danian selandian transition at zumaya northern spain chronostratigraphic implications
    Terra Nova, 2008
    Co-Authors: Ignacio Arenillas, Eustoquio Molina, Silvia Ortiz, Birger Schmitz
    Abstract:

    unconformity, characterized by a ma- jor lithological shift from greyish white, oxic limestone ⁄ chalk of the Danskekalk Fm., upper Danian, to suboxic, glauconitic green sand of the Lellinge Greensand Fm., lower Selan- dian, overlain by grey marl and clay of the Kerteminde Marl Fm., middle Selandian. This unconformity was correlated with the sequence bound- ary between cycles TA 1.3 and TA 1.4 ABSTRACT The Zumaya section, northern Spain, is a suitable candidate to define the Global Stratotype Section and Point for the base of the Selandian Stage (Palaeocene) because of its excellent accessibility, exposure and stratigraphic continuity. Uncertain- ties exist, however, with regard to the stratigraphic horizon where to place the Danian ⁄ Selandian (D ⁄ S) boundary. Five potential stratigraphic horizons (HDS1 to HDS5) to define the D ⁄ S boundary have been identified at Zumaya, based on integrated stratigraphic studies that include quantitative plank- tic and benthic foraminiferal results, as well as d 13 C isotopic and lithological data. Two of these horizons (HDS2 and HDS4) placed in Zone C26r appear to have particularly good potential for serving as the D ⁄ S boundary marker, because they may represent significant global palaeoceanographic, palaeoclimatic and eustatic Events.

Darrel G.f. Long - One of the best experts on this subject based on the ideXlab platform.

  • Oxygen and carbon isotopes and Event Stratigraphy near the Ordovician—Silurian boundary, Anticosti Island Quebec
    Palaeogeography Palaeoclimatology Palaeoecology, 1993
    Co-Authors: Darrel G.f. Long
    Abstract:

    The growth and destruction of continental ice-sheets in North Africa and adjacent parts of Gondwana during the Hirnantian Stage had profound influence on the sedimentary style of mixed carbonate-siliciclastic sequences on Anticosti Island, Quebec, Canada. These strata, deposited in a tropical, mid-shelf setting, show direct evidence of local sea-level changes of up to 40 m. After correction for tectonic and load-induced subsidence this indicates maximum global glacio-eustatic changes of 32 to 36 m. This implies maximum ice volume of about 12 to 14 × 106 km3 and related changes in the oxygen isotopic composition of global sea water amounting to as little as 0.5 to 0.6%. Given that the oxygen isotope ratios in syn-glacial samples from the Anticosti sequence range from −8.9 to −2.8 δ18O, it is not possible to clearly distinguish the effects of ice-cap development from temperature and diagenetic controlled variation. The strong negative shift in δ13C values at the top of the Ellis Bay Formation may indicate a pronounced increase in atmospheric CO2 coincident with destruction of the Late Ordovician ice-caps.

  • oxygen and carbon isotopes and Event Stratigraphy near the ordovician silurian boundary anticosti island quebec
    Palaeogeography Palaeoclimatology Palaeoecology, 1993
    Co-Authors: Darrel G.f. Long
    Abstract:

    The growth and destruction of continental ice-sheets in North Africa and adjacent parts of Gondwana during the Hirnantian Stage had profound influence on the sedimentary style of mixed carbonate-siliciclastic sequences on Anticosti Island, Quebec, Canada. These strata, deposited in a tropical, mid-shelf setting, show direct evidence of local sea-level changes of up to 40 m. After correction for tectonic and load-induced subsidence this indicates maximum global glacio-eustatic changes of 32 to 36 m. This implies maximum ice volume of about 12 to 14 × 106 km3 and related changes in the oxygen isotopic composition of global sea water amounting to as little as 0.5 to 0.6%. Given that the oxygen isotope ratios in syn-glacial samples from the Anticosti sequence range from −8.9 to −2.8 δ18O, it is not possible to clearly distinguish the effects of ice-cap development from temperature and diagenetic controlled variation. The strong negative shift in δ13C values at the top of the Ellis Bay Formation may indicate a pronounced increase in atmospheric CO2 coincident with destruction of the Late Ordovician ice-caps.