- Email: [email protected]
Sedimentological features of the detrital deposits from the Pestera cu Oase (Banat Mountains, Romania), as Quaternary paleoclimate proxies
344
Abstracts / Quaternary International 279-280 (2012) 233–345
elemental ratios (XRF) and bulk mineralogy (XRD). The variations found in the analyzed parameters are correlated with the paleohydrodynamic regime fluctuations which are, in turn, influenced by the paleoclimate oscillations. SEDIMENTOLOGICAL FEATURES OF THE DETRITAL DEPOSITS FROM THE PESTERA CU OASE (BANAT MOUNTAINS, ROMANIA), AS QUATERNARY PALEOCLIMATE PROXIES Cristian-Mihai Munteanu. Emil Racovita Institute of Speleology, Romania E-mail address: [email protected]
The Quaternary paleoclimate oscillations in the Banat Mountains area (Romania) have been recorded in a detrital sequence filling up the shaft from the Pestera cu Oase. We describe the lithostratigraphy and sedimentological parameters of the deposit (grain size, morphometry), adding also rock magnetic, geochemical (XRF, calcimetry, organic matter content) and mineralogical (XRD) data. The age of the sedimentary sequence is constrained by a U-series dated "candlestick" stalagmite taken from the top of the sediments and three cave bear bone fragments that have been ESRdated. Rock magnetic properties allowed the identification of Quaternary climate oscillations. The main magnetic mineral is hematite, but the climate variations can be correlated with the presence of magnetite/maghemite, related to the pedogenesis outside the cave and transported underground by the stream. We correlate the rock magnetic data with the marine oxygen isotope record, to highlight the presence of cooler and warmer intervals (the first two of latter pertaining to MIS 3 and the last one to MIS 5a). The sedimentation begun during the relatively cold stage MIS 5b and ceased right at the and of the Last Glacial Maximum, w16.5 ka ago. SPATIAL AND TEMPORAL COMPARISON OF SPHEROIDAL CARBONACEOUS PARTICLES IN EAST ASIAN LAKE SEDIMENTS
The post-Last Glacial Maximum (LGM) transition reflects global climate dynamics and forcing mechanisms whose influence in the southern midlatitudes remains unclear. Delineating the location and timing of the LGM termination and subsequent climate reversals in the Southern Andes can help quantify past climates in this region. Ice cap expansion and retreat may be linked to the migration of the Southern Westerlies and the Antarctic polar front, and may reflect influences from Antarctica or elsewhere. We examine glacial activity adjacent to the Southern Patagonian Icefield via new 10Be surface exposure dating of a remarkably intact set of moraines, located in little-studied area at 49-50oS, which includes both large outlet valleys and smaller valleys on an interfluve. 10Be ages indicate that the Santa Teresita moraine in the Lago Viedma Valley, the Puerto Bandera moraine in the Lago Argentino Valley (Ackert et al., 2008, Science) and several smaller moraines in the Rio Guanaco Valley were deposited either during, or after, the LGM. Interpretations of the post-LGM sequence hinge strongly on the choice of 10Be production rate. Using a production rate derived from New Zealand, ice retreated in the Rio Guanaco Valley at w18 ka, whereas the Santa Teresita and Puerto Bandera moraines reflect an enlarged ice cap at w13 ka. These findings are consistent with a fullycoupled transient general circulation model that predicts minimal precipitation change but significantly lower temperatures and ELAs w14 ka, followed by warming at w13.5 ka. In this scenario, the Antarctic Cold Reversal was felt as far north as 50oS. Alternatively, the global 10Be production rate (CRONUS) indicates initial ice retreat at w16 ka (Rio Guanaco) and subsequent expansion of the ice cap w11 ka as recorded by the Santa Teresita and Puerto Bandera moraines. This implies glacier retreat after the Younger Dryas interval, and requires an explanation other than hemisphere-scale cooling linked to the ACR. COSMOGENIC AGE CONSTRAINTS ON THE LAST DEGLACIATION IN SOUTHERN PATAGONIA (49 - 50 S) Daniel Murray. University of Wisconsin-Madison, United States
Akiko Murakami-Kitase. Waseda University, Japan
E-mail address: [email protected]
E-mail address: [email protected]
