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1.
Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation (Q42-1), Qiongshan formation (Q42-2) and Ledong formation (Q43). Spore-pollen analysis shows that there are 6 spore-pollen zones existed, reflecting two cycles of climatic fluctuation from warm-dry to hot-humid. The climax of hot-humid period occurred 6,000-5,000 years B.P.. Based on the 14C dating data of the 38 samples representing the positions of ancient sea level, a breakthrough curve representing the sea level change during the Holocone is obtained, in which , a sea level change caused by tectonic movement is subtracted. Two cycles of rise-drop of sea level with three periods of high sea level were found. The period with the highest sea level is some 6,000-5,000 years B.P.. According to the rise-drop rate of sea level, four periods of the sea level change can be distinguished in the 相似文献
2.
Traditionally, the mid-Holocene in most parts of China was thought to be warmer with higher precipitation, resulting from a strong Asian summer monsoon. However, some recent researches have proposed a mid-Holocene drought interval of millennial-scale in East Asian monsoon margin areas. Thus whether mid-Holocene was dry or humid remains an open issue. Here, Zhuyeze palaeolake, the terminal lake of the Shiyang River Drainage lying in Asian monsoon marginal areas, was selected for reconstructing the details of climate variations during the Holocene, especially mid-Holocene, on the basis of a sedimentological analysis. Qingtu Lake (QTL) section of 6.92m depth was taken from Zhuyeze palaeolake. Multi-proxy analysis of QTL section, including grain size, carbonate, TOC, C/N and δ13C of organic matter, was used to document regional climatic changes during 9-3 cal ka B.P. The record shows a major environmental change at 9.0-7.8 cal ka B.P., attributed to a climate trend towards warmth and humidity. This event was followed by a typical regional drought event which occurred during 7.8-7.5 cal ka B.P. And a warm and humid climate prevailed from 7.5 to 5.0 cal ka B.P., attributed to the warm/humid Holocene Optimum in this region. After that, the climate gradually became drier. Moreover, comparison of the climate record from this paper with the summer insolation at 30°N indicates that the climate pattern reflecting the Asian monsoon changes was caused by insolation change. 相似文献
3.
Analysis of 13 spore-pollen assemblage zones reflecting environmental changes since the later middle Pleistocene showed the
seccession of paleovegetation and the paleogeographic changes in the Bohai Basin and circumjacent area. Paleoclimatic variations
here can obviously be divided into 5 cold and 5 warm periods: 2 cold and 1 warm periods in 200,000–100,000 a B.P.(late middle
Pleistocene) 3 cold and 3 warm periods in 100,000–12,000 a B.P.(late Pleistocene), and 1 warm period since 12,000 a B.P. Late
Pleistocene climate tended to become colder and colder. The coldest period was in the later stage of late Pleistocene, when
the study area was a periglacial zone. The mean annual temperature then was about 10°C lower than it is now. In the middle
stage of late Pleistocene, climate became warm; the mean annual temperature then was about 3–4°C higher than it is now.
By applying principles of climatic stratigraphy, the authors deduced through sporo-pollen analysis, that the boundary between
middle and late Pleistocene should be at 178–181 m, and that between Pleistocene and Holocene should be at 12.8 m. The results
of climatic stratigraphy are consistent with those of magnetic stratigraphy.
This paper was published in Chinese inOceanologica et Limnologia Sinica.18 (3): 253–266, 1987. 相似文献
4.
Based on the δ13C and δ18O fluctuation of lacustrine carbonate, CaCO3 content and sporo-pollen data, a palaeoclimatic history of Bosten Lake during the Holocene has been outlined, several stages
of climatic changes are divided, and the following result es are obtained: (1) Palaeoclimatic changes revealed by carbonate
isotope around Bosten Lake are basically identical with that revealed by other geological records in Xinjiang. Environmental
changes presented apparent Westlies Style model: during cold period, relative humidity increased, δ18O, δ13C and CaCO3 appeared low; but in warm periods, the dry regime aggravated. (2) The temperature reflected by δ18O exist evident features being increase in the late period during the Holocene. Together with the δ13C, pollen and CaCO3 analyses, several cold and warm phases which are of broad regional significance can be identified. The warm peaks occurred
at about 11.0 ka B.P., 9.4 ka B.P., 7.5 ka B.P., 5.0 ka B.P., 3.0 ka B.P. and 2.0 ka B.P.; the cold peaks at 11.5 ka B.P.,
10.5 ka B.P., 8.8 ka B.P., 5.5 ka B.P., 3.3 ka B.P., 2.2 ka B.P. and 1.5 ka B.P.. (3) Several climatic events with the nature
of “abrupt climatic changes” are revealed in the periods of 11.0 ka B.P. −10.5 ka B.P., 9.4 ka B.P. −8.8 ka B.P., 5.5 ka B.P.
