- Email: [email protected]
paleoclimatic and paleoenvironmental evolution since the late glacial epoch in jianghuai plain
Abstracts / Quaternary International 279-280 (2012) 346–461
B.P.) is characterized by the establishment of trapezoid industries associated with edge-ground stone axes. These industries are considered to have been derived from scraper/flake industries lacking blade techniques, which represent the first prevailing lithic industries. X-ray fluorescence analysis has revealed that the discovery and exploitation of obsidian sources located at high mountainous areas (1,200-2,000 m) and a Pacific island (Kozu island, >60 km away from the mainland) date back to as early as the initial Upper Palaeolithic. These explorations were achieved in the course of comprehensive surveys for natural resources conducted by the first immigrants to the archipelago. With the beginning of the early Upper Palaeolithic (35-30 kyr cal. B.P.), blade techniques, elaborate grinding methods for axe using whetstones, and the management of non-local raw materials were established. Although biology of the immigrants is unknown in terms of fossil record, all archaeological evidence indicates that the first immigrants reaching the Japanese Archipelago from the Asian continent were behaviorally modern humans. The movement has been rightly connected to the wave of modern human dispersal into the eastern part of Eurasia. RECONSTRUCTION OF THE EAST ASIAN SUMMER MONSOONAL VARIABILITY IN THE NORTHERN JAPAN SINCE THE LAST DEGLACIATION BASED ON d13C TIME SERIES OF PEAT CELLULOSE Tetsuya Shinozaki. University of Tsukuba, Japan E-mail address: [email protected]
The East Asian summer monsoon (EASM) is one of the most important components that influence the East Asian climate. People living around East Asia depend on food supply supported by EASM rainfall, however, monsoonal rainfall fluctuations often derive devastating floods and/or drought. A critical question is whether, and how, a rapid and significant change in global climate might affect the monsoon system. Stable carbon isotope ratio of peat cellulose (d13Ccellulose) is used as a proxy indicator for precipitation amount. EASM variability in northern Japan, associated continental water cycle, was investigated using d13Ccellulose. Here, we present East Asian monsoon variability and their linkages with global climate system during the last deglaciation in the northeast Japan, using peat cellulose d13C of high time resolution peat archive. We used 8.8 m length peat core corrected from the Tashiro bog, northern Japan. We conducted total 53 14C measurements, and found the core bottom reached to 15.5 ka. We discussed about peat cellulose extractions to investigate more suitable 14C chronologies because peat contains various organic matrixes with old carbon contamination. The results of d13Ccellulose showed clear variations with higher values during warm periods (B/A, PB) and lower values during cold periods (YD, 8.2 ka), suggesting that it is wet summer in the cold periods and dry in the warm periods. Similar patterns of d13Ccellulose were reported in Hani peat bog, at northeast China (Hong et al., 2005). On the other hand, these results had anti-phase synchronization at Tibet significantly influenced with Indian monsoon (Hong et al., 2003). Our high-resolution d13Ccellulose records highly coincided with EASM variations during the abrupt climate changes, suggesting that the strong linkages with global climate system. PALEOCLIMATIC AND PALEOENVIRONMENTAL EVOLUTION SINCE THE LATE GLACIAL EPOCH IN JIANGHUAI PLAIN Qiang Shu. College of Geography Science, Nanjing Normal Unive, China E-mail address: [email protected]
Abstract: The Jianghuai Plain located not only in the margin area of Chinese important climate separatrixdQinling -Huaihe River but also in the Monsoon triangle Area of china, under the influences of the East Asian monsoon, very important in recording the East Asian monsoon changes. A sediment core from Jianghuai plain was chosen for the study. Base on the analyses of chronology, magnetic susceptibility and Grain Size of YZQ Core Sediments form Jianghuai Plain, the climate history of the jianghui plain during the last 19230 cal a B.P. was revealed as cool and dry (19230-14 150cal aBP) warm and wet(14150-12950 cal aBP) cool and dry(1295011290 cal aBP) warm and wet(11290-7450cal aBP) temperate and
