East Asian Winter Monsoon record from the environmental sensitive grain size component of QF Old Red Sand, Haitan Island, China

The ＂Old Red Sand＂ is widely distributed along the coast of Fujian Province, China. Most studies have been carried out from as- pects of the origin, age and laterization of the ＂Old Red Sand＂, but this paper focused on reconstructing the history of the Asian Winter Monsoon change. On the basis of granulometric analysis of high-resohition samples, we have obtained environmental sen- sitive grain size component （ESGSC） from the Qingfeng （QF） profile by using the grain size-standard deviation method, which proves that the selected ESGSC is an important climate proxy. The mean grain size of this ESGSC could be used to reconstruct the East Asian Winter Monsoon （EAWM） intensity. As such, the history of the EAWM change since 44.0 ka reconstructed here reveals three main phases based on chronology dates of previous researches： （1） 44.0-25.5 ka B.P., the EAWM is relatively weak but increases gradually with fluctuations; （2） 25.5-15.5 ka B.P., relatively strong with high frequency fluctuations; （3） 15.5-7.1 ka B.P., with a weaker winter monsoon, but during 11-10 ka B.P. is remarkably enhanced. The EAWM recorded by mean grain size of the two neighboring sections have a better repeatability, so the millennial scales oscillation should be a reliable signal of the EAWM intensity. The climate recorded by ESGSC of the QF ＂Old Red Sand＂ compared to 6-80 of Huhi Cave stalagmites and Greenland GISP2 ice cores shows a good consistency, especially in detail, the YD event and four Heinrich events are all recorded, but the signal of D-O cycles was relatively weak.

Current study and prospect of the Old Red Sand along the southeast coast of China

The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.

Analysis of the Sedimentary Characteristics and Origin of the “Old Red Sands ”in the Coastal Areas of Southeast Fujian

The "Old Red Sands" are widely distributed and typically developed over the coastal areas of Southeast Fujian, but there are different views on their origin. Based on the overall field investigations and a series of lab studies, the paper suggests that the "Old Red Sands" are mainly formed by the beach wind-drift sands and ,locally, by slope wash and alluviation.

The age of the "old red sand" on the coasts of south Fujian and west Guangdong, China

The sedimentary strata and deposition ages of the 'old red sand' distributed along the coasts of south Fujian and west Guangdong are determined by lithostratigraphy, magnetic stratigraphy and earth chemistry combined with TL, ESR and 14C-dating techniques. The research shows that the 'old red sand' was aeolian sediments deposited from 55 400 to 9 000 aBP, the last glacial period in the middle and later age of Late Pleistocene. Most of them deposited in two periods of 56-42 ka and 30-10 ka. The 'old red sand' deposited in the period of 30-10 ka, the later Wurm glacier substage (Q33), developed on the largest scale with the widest distribution.

Formation of "old red sands" and paleogeographic environment on South China coasts

The formation and development environment of the "old red sands" on South China coasts is discussed according to the investigation in the field and laboratory works. The authors believed that the "old red sands" are the aeolian sediments deposits in the last glacial period of late Pleistocene when the sea level was lower than the present, and the laterization took place under the hot and wet climate during the later interglacial and postglacial periods when the sea level was relatively high.

Luminescence chronology of “Old Red Sand” in Jinjiang and its implications for optical dating of sediments in South China

A weathered deposit in South China is widespread on the coastal areas of Fujian and Guangdong provinces,China.This deposit consists of slightly cemented,medium-to fine-grained sands,and is characterized by its colors of red,brown red,light reddish brown or dark yellowish orange,and is usually called "Old Red Sand".The uncertainty in its formation age has been a major obstacle to the study of this type of deposit.In this paper,optically stimulated luminescence(OSL) techniques were used to date the "Old Red Sand" sediments from Jinjiang,Fujian Province,China.The effect of the geochemical behavior of uranium and thorium in sediment during chemical weathering on estimation of annual dose was investigated.The results show that the change in annual dose due to weathering poses a major problem for the optical dating of such weathered sediments.The optical dating of these weathered deposits will produce erroneous ages if average annual dose during burial cannot be correctly estimated.For the profiles studied,the OSL dates obtained on samples from the upper part do not represent the burial age of the samples.It is highly likely that they are underestimated due mainly to the accumulated radioactive elements as a result of chemical weathering.It is concluded that changes in annual dose due to chemical weathering must be considered when dating similar sediments in South China.With a detailed analysis of the OSL dating results,the chronology of the marine terraces in this area was suggested.The lowest terrace was formed at ～3.5 ka and the second terrace was dated to ～74 ka.The age of the highest terrace may not be established accurately,but is inferred to be older than the apparent OSL date of～77 ka and so is the Paleolithic artifacts from it.