−5.0 ka B.P. and 2.0 ka B.P. −1.5 ka B.P.. (4) The results show that carbonate isotopic record of lacustrine sediment in arid
area is very sensitive to climatic changes, and may be play a very important role in understanding the features and mechanism
of palaeoclimatic changes. 相似文献
5.
Sporo-pollen Assemblage and Paleoclimate Events in Shelf Area of the Southern Yellow Sea Since 1.5 ka B.P. 总被引：1，自引：0，他引：1
Based on the authors‘ 1986 to 1994 sporo-pollen assemblage analysis in the southern Yellow Sea area, data from 3 main cores were studied in combination with ^14C, palaeomagnetic and thermoluminescence data. The evolution of the paleoclimate environments in the southern Yellow Sea since 15ka B.P. was revealed that, in deglaciation of the last glacial period, the climate of late glaciation transformed into that of postglaciation, accompanied by a series of violent climate fluctuations. These evolution events happened in a global climate background and related to the geographic changes in eastern China. We distinguished three short-term cooling events and two warming events. Among them, the sporo-pollen assemblage of subzone A1 showed some cold climate features indicating that a cooling event occurred at about 15 - 14ka. B .P. in early deglaciation. This subzone corresponds to the Oldest Dryas. In subzone A3 , many drought-enduring herbal pollens and some few pollens of cold-resistant Picea, Abies, etc. were found, which indicated that a cooling event, with cold and arid climate, occurred at about 12- 11ka. B.P. in late deglaciation. This subzone corresponds to the Younger Dryas. The sporo-pollen assemblage of zone B showed warm and arid climate features in postglaciation. Although the assemblage of subzone B2 indicated a cold and arid climate environment, the development of flora in subzone B2 climate was less cold than that in A3 . Subzone B2 indicated a cooling event which occurred at about 9ka B.P. in early Holocene. Subzone A2, with some distinct differences from subzone A1 and A3 , indicated a warming event which occurred at 14 - 13ka. B.P. and should correspond to a warming fluctuation. The sporo-pollen assemblage of zone C showed features of warm-moist flora and climate, and indicated a warming event which universally occurred along the coast of eastern China at 8 - 3ka B.P. in middle Holocene, and its duration was longer than that of any climate events mentioned above. This period was climatic optimum and belonged to an altithermal period in postglaciation. 相似文献
6.
This paper presents the study on two continuous glacio-lacustrine sedimentary deposits, Laotanfang (3 597 m) and Shibantang (3 689 m) located on the southern and northern sides of Hulifang peak in Yunan, China. Environmental change indexes are constructed for each deposit, based on grain size, geochemical and pollen analysis, environmental magnetic susceptibility, and 14C dating. The study of climatic environmental change since the Holocene epoch in this region shows that the climate fluctuated at different stages during the early Holocene, that is, the climate was cool and wet during 8 4-7 7 ka, cold and wet during 7 7-6 5 ka, cold and dry during 6 5-4 7 ka, cool and wet during 4 7-2 1 ka, warm and wet during 2 1-1 0 ka, and warmer and wet since 1 ka. These findings reflect the overlapping influences of the southwest and southeast monsoons in different times during the Holocene in the north part of southwestern China are in accord with other Holocene climate change models in this part of China. 相似文献
7.
Palynological record of paleovegetation change during holocene at North tumd plain in Inner Mongolia, China 总被引：3，自引：0，他引：3
I~are~orsruDVThemiddleinnerMongoliaissituatedintherearpartoftheeasternAsianmonsonzone,itissensitivetotheclimatechange,thereforeitsenvironmentchangeintheHOIOcenehasbeenPaidattentiontobythescholarsofpaleoclimateandpal~nvirorunent.Wedidhighr~lutionPOllenanalysisonapeatprofileinpluvialfan,whichwaslocated3kmtothenorthOfQaSq,theheadquarteroftheTumdBanner,InnerMongolia,withaltitudeof1000malerssealevel.Theaverageannualtemperaturewas5.6t,annualprecipitation300--450rum,theclimatewascontinentaland… 相似文献
8.