447
dry(7450-4950cal aBP) warm and wet(4950-1510 cal aBP). In addition, the indexes also recorded several climate events, Older Dryas, Younger Dryas, 8250 cal aBP and 3500-2500 cal aBP events are obviously. Most signigicantly, the similarity which can be observed among the fluctuation of climate proxies in this paper, the GULIYA ice core d18O record, the Greenland GISP2 ice coreCH4 record and the Sanbao/Hulu's stalagmite d18O record shows that climate change of the studied area may have global background, and on the other hand, it also incarnates evident regional characteristics. GROUND PENETRATING RADAR (GPR) STUDIES ALONG THE SW KACHCHH COAST, WESTERN INDIA: IMPLICATIONS IN RECONSTRUCTING HIGH ENERGY EVENT HISTORY S.B. Shukla. Department of geology, The M.S. University of Baro, India E-mail address: [email protected]
The Kachchh coast is the northern flank of Gulf of Kachchh – one of the largest macrotidal regime in southeast Asia. The South-West coast of Kachchh coastline is about 100km long and is sandy in nature, comprising of series of barrier ridges and dunes along its length. The coastline is ideal for evaluating the application of ground penetrating radar as it is an excellent non-destructive technique in studying the shallow subsurface architecture of sedimentary bodies. Totally four sites were studied where traverses across the coastline covering these various landforms were collected using GSSI SIR-20 GPR system with 200MHz monostatic shielded antenna. The raw GPR data were processed with Radan 5.0 software and various sedimentary body related radar facies bounded by several radar bounding surfaces were interpreted. Major radar facies identified using GPR were Beach Ridge facies (Br) with parallel concave downward sea ward dipping reflectors, Washover facies (Wo) with concave downward tangential and land ward inclined reflectors and Coastal dune facies (Cd) with sub-parallel cross bedded reflectors. The Kachchh coastline, as evidence by the GPR profiles, is characterized by beach-ridge-dune complex along its entire length. The thickness of dunes and beach ridges increases at eastern end (about 1km), which is due to littoral drift of sediments in longshore currents. The conspicuous presence of washover deposits on the landward side of these beach ridges and coastal dunes is symptomatic to the region being prone to high energy coastal events (storms/tsunamis). The truncations of these washover deposits over coastal dunes and beach ridges is quite fascinating in terms of the reconstructing the frequency of these high energy events in the region. GPR proves to be very useful tool in aiding the study to delineate the subsurface coastal sedimentary body geometry, which has immense implications in evaluating the frequency of these high energy coastal events of inundation. THE CHRONOLOGY OF THE LAST DEGLACIATION FROM TWO NEW ZEALAND VALLEYS AND THE CONTRASTING ROLES OF CLIMATE AND GEOMORPHOLOGY James Shulmeister. University of Queensland, Australia E-mail address: [email protected]
We present Be-10 and Al-26 chronologies from the paleo-Rakaia glacier and the Clearwater lobe of the Rangitata glacier focussing on the transition from the last glaciation maximum (LGM) to the Holocene. From the Rakaia we demonstrate that the local glacial maximum preceded the global LGM by several thousand years at c. 25 ka. Over the succeeding 12,000 years the glacier retreated only about 10 km and although undated, geomorphic evidence suggests a continued steady retreat after this time. The Clearwater lobe of the Rangitata glacier provides the most detailed LGIT record from any New Zealand glacier because it the valley was protected from significant meltwater flow during the deglaciation. Between 16.4 ka and 13.7 ka the Clearwater ice lobe retreated only 12 km producing 23 closely spaced recessional ice positions. The geomorphology and chronology are categorical in demonstrating that no significant re-advance can have occurred during this period. The inboard termination of the record occurs where the Clearwater valley drops into the main Rangitata Valley and should not be interpreted as the start of the more significant retreat. We highlight that uncertainties in isotope production rates and other elements
