The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive character...The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive characteristics and are a critical archive for understanding climatic changes in the coastal areas of East Asia. The ages of the late Quaternary aeolian sand dunes from Haitan Island in the coastal area of South China are still in debate. In this study, three sets of marine terraces were identified in the northern region of Haitan Island. Aeolian dune sands are well preserved on the top of these terraces. Quartz Optically Stimulated Luminescence dating and the distribution of the formation ages demonstrated that the palaeo-dunes are deposits from the middle-late period of the Late Pleistocene(Q_3^(2-3)). The period may be divided into three stages, 100-90 ka, 70-60 ka, and 40-20 ka, in which the palaeo-dunes of the first two stages are more widespread and were formed separately during a low-sea level period of the Marine Isotope Stages 5 b and 4. Several depositional palaeo-flood event records were preserved during the last stage due to the increasing gradient of mountain gullies formed during the Last Glacial Maximum.展开更多
Coastal dunes are a common geomorphic type in sandy coastal zones.They are a record of the coupled evolutionary processes of the wind and ocean waves.Many coastal dune fields have developed on the east coast of Fujian...Coastal dunes are a common geomorphic type in sandy coastal zones.They are a record of the coupled evolutionary processes of the wind and ocean waves.Many coastal dune fields have developed on the east coast of Fujian China and now occur as widespread typical coastal aeolian sand landforms on the Liuao Peninsula,Gulei Peninsula and Dongshan Island,but it is difficult to evaluate the dynamic geomorphologic process of sandy coast due to the lack of systematic and accurate chronological data.In this study,we selected the Hutoushan(HTS)aeolian dune on the Liuao Peninsula as the research object.Optical dating and grain-size analysis were applied to sand samples from the aeolian sequence of a profile of the HTS dune.The results show that the ages of seven samples of this profile were in the range of 37.8–0.19 ka from 4.0 to 0.2 m deep.These correspond to the Marine Isotope Stage 3(MIS3),abrupt climatic change events of 4.2 and 1.1 ka and the Little Ice Age(LIA),respectively.These samples displayed evidence of a longer-term climate trend in this area.The period of formation of this coastal aeolian dune corresponds to a cold and arid climate associated with the East Asia Winter Monsoon(EAWM).Periods of dune fixation and rubification are evidence of a hot and humid climate.Mobilization and stabilization of the aeolian dune is an important characteristic of the coastal evolution in South China since the late Pleistocene.展开更多
The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi ...The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi Mountain of South China,represents the first discovered and scientifically excavated Middle Palaeolithic site in the Fujian Province.This site is of considerable significance for studying the diffusion and cultural connotation of early Homo sapiens in southern China.In this study,we present optically stimulated luminescence(OSL)ages obtained from medium-grained quartz collected at the LPS.The single-aliquot regenerative-dose measurements of red soil deposits collected at the same site yielded internally and stratigraphically consistent ages and similar errors,indicating a potential ability of the technique,and also reflecting the influence of various sedimentary facies on the test results.Our results indicate that the 38–63µm quartz grains were generally partially-bleached and had large values of over-dispersion in the palaeo-reticulated laterites of west Fujian.Some samples yielded unsatisfactory results,suggesting that the degree of bleaching of diluvial and alluvial deposits should be properly assessed before dating.We did not detect any enrichment/depletion of U,Th and radioactive disequilibrium.The effect of chemical weathering on the dose rate estimation was negligible.Therefore,we used a central age model and the maximum age model to calculate the age of two samples,respectively,and the minimum age model to calculate the ages of the rest of the samples.The OSL ages of the samples ranged from 27.09±2.30 ka to 54.65±7.39 ka for the 38–63µm quartz size fraction,and roughly corresponded to the Marine Isotope Stage 3.In addition,three ages out of five are based on the calculation of minimum ages in this research,which needs to be further verified by other dating methods.展开更多
The Aeolian foredunes in the southern coast of China are records of paleoenvironmental changes for marine monsoon region. Intensive studies have been conducted to decipher their formation and paleoenvironmental implic...The Aeolian foredunes in the southern coast of China are records of paleoenvironmental changes for marine monsoon region. Intensive studies have been conducted to decipher their formation and paleoenvironmental implications in which chronology played a key role. However, robust dating results are still limited due to the scarcity of organic materials for radiocarbon and the limited application of quartz optically stimulated luminescence(OSL). Here, we collected 11 OSL samples and 140 grainsize samples from the Changle section with a thickness of 7 m from a coastal foredune in Fujian Province. The dating results indicated that the section spanned a time period from 0.32±0.04 ka(depth of 700 cm) to 0.18±0.02 ka(depth of 80 cm), after removal of age outliers. According to the OSL ages and sedimentary structural characteristics, the section could be divided into two stages, i.e. the stable accumulation period with an age range of 0.32-0.18 ka from the depth of 700 cm to 80 cm, and the activation period above the depth of 60 cm, at which the dune erosion was retained. The foredune development due to increased transport of dune sediment at the top part of the section was the result of recent human activities.Inside the foredunes, normal cross-bedding was generated by seasonal changes in wind direction.Seasonal changes in the wind direction were the primary cause for various sedimentary bedding within the dunes.展开更多
基金funded by the National Natural Science Foundation of China (Grants Nos. 41301012, 41771020 and U1405231)Natural Science Foundation of Fujian (Grant No. 2018R1034-5)Innovation Research Team Fund of Fujian Normal University (Grant No. IRTL1705)
文摘The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive characteristics and are a critical archive for understanding climatic changes in the coastal areas of East Asia. The ages of the late Quaternary aeolian sand dunes from Haitan Island in the coastal area of South China are still in debate. In this study, three sets of marine terraces were identified in the northern region of Haitan Island. Aeolian dune sands are well preserved on the top of these terraces. Quartz Optically Stimulated Luminescence dating and the distribution of the formation ages demonstrated that the palaeo-dunes are deposits from the middle-late period of the Late Pleistocene(Q_3^(2-3)). The period may be divided into three stages, 100-90 ka, 70-60 ka, and 40-20 ka, in which the palaeo-dunes of the first two stages are more widespread and were formed separately during a low-sea level period of the Marine Isotope Stages 5 b and 4. Several depositional palaeo-flood event records were preserved during the last stage due to the increasing gradient of mountain gullies formed during the Last Glacial Maximum.