On the origin of rice agriculture in southern China and its propagation in East Asia 总被引：1，自引：0，他引：1
Zhenguo Huang 《中国地理科学(英文版)》1994,4(4):289-294
Based on the archaeological rice cultivation with the14C dating of about 4000–5000 a B.P. the author holds that the plain at the lower reaches of the Changjiang (Yangtze) River
is one origin of rice cultivation in Asia and the other is Allahabad of India. The propagation of ancient rice cultivation
in China can be divided into three stages, namely 4000–3000, 2635–2420 and about 1000 a B.P. It is inferred that there were
two ways for propagating rice cultivation from China to Japan. One was from lower reaches of Changjiang River to Kyushu by
sea way and the other was from Shandong Peninsula to southern Korea and then to Kyushu. The age of propagating rice cultivation
into Vietnam from South China is about 1000 a B.P. Being influenced by climatic changes since about 5000 a B.P. the propagation
of rice cultivation was stagnated for two times at least, for example, the three warm climatic stages and the two cold stages
were quite in correspondence with the propagation and stagnation stages of rice cultivation, respectively, in China. During
the ancient times the development of paddy rice was directive related to the fluctuation of sea level which is in keeping
with the climatic changes. 相似文献
9.
Information on the palaeoenvironment from Late Pleistocene to Holocene in northwestern Yannan Plateau has been deduced from a study of a 28.81m-long core taken from Napahai Lake.The results from Relative Brightness In-dex(RBI) as well as those from the lithological analyses of bulk sediments,total organic carbon and granulometric analy-ses have been used to reconstruct the environmental and climatic evolution of the area.The ages were provided by three ^14C datings.The record suggested a climate fluctuation between warm-dry and cool-wet from ca.57 to 32ka B.P.which led a shallowing and swamping of the lake.The water level again increased quickly at ca.32ka B.P.,reached itˊs peak during LGM(Last Glacial Maximum,ca.18-20kaB.P.)and remained relative high until ca.15kaB.P.The high wa-ter level at LGM is attributed to cold-wet conditions.The area experienced an abrupt and unstable climatic changes dur-ing the transition period form 15 to 10ka B.P.with a dominated littoral environment.Awarm-dry climate led to the contrac-tion of the lake during the Holocene and reed-swamps became dominant..After a minor wet-cool pulse during the Late Holocene,the modern climate became to be established. 相似文献
10.
To decipher the sedimentary evolution and environmental changes since the late Last Deglaciation, two gravity cores were analyzed from the western North Yellow Sea (NYS). The two cores (B-L44 and B-U35) were sampled for grain size, clay minerals, detrital minerals, and 14C dating. They are comparable in lithofaies, and the observed succession was divided into four depositional units based on lithology and mineral assemblages, which recorded the postglacial transgression. Depositional unit 4 (DU 4) (before 11.5 ka) was characterized with enrichment in sand, and was interpreted as nearshore deposits in shallow water during the Younger Dryas Event. DU 3 (11.5-9.6 ka) displayed a fining-upward succession composed of sediments from local rivers, such as the Huanghe (Yellow) River, and from coastal erosion, which clearly were related to the Early Holocene transgression. Stable muddy deposition (DU 2) in NYS began to form at about 9.6 ka, which received direct supply of fine materials from the Shandong subaqueous clinoform. It is believed that the Yellow Sea circulation system played a major role in controlling the formation of fine sediment deposition in DU 1 (after 6.4 ka) after the sea level maximum. 相似文献
11.
Isotopic evidence for holocene climatic changes in Bosten Lake, Southern Xinjiang, China 总被引：2，自引：0，他引：2
ＩＳＯＴＯＰＩＣＥＶＩＤＥＮＣＥＦＯＲＨＯＬＯＣＥＮＥＣＬＩＭＡＴＩＣＣＨＡＮＧＥＳＩＮＢＯＳＴＥＮＬＡＫＥ,ＳＯＵＴＨＥＲＮＸＩＮＪＩＡＮＧ,ＣＨＩＮＡＺｈｏｎｇＷｅｉ（钟巍）ＸｉｏｎｇＨｅｉｇａｎｇ（熊黑钢）ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐ... 相似文献
12.