B.P.) is characterized by the establishment of trapezoid industries associated with edge-ground stone axes. These industries are considered to have been derived from scraper/flake industries lacking blade techniques, which represent the first prevailing lithic industries. X-ray fluorescence analysis has revealed that the discovery and exploitation of obsidian sources located at high mountainous areas (1,200-2,000 m) and a Pacific island (Kozu island, >60 km away from the mainland) date back to as early as the initial Upper Palaeolithic. These explorations were achieved in the course of comprehensive surveys for natural resources conducted by the first immigrants to the archipelago. With the beginning of the early Upper Palaeolithic (35-30 kyr cal. B.P.), blade techniques, elaborate grinding methods for axe using whetstones, and the management of non-local raw materials were established. Although biology of the immigrants is unknown in terms of fossil record, all archaeological evidence indicates that the first immigrants reaching the Japanese Archipelago from the Asian continent were behaviorally modern humans. The movement has been rightly connected to the wave of modern human dispersal into the eastern part of Eurasia. RECONSTRUCTION OF THE EAST ASIAN SUMMER MONSOONAL VARIABILITY IN THE NORTHERN JAPAN SINCE THE LAST DEGLACIATION BASED ON d13C TIME SERIES OF PEAT CELLULOSE Tetsuya Shinozaki. University of Tsukuba, Japan E-mail address: [email protected]
The East Asian summer monsoon (EASM) is one of the most important components that influence the East Asian climate. People living around East Asia depend on food supply supported by EASM rainfall, however, monsoonal rainfall fluctuations often derive devastating floods and/or drought. A critical question is whether, and how, a rapid and significant change in global climate might affect the monsoon system. Stable carbon isotope ratio of peat cellulose (d13Ccellulose) is used as a proxy indicator for precipitation amount. EASM variability in northern Japan, associated continental water cycle, was investigated using d13Ccellulose. Here, we present East Asian monsoon variability and their linkages with global climate system during the last deglaciation in the northeast Japan, using peat cellulose d13C of high time resolution peat archive. We used 8.8 m length peat core corrected from the Tashiro bog, northern Japan. We conducted total 53 14C measurements, and found the core bottom reached to 15.5 ka. We discussed about peat cellulose extractions to investigate more suitable 14C chronologies because peat contains various organic matrixes with old carbon contamination. The results of d13Ccellulose showed clear variations with higher values during warm periods (B/A, PB) and lower values during cold periods (YD, 8.2 ka), suggesting that it is wet summer in the cold periods and dry in the warm periods. Similar patterns of d13Ccellulose were reported in Hani peat bog, at northeast China (Hong et al., 2005). On the other hand, these results had anti-phase synchronization at Tibet significantly influenced with Indian monsoon (Hong et al., 2003). Our high-resolution d13Ccellulose records highly coincided with EASM variations during the abrupt climate changes, suggesting that the strong linkages with global climate system. PALEOCLIMATIC AND PALEOENVIRONMENTAL EVOLUTION SINCE THE LATE GLACIAL EPOCH IN JIANGHUAI PLAIN Qiang Shu. College of Geography Science, Nanjing Normal Unive, China E-mail address: [email protected]
Abstract: The Jianghuai Plain located not only in the margin area of Chinese important climate separatrixdQinling -Huaihe River but also in the Monsoon triangle Area of china, under the influences of the East Asian monsoon, very important in recording the East Asian monsoon changes. A sediment core from Jianghuai plain was chosen for the study. Base on the analyses of chronology, magnetic susceptibility and Grain Size of YZQ Core Sediments form Jianghuai Plain, the climate history of the jianghui plain during the last 19230 cal a B.P. was revealed as cool and dry (19230-14 150cal aBP) warm and wet(14150-12950 cal aBP) cool and dry(1295011290 cal aBP) warm and wet(11290-7450cal aBP) temperate and