福建平潭青峰老红砂中季风组分以及形成期研究

先前研究认为老红砂是末次冰期沿海风沙沉积,近期发现老红砂形成于末次间冰期。在福建平潭青峰典型老红砂分布区采集114个老红砂样品,130冬季风沙样品,60个夏季风沙样品做粒度测量和光释光测年。粒度测量显示冬季风沙粒度频率峰值出现在400μm、夏季风沙280μm,老红砂粒度频率峰值出现在300μm与冬季风沙不同。夏季风沙和冬季风沙以7∶3混合可拟合老红砂粒度分布,表明青峰老红砂沉积期夏季风历时或强度远大于冬季风,对应于气候暖期,而不是末次冰期。老红砂剖面4个自然层光释光测年自下而上为122.5±6.7 ka B.P.、97.7±6.1 ka B.P.、83.1±4.2 ka B.P.、61.9±3.4 ka B.P.,对应末次间冰期,青峰老红砂是暖期气候的风沙响应。

华南老红砂沉积年代学及其环境意义:以福建青峰老红砂为例

对福建海坛岛青峰老红砂进行了系统的光释光测年研究,结合已发表的相关测年数据,在统一的时间标尺上探讨了老红砂发育过程及其与海平面变化和东亚季风变化之间的关系。结果表明:1 QFS剖面沉积年龄为110~33 ka,起始发育年龄延伸到了末次间冰期。主要涵盖了MIS5c^MIS3阶段,其中存在4个快速堆积期。结合已发表的年代学数据进行综合分析,认为前人得出的老红砂发育在末次冰期以来的结论需要得到修正。2华南老红砂发育过程与区域海平面变化密切相关。在末次间冰期和末次冰期均有发育,高海面(>-50 m)或较高海面(-50^-70 m)时期是老红砂普遍发育期。区域地壳运动叠加海平面变化造成闽南和闽东北老红砂的沉积差异:海退过程中的较高海面时期北部先发生快速堆积;海侵过程中的较高海面时期南部先发生快速堆积。LGM(海平面<-70 m)期,老红砂不发育。3老红砂在冰期-间冰期尺度上的沉积速率体现了源区气候和海平面变化对老红砂物源输送的双重制约。

中国东南沿海老红砂研究综述

老红砂是中国东南沿海独具特色的第四纪沉积物。本文回顾了老红砂的研究历史，综述了所取得的关于老红砂的成因、年代和红化作用等主要研究成果及其存在问题，并提出了今后进一步工作的意见。

闽东南沿海老红砂的分布与沉积地貌特征

本文通过野外调查，阐明了老红砂的分布与地貌形态特征，并根据其沉积构造特征等提出了老红砂的风成或风—被积成因及其发育多期性的观点。最后还对进一步研究提出若干建议。

闽东南沿海老红砂沉积地层与形成时代

采用岩石地层学、磁性地层学和地球化学等方法，结合ＴＬ、ＥＳＲ和１４Ｃ等测年，对广泛分布于闽东南沿海的老红砂沉积地层及其形成时代进行了划分。结果表明，该区老红砂沉积地层可综合划分为５个地层段，其中老红砂层可分出３ 个地层段，分属６０～４０ ｋａ Ｂ．Ｐ．、３０～２５ ｋａ Ｂ．Ｐ．和２０～１０ ｋａ Ｂ．Ｐ．所形成；两个古土层，反映大约在４０～３０ ｋａ Ｂ．Ｐ．和２５～２０ ｋａ Ｂ．Ｐ．老红砂的发育有过两次较长时间的沉积间断或减弱。

闽东南沿海老红砂与晚第四纪环境演变

闽东南沿海老红砂发育较典型，分布较广，但迄今对其形成多有不同认识。论文在进行全面野外调查和一系列的室内分析的基础上，认为闽东南沿海的老红砂主要是由风吹扬海滩砂形成的，局部地方还有坡积、冲积等成因，并可划分成６～４．５万ａＢＰ和３～１万ａＢＰ两个相对较集中的形成期。末次冰期寒冷干燥的气候为老红砂的形成提供了有利条件，末次冰期中的亚间冰期和冰后期温暖湿润的古气候环境则有利于其后的固定（红化固结、生草、发育古土壤等）。

闽东南沿海老红砂沉积特征与成因分析

闽东南沿海老红砂分布广泛,发育较典型,但迄今对其成因多有不同认识.本文在进行全面野外调查和一系列的室内分析的基础上,认为本研究区的老红砂主要是由风吹扬海滩砂形成的,局部地方有坡积和冲积等成因.