Recently in East Asia the amount of fossil fuel combustion have increased with economic growth. It has caused a problem of trans-boundary air pollution in the whole of eastern Asia. In this study, we evaluated the sedimentary records of spheroidal carbonaceous particles (SCPs) and heavy metal derived from anthropogenic combustion in eastern Asia (Japan, Korea, and China) to compare the record of fossil fuel combustion in each area. To date the sediment cores, 210 Pb and 137Cs dating method was applied. The concentration of SCPs in industrial cities in Japan showed characteristic trend as follows; 1) the start of the record in 1930s, 2) the peak of 1960s – 1970s, 3) the decrease from 1980s to the present. These trends reflect the history of the fossil fuel combustion and pollution control around each industrial area, respectively. In isolated islands on the Japan Sea, the SCPs trend shows the start of the record in 1950s – 1960s, and gradual increase to the present. The SCPs trend in the northeastern Korea shows increasing upward. On the other hand, the trend in the central Korea showed the peak in a particular depth and decreasing upward. The SCPs trend in China (Beijing, Tsingtao, and Nanjing) showed increasing from 1990s to the present. These results showed SCPs profiles in Japan, Korea, and China has different trend, respectively. Additionally, morphological and chemical characteristics of SCPs observed by SEM/EDS between these countries are different. These findings suggest that most of SCPs in sediments in an industrial city would be derived from the area, indicating that a large proportion of SCPs hardly transport long distance. However few SCPs are found in isolated islands, suggesting that a small portion of SCPs transport long distance (at least 100km). Therefore SCPs profiles in an isolated area play an important role to clarify the long distance transport of materials originated from fossil fuel combustion in past and present in eastern Asia. COSMOGENIC AGE CONSTRAINTS ON THE LAST DEGLACIATION IN SOUTHERN PATAGONIA (49 - 50 S) Daniel Murray. University of Wisconsin-Madison, United States E-mail address: [email protected]
The post-Last Glacial Maximum (LGM) transition reflects global climate dynamics and forcing mechanisms whose influence in the southern midlatitudes remains unclear. Delineating the location and timing of the LGM termination and subsequent climate reversals in the Southern Andes can help quantify past climates in this region. Ice cap expansion and retreat may be linked to the migration of the Southern Westerlies and the Antarctic polar front, and may reflect influences from Antarctica or elsewhere. We examine glacial activity adjacent to the Southern Patagonian Icefield via new 10Be surface exposure dating of a remarkably intact set of moraines, located in little-studied area at 49-50oS, which includes both large outlet valleys and smaller valleys on an interfluve. 10Be ages indicate that the Santa Teresita moraine in the Lago Viedma Valley, the Puerto Bandera moraine in the Lago Argentino Valley (Ackert et al., 2008, Science) and several smaller moraines in the Rio Guanaco Valley were deposited either during, or after, the LGM. Interpretations of the post-LGM sequence hinge strongly on the choice of 10Be production rate. Using a production rate derived from New Zealand, ice retreated in the Rio Guanaco Valley at w18 ka, whereas the Santa Teresita and Puerto Bandera moraines reflect an enlarged ice cap at w13 ka. These findings are consistent with a fullycoupled transient general circulation model that predicts minimal precipitation change but significantly lower temperatures and ELAs w14 ka, followed by warming at w13.5 ka. In this scenario, the Antarctic Cold Reversal was felt as far north as 50oS. Alternatively, the global 10Be production rate (CRONUS) indicates initial ice retreat at w16 ka (Rio Guanaco) and subsequent expansion of the ice cap w11 ka as recorded by the Santa Teresita and Puerto Bandera moraines. This implies glacier retreat after the Younger Dryas interval, and requires an explanation other than hemisphere-scale cooling linked to the ACR. THERMOKARST IN THE GEOLOGICAL RECORD Julian Murton. University of Sussex, United Kingdom E-mail address: [email protected]