基金supported by National Natural Science Foundation of China (Grant Nos. 41301012, 41771020)Special Research of Public Welfare Scientific Research Institutes of Fujian Province, China (Grant No. 2018R1034-5)the Innovation Research Team Fund of Fujian Normal University (Grant No. IRTL1705)
文摘Coastal dunes are a common geomorphic type in sandy coastal zones.They are a record of the coupled evolutionary processes of the wind and ocean waves.Many coastal dune fields have developed on the east coast of Fujian China and now occur as widespread typical coastal aeolian sand landforms on the Liuao Peninsula,Gulei Peninsula and Dongshan Island,but it is difficult to evaluate the dynamic geomorphologic process of sandy coast due to the lack of systematic and accurate chronological data.In this study,we selected the Hutoushan(HTS)aeolian dune on the Liuao Peninsula as the research object.Optical dating and grain-size analysis were applied to sand samples from the aeolian sequence of a profile of the HTS dune.The results show that the ages of seven samples of this profile were in the range of 37.8–0.19 ka from 4.0 to 0.2 m deep.These correspond to the Marine Isotope Stage 3(MIS3),abrupt climatic change events of 4.2 and 1.1 ka and the Little Ice Age(LIA),respectively.These samples displayed evidence of a longer-term climate trend in this area.The period of formation of this coastal aeolian dune corresponds to a cold and arid climate associated with the East Asia Winter Monsoon(EAWM).Periods of dune fixation and rubification are evidence of a hot and humid climate.Mobilization and stabilization of the aeolian dune is an important characteristic of the coastal evolution in South China since the late Pleistocene.
基金supported by National Natural Science Foundation of China(Grant Nos.41301012,42077407 and 41771020),Natural Science Foundation of Fujian Province,China(Grant No.2020J01185),and the Innovation Research Team Fund of Fujian Normal University(Grant No.IRTL1705).
文摘The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi Mountain of South China,represents the first discovered and scientifically excavated Middle Palaeolithic site in the Fujian Province.This site is of considerable significance for studying the diffusion and cultural connotation of early Homo sapiens in southern China.In this study,we present optically stimulated luminescence(OSL)ages obtained from medium-grained quartz collected at the LPS.The single-aliquot regenerative-dose measurements of red soil deposits collected at the same site yielded internally and stratigraphically consistent ages and similar errors,indicating a potential ability of the technique,and also reflecting the influence of various sedimentary facies on the test results.Our results indicate that the 38–63µm quartz grains were generally partially-bleached and had large values of over-dispersion in the palaeo-reticulated laterites of west Fujian.Some samples yielded unsatisfactory results,suggesting that the degree of bleaching of diluvial and alluvial deposits should be properly assessed before dating.We did not detect any enrichment/depletion of U,Th and radioactive disequilibrium.The effect of chemical weathering on the dose rate estimation was negligible.Therefore,we used a central age model and the maximum age model to calculate the age of two samples,respectively,and the minimum age model to calculate the ages of the rest of the samples.The OSL ages of the samples ranged from 27.09±2.30 ka to 54.65±7.39 ka for the 38–63µm quartz size fraction,and roughly corresponded to the Marine Isotope Stage 3.In addition,three ages out of five are based on the calculation of minimum ages in this research,which needs to be further verified by other dating methods.
基金supported by the National Natural Science Foundation of China(Grant Nos.41301012,41771020)the Natural Science Foundation of Fujian Province,China(Grant No.2020J01185)。
文摘The Aeolian foredunes in the southern coast of China are records of paleoenvironmental changes for marine monsoon region. Intensive studies have been conducted to decipher their formation and paleoenvironmental implications in which chronology played a key role. However, robust dating results are still limited due to the scarcity of organic materials for radiocarbon and the limited application of quartz optically stimulated luminescence(OSL). Here, we collected 11 OSL samples and 140 grainsize samples from the Changle section with a thickness of 7 m from a coastal foredune in Fujian Province. The dating results indicated that the section spanned a time period from 0.32±0.04 ka(depth of 700 cm) to 0.18±0.02 ka(depth of 80 cm), after removal of age outliers. According to the OSL ages and sedimentary structural characteristics, the section could be divided into two stages, i.e. the stable accumulation period with an age range of 0.32-0.18 ka from the depth of 700 cm to 80 cm, and the activation period above the depth of 60 cm, at which the dune erosion was retained. The foredune development due to increased transport of dune sediment at the top part of the section was the result of recent human activities.Inside the foredunes, normal cross-bedding was generated by seasonal changes in wind direction.Seasonal changes in the wind direction were the primary cause for various sedimentary bedding within the dunes.