CHENG Jie ZHANG Xujiao TIAN Mingzhong YU Wenyang and YU Jiangkuan China University of Geosciences Beijing China TANG Dexiang Institute of Process Engineering Chinese Academy of Sciences Beijing China YUE Jianwei Institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing China 《山地科学学报》2005,2(3):193-201
Introduction The Tibetan Plateau, located in west China, was uplifted during the Cenozoic and became the most youthful plateau in the world. Some researches have also shown that it started to develop into the cryosphere in the beginning of the Middle Pleistocene and became one of the three global cryospheres (two other cryospheres being the Artic and the Antarctic) (SHI et al. 1996). Because of the cryosphere development in the Tibetan Plateau, many periglacial and permafrost geomorpholog… 相似文献
13.
On the basis of lacustrine sedimentary profile of Ebinur Lake, sequences of evolution of paleoclimate and paleoenvironment
in Ebinur Lake area have been rebuilt by analysing the sedimentary stratigraphy, bio-stratigraphy and geochemistry as well
as the chronological records. The results show that, during the last 10 ka years, the general change trends of the paleoclimate
in E-binur Lake area can be divided into three stages: (1) 10. 2 – 8.3 ka B. P., a warm-cool dry climate stage; (2) 8.3–3.5
ka B. P., a warmer moist climate stage (specially, 7.3–6.4 ka B. P., a relatively stable humid temperate stage); (3) 3.5 ka
B. P. —present, adraught temperate climate stage, similar to the present climate. In addition, there existed clearly several
times of secondary undulations of dry-humid climate, i.e. 8.3 ka and 7.3 ka for dry climate 相似文献
14.
Although the mid-late Holocene cold and dry event about 4000 years ago(the 4 ka event) has been observed almost globally, it was most prominent in terrestrial climate proxies from the lower latitudes. Here we evaluate the oceanic response to this event in terms of a Holocene sea surface temperature(SST) record reconstructed using the K'37U index for Core B3 on the continental shelf of the East China Sea. The record reveals a large temperature drop of about 5℃ from the mid-Holocene(24.7℃ at 5.6 ka) to the 4 ka event(19.2℃ at 3.8 ka). This mid-late Holocene cooling period in Core B3 correlated with(i) decreases in the East Asia summer monsoon intensity and(ii) the transition period with increased El Nino/Southern Oscillation activities in the Equatorial Pacific. Our SST record provides oceanic evidence for a more global nature of the mid-late Holocene climate change, which was most likely caused by a southward migration of the Intertropical Converge Zone in response to the decreasing summer solar insolation in the Northern Hemisphere. However, the large SST drop around Core B3 indicates that the mid-late Holocene cooling was regionally amplified by the initiation/strengthening of eddy circulation/cold front which caused upwelling and resulted in additional SST decrease. Upwelling during the mid-late Holocene also enhanced with surface productivity in the East China Sea as reflected by higher alkenone content around Core B3. 相似文献
15.
王红亚 《中国地理科学(英文版)》1999,9(3):250-257
１ ＩＮＴＲＯＤＵＣＴＩＯＮＲｕｎｏｆｆｉｓｄｅｆｉｎｅｄａｓｔｈｅｗａｔｅｒｔｈａｔｄｒａｉｎｓｆｒｏｍｔｈｅｌａｎｄｉｎｔｏｃｒｅｅｋｓａｎｄｒｉｖｅｒｓ（Ｌａｎｇｂｅｉｎｅｔａｌ．,１９４９）ａｎｄｔｈｕｓａｖｅｒｙｉｍｐｏｒｔａｎｔｈｙｄｒｏｌｏｇｉｃａｌｐａｒａｍｅｔｅｒｄｅｓｃｒｉｂｉｎｇｑｕａｎｔｉｔｙｓｔａｔｕｓｏｆｓｕｒｆａｃｅｗａｔｅｒ．Ｉｔｉｓｌａｒｇｅｌｙａｆｕｎｃｔｉｏｎｏｆｔｈｅｃｌｉｍａｔｉｃｃｏｎｄｉｔｉｏｎｓｔｈｏｕｇｈｉｔｉｓａｌｓｏａｆｆｅｃｔｅｄｂｙｖｅ… 相似文献
16.
The Huanghe (Yellow) River, with annual sediment discharge about 11 ×108tons, contributes about 17% of the fluvial sediment discharge of world's 21 major rivers to the ocean because its middle reaches flow across the great Loess Plateau of China. Sediment discharge of the Huanghe River has a widespread and profound effect on sedimentation of the sea. The remarkable shift of its outlet in 1128-1855 A.D. to the South Yellow Sea formed a large subaqueous delta and provided the substrate for an extensive submarine ridge field.The shift of its outlet in the modern delta every 10 years is the main reason why with an extremely heavy sediment input and a micro- tidal environment, the Huanghe River has not succeeded in building a birdfoot delta like the Mississippi. The Huanghe River has consistently brought heavy sediment input to sea at least since 0.7 myr.B.P. Paleochannels, paleosols, cheniers and fossils on the sea bottom indicate that the Yellow Sea was exposed during the late Quaternary glacial low-sea l 相似文献
17.