Thermokarst denotes the processes, landforms and sediments associated with ablationdusually by thawingdof excess ice in permafrost. Because
Abstracts / Quaternary International 279-280 (2012) 233–345
elemental ratios (XRF) and bulk mineralogy (XRD). The variations found in the analyzed parameters are correlated with the paleohydrodynamic regime fluctuations which are, in turn, influenced by the paleoclimate oscillations. SEDIMENTOLOGICAL FEATURES OF THE DETRITAL DEPOSITS FROM THE PESTERA CU OASE (BANAT MOUNTAINS, ROMANIA), AS QUATERNARY PALEOCLIMATE PROXIES Cristian-Mihai Munteanu. Emil Racovita Institute of Speleology, Romania E-mail address: [email protected]
The Quaternary paleoclimate oscillations in the Banat Mountains area (Romania) have been recorded in a detrital sequence filling up the shaft from the Pestera cu Oase. We describe the lithostratigraphy and sedimentological parameters of the deposit (grain size, morphometry), adding also rock magnetic, geochemical (XRF, calcimetry, organic matter content) and mineralogical (XRD) data. The age of the sedimentary sequence is constrained by a U-series dated "candlestick" stalagmite taken from the top of the sediments and three cave bear bone fragments that have been ESRdated. Rock magnetic properties allowed the identification of Quaternary climate oscillations. The main magnetic mineral is hematite, but the climate variations can be correlated with the presence of magnetite/maghemite, related to the pedogenesis outside the cave and transported underground by the stream. We correlate the rock magnetic data with the marine oxygen isotope record, to highlight the presence of cooler and warmer intervals (the first two of latter pertaining to MIS 3 and the last one to MIS 5a). The sedimentation begun during the relatively cold stage MIS 5b and ceased right at the and of the Last Glacial Maximum, w16.5 ka ago. SPATIAL AND TEMPORAL COMPARISON OF SPHEROIDAL CARBONACEOUS PARTICLES IN EAST ASIAN LAKE SEDIMENTS
The post-Last Glacial Maximum (LGM) transition reflects global climate dynamics and forcing mechanisms whose influence in the southern midlatitudes remains unclear. Delineating the location and timing of the LGM termination and subsequent climate reversals in the Southern Andes can help quantify past climates in this region. Ice cap expansion and retreat may be linked to the migration of the Southern Westerlies and the Antarctic polar front, and may reflect influences from Antarctica or elsewhere. We examine glacial activity adjacent to the Southern Patagonian Icefield via new 10Be surface exposure dating of a remarkably intact set of moraines, located in little-studied area at 49-50oS, which includes both large outlet valleys and smaller valleys on an interfluve. 10Be ages indicate that the Santa Teresita moraine in the Lago Viedma Valley, the Puerto Bandera moraine in the Lago Argentino Valley (Ackert et al., 2008, Science) and several smaller moraines in the Rio Guanaco Valley were deposited either during, or after, the LGM. Interpretations of the post-LGM sequence hinge strongly on the choice of 10Be production rate. Using a production rate derived from New Zealand, ice retreated in the Rio Guanaco Valley at w18 ka, whereas the Santa Teresita and Puerto Bandera moraines reflect an enlarged ice cap at w13 ka. These findings are consistent with a fullycoupled transient general circulation model that predicts minimal precipitation change but significantly lower temperatures and ELAs w14 ka, followed by warming at w13.5 ka. In this scenario, the Antarctic Cold Reversal was felt as far north as 50oS. Alternatively, the global 10Be production rate (CRONUS) indicates initial ice retreat at w16 ka (Rio Guanaco) and subsequent expansion of the ice cap w11 ka as recorded by the Santa Teresita and Puerto Bandera moraines. This implies glacier retreat after the Younger Dryas interval, and requires an explanation other than hemisphere-scale cooling linked to the ACR. COSMOGENIC AGE CONSTRAINTS ON THE LAST DEGLACIATION IN SOUTHERN PATAGONIA (49 - 50 S) Daniel Murray. University of Wisconsin-Madison, United States
Akiko Murakami-Kitase. Waseda University, Japan
E-mail address: [email protected]
E-mail address: [email protected]