447
dry(7450-4950cal aBP) warm and wet(4950-1510 cal aBP). In addition, the indexes also recorded several climate events, Older Dryas, Younger Dryas, 8250 cal aBP and 3500-2500 cal aBP events are obviously. Most signigicantly, the similarity which can be observed among the fluctuation of climate proxies in this paper, the GULIYA ice core d18O record, the Greenland GISP2 ice coreCH4 record and the Sanbao/Hulu's stalagmite d18O record shows that climate change of the studied area may have global background, and on the other hand, it also incarnates evident regional characteristics. GROUND PENETRATING RADAR (GPR) STUDIES ALONG THE SW KACHCHH COAST, WESTERN INDIA: IMPLICATIONS IN RECONSTRUCTING HIGH ENERGY EVENT HISTORY S.B. Shukla. Department of geology, The M.S. University of Baro, India E-mail address: [email protected]
The Kachchh coast is the northern flank of Gulf of Kachchh – one of the largest macrotidal regime in southeast Asia. The South-West coast of Kachchh coastline is about 100km long and is sandy in nature, comprising of series of barrier ridges and dunes along its length. The coastline is ideal for evaluating the application of ground penetrating radar as it is an excellent non-destructive technique in studying the shallow subsurface architecture of sedimentary bodies. Totally four sites were studied where traverses across the coastline covering these various landforms were collected using GSSI SIR-20 GPR system with 200MHz monostatic shielded antenna. The raw GPR data were processed with Radan 5.0 software and various sedimentary body related radar facies bounded by several radar bounding surfaces were interpreted. Major radar facies identified using GPR were Beach Ridge facies (Br) with parallel concave downward sea ward dipping reflectors, Washover facies (Wo) with concave downward tangential and land ward inclined reflectors and Coastal dune facies (Cd) with sub-parallel cross bedded reflectors. The Kachchh coastline, as evidence by the GPR profiles, is characterized by beach-ridge-dune complex along its entire length. The thickness of dunes and beach ridges increases at eastern end (about 1km), which is due to littoral drift of sediments in longshore currents. The conspicuous presence of washover deposits on the landward side of these beach ridges and coastal dunes is symptomatic to the region being prone to high energy coastal events (storms/tsunamis). The truncations of these washover deposits over coastal dunes and beach ridges is quite fascinating in terms of the reconstructing the frequency of these high energy events in the region. GPR proves to be very useful tool in aiding the study to delineate the subsurface coastal sedimentary body geometry, which has immense implications in evaluating the frequency of these high energy coastal events of inundation. THE CHRONOLOGY OF THE LAST DEGLACIATION FROM TWO NEW ZEALAND VALLEYS AND THE CONTRASTING ROLES OF CLIMATE AND GEOMORPHOLOGY James Shulmeister. University of Queensland, Australia E-mail address: [email protected]
We present Be-10 and Al-26 chronologies from the paleo-Rakaia glacier and the Clearwater lobe of the Rangitata glacier focussing on the transition from the last glaciation maximum (LGM) to the Holocene. From the Rakaia we demonstrate that the local glacial maximum preceded the global LGM by several thousand years at c. 25 ka. Over the succeeding 12,000 years the glacier retreated only about 10 km and although undated, geomorphic evidence suggests a continued steady retreat after this time. The Clearwater lobe of the Rangitata glacier provides the most detailed LGIT record from any New Zealand glacier because it the valley was protected from significant meltwater flow during the deglaciation. Between 16.4 ka and 13.7 ka the Clearwater ice lobe retreated only 12 km producing 23 closely spaced recessional ice positions. The geomorphology and chronology are categorical in demonstrating that no significant re-advance can have occurred during this period. The inboard termination of the record occurs where the Clearwater valley drops into the main Rangitata Valley and should not be interpreted as the start of the more significant retreat. We highlight that uncertainties in isotope production rates and other elements