Biomarker evidence for paleoenvironmental changes in the southern Yellow Sea over the last 8200 years 总被引：2，自引：0，他引：2
Previous studies have indicated that the Yellow Sea underwent significant environmental changes during the Holocene, but many questions remain concerning the timing of the establishment of the modern circulation system, which would have major implications for the Yellow Sea ecosystem and carbon cycle. In this study, marine and terrestrial biomarkers were analyzed in Core YE-2 from a muddy area in the southern Yellow Sea to reconstruct Holocene environmental and phytoplankton community change. The content of three individual marine phytoplankton biomarkers (alkenones, brassicasterol and dinosterol) all display a similar trend, and their total contents during the early Holocene (362 ng/g) were lower than those during the mid-late Holocene (991 ng/g). On the other hand, the contents of terrestrial biomarkers (C27+C29+C31n-alkanes) during the early Holocene (1 661 ng/g) were about three times higher than those during the mid-late Holocene (499 ng/g). Our biomarker results suggest that the modern circulation system of the Yellow Sea was established by 5-6 ka, and resulted in higher marine productivity and lower terrestrial organic matter inputs. Biomarker ratios were used to estimate shifts in phytoplankton community structure in response to mid-Holocene (5-6 ka) environmental changes in the Yellow Sea, revealing a transition from a dinoflagellate-diatom dominant community structure during the early Holocene to a coccolithophore-dominant community structure during the mid-late Holocene. 相似文献
18.
A synthesis of Holocene pollen records from the Tibetan Plateau shows the history of vegetation and climatic changes during the Holocene. Palynological evidences from 24 cores/sections have been compiled and show that the vegetation shifted from subalpine/alpine conifer forest to subalpine/alpine evergreen sclerophyllous forest in the southeastern part of the plateau; from alpine steppe to alpine desert in the central, western and northern part; and from alpine meadow to alpine steppe in the eastern and southern plateau regions during the Holocene. These records show that increases in precipitation began about 9 ka from the southeast, and a wide ranging level of increased humidity developed over the entire of the plateau around 8-7 ka, followed by aridity from 6 ka and a continuous drying over the plateau after 4-3 ka. The changes in Holocene climates of the plateau can be interpreted qualitatively as a response to orbital forcing and its secondary effects on the Indian Monsoon which expanded northwards 相似文献
19.
STUDY OF OKINAWA TROUGH SEDIMENTATION RATES AND PALEOENVIRONMENT BASED ON URANIUM SERIES ISOTOPE 总被引：1，自引：0，他引：1
Spectrometry of ~(238)U, ~(234)U, ~(230)Th and, ~(232)Th in three Okinawa Trough cores showed that, based on the~(230)Th/~(232)Th activity ratio, the sedimentation rates were about 2.5 cm/ka, 2.8 cm/ka and 8.5 cm/ka respectivelyduring the Holocene and about 20.1 cm/ka, 12.29 cm/ka, 8.8 cm/ka and 12.6 cm/ka respectively during theWurm glacial. To examine the past global climatic and oceanographic changes, the stable oxygen isotopesδ~(18)O and CaCO_3 were measured. The Th content and Th/U ratio showed that variations of terrigenous materialinput from the continental shelf were associated with glacial and interglacial changes and sea level 相似文献
20.
THE PRELIMINARY STUDY ON POSSIBLE SCENARIOS OF FLOOD AND DROUGHT IN CHINA IN THE CASE OF GLOBAL WARMING 总被引：1，自引：0，他引：1
ＴＨＥ ＰＲＥＬＩＭＩＮＡＲＹ ＳＴＵＤＹ ＯＮ ＰＯＳＳＩＢＬＥ ＳＣＥＮＡＲＩＯＳ ＯＦ ＦＬＯＯＤ ＡＮＤ ＤＲＯＵＧＨＴ ＩＮ ＣＨＩＮＡ ＩＮ ＴＨＥ ＣＡＳＥ ＯＦ ＧＬＯＢＡＬ ＷＡＲＭＩＮＧ ＣｈｅｎＪｉａｑｉ（陈家其）（Ｎａｎｊｉｎ... 相似文献