Recently in East Asia the amount of fossil fuel combustion have increased with economic growth. It has caused a problem of trans-boundary air pollution in the whole of eastern Asia. In this study, we evaluated the sedimentary records of spheroidal carbonaceous particles (SCPs) and heavy metal derived from anthropogenic combustion in eastern Asia (Japan, Korea, and China) to compare the record of fossil fuel combustion in each area. To date the sediment cores, 210 Pb and 137Cs dating method was applied. The concentration of SCPs in industrial cities in Japan showed characteristic trend as follows; 1) the start of the record in 1930s, 2) the peak of 1960s – 1970s, 3) the decrease from 1980s to the present. These trends reflect the history of the fossil fuel combustion and pollution control around each industrial area, respectively. In isolated islands on the Japan Sea, the SCPs trend shows the start of the record in 1950s – 1960s, and gradual increase to the present. The SCPs trend in the northeastern Korea shows increasing upward. On the other hand, the trend in the central Korea showed the peak in a particular depth and decreasing upward. The SCPs trend in China (Beijing, Tsingtao, and Nanjing) showed increasing from 1990s to the present. These results showed SCPs profiles in Japan, Korea, and China has different trend, respectively. Additionally, morphological and chemical characteristics of SCPs observed by SEM/EDS between these countries are different. These findings suggest that most of SCPs in sediments in an industrial city would be derived from the area, indicating that a large proportion of SCPs hardly transport long distance. However few SCPs are found in isolated islands, suggesting that a small portion of SCPs transport long distance (at least 100km). Therefore SCPs profiles in an isolated area play an important role to clarify the long distance transport of materials originated from fossil fuel combustion in past and present in eastern Asia. COSMOGENIC AGE CONSTRAINTS ON THE LAST DEGLACIATION IN SOUTHERN PATAGONIA (49 - 50 S) Daniel Murray. University of Wisconsin-Madison, United States E-mail address: [email protected]
The post-Last Glacial Maximum (LGM) transition reflects global climate dynamics and forcing mechanisms whose influence in the southern midlatitudes remains unclear. Delineating the location and timing of the LGM termination and subsequent climate reversals in the Southern Andes can help quantify past climates in this region. Ice cap expansion and retreat may be linked to the migration of the Southern Westerlies and the Antarctic polar front, and may reflect influences from Antarctica or elsewhere. We examine glacial activity adjacent to the Southern Patagonian Icefield via new 10Be surface exposure dating of a remarkably intact set of moraines, located in little-studied area at 49-50oS, which includes both large outlet valleys and smaller valleys on an interfluve. 10Be ages indicate that the Santa Teresita moraine in the Lago Viedma Valley, the Puerto Bandera moraine in the Lago Argentino Valley (Ackert et al., 2008, Science) and several smaller moraines in the Rio Guanaco Valley were deposited either during, or after, the LGM. Interpretations of the post-LGM sequence hinge strongly on the choice of 10Be production rate. Using a production rate derived from New Zealand, ice retreated in the Rio Guanaco Valley at w18 ka, whereas the Santa Teresita and Puerto Bandera moraines reflect an enlarged ice cap at w13 ka. These findings are consistent with a fullycoupled transient general circulation model that predicts minimal precipitation change but significantly lower temperatures and ELAs w14 ka, followed by warming at w13.5 ka. In this scenario, the Antarctic Cold Reversal was felt as far north as 50oS. Alternatively, the global 10Be production rate (CRONUS) indicates initial ice retreat at w16 ka (Rio Guanaco) and subsequent expansion of the ice cap w11 ka as recorded by the Santa Teresita and Puerto Bandera moraines. This implies glacier retreat after the Younger Dryas interval, and requires an explanation other than hemisphere-scale cooling linked to the ACR. THERMOKARST IN THE GEOLOGICAL RECORD Julian Murton. University of Sussex, United Kingdom E-mail address: [email protected]
Thermokarst denotes the processes, landforms and sediments associated with ablationdusually by thawingdof excess ice in permafrost. Because