闽粤沿海老红砂多期沉积地层的发现及其意义

对广泛分布于闽粤沿海的老红砂进行了全面的野外调查 ,调查发现在福建的平潭青峰、晋江科任和广东的惠来靖海资深园、徐闻锦和东门下等地的老红砂沉积地层 ,存在多期沉积。热释光 (TL)、电子自旋共振 (ESR)测年表明 ,它们是晚更新世中、晚期末次冰期 (玉木冰期 )的沉积 ,并可分出 6 8～ 42ka和 30～ 10ka两个相对较集中的沉积期。在这两期中 ,又以 30～ 10ka左右的晚玉木冰期 (Q3 3 )的老红砂发育规模最大、分布最广 ,这显然与晚玉木冰期 (盛冰期 )时的气候更干冷、冬季风的风力更强劲 ,风沙活动更强烈有密切关系。

福建晋江科任剖面老红砂主元素反映的晚更新世以来气候变化

以福建晋江科任剖面老红砂为研究对象,对剖面主元素地球化学特征及其指示的古环境意义进行初步研究。结果表明:(1)科任剖面以湿润型元素SiO2、Al2O3、Fe2O3为主,含量范围依次为68.88%～93.77%、9.03%～19.1%和2.14%～5.32%;干旱型元素CaO、Na2O、MgO和K2O的含量均小于0.5%,K2O的含量略高于2%,表现为较强烈淋溶;主元素分布特征、风化特征值、CIA值等均表明,科任剖面老红砂总体上属于轻度富铝化。(2)对特征元素组合、元素比值和磁化率等古气候古环境代用指标进行分析,认为晚更新世中期以来,科任剖面记录了较干冷—暖湿—干冷—暖湿4个阶段的气候变化:55.9～43.9kaBP和27.0～10.8kaBP两个时期,气候干冷,冬季风强烈,为风沙堆积的两个主要阶段;43.9～27.0ka和10.8ka以来,气候温暖湿润,为风沙经历强烈风化和红化作用阶段。

闽粤沿海老红砂的热释光测年

采用再生热释光法对来自福建和广东沿海地区的 39个老红砂样品进行了测年 ,其年龄约在 0 9～ 6 8万年之间 ,表明闽粤沿海的老红砂是晚更新世中、晚期形成的风成沉积。

粤东及琼东北第四纪老红砂风成的若干证据

粤东及琼东北第四纪老红砂分布于全新世和现代海岸风沙强烈作用带，其野外产状、沉积构造与海滩砂不同，粒度、石英砂磨圆度、石英砂表面微结构统计、孢粉和硅藻等分析证明这些老红砂与海岸沙丘砂有着成因上的联系，热释光年代为距今1．62—5．19万a，故它们是毗邻海滩的海岸风成砂，形成于未次冰期的低海平面期，其形成和分布与盛行风和向岸风的共同作用有关。

晚更新世以来闽东南老红砂沉积粒度特征与古气候变化

对闽东南深沪湾老红砂风沙沉积进行粒度测试,提取对环境变化敏感的粒级组分,结合年代学数据,初步划分了研究区晚更新世中晚期以来的气候变化阶段和气候驱动因素。研究发现,研究区经历了较冷干-暖湿-冷干-暖湿4个气候变化过程。气候变化主要受控于太阳辐射,表现出明显的23 ka长岁差周期、14.2 ka、11.8 ka半岁差周期,叠加约0.25 ka的双世纪周期,陆地-海洋-大气系统的内部因素对表现出来的百年周期可能产生放大或缩小影响。70.8—46.4 ka BP和21.3—11.6 ka BP两个阶段老红砂沉积速率较大,是老红砂风沙堆积的两个主要时期,两个阶段沉积速率分别达到30 mm/(100 a)、650 mm/(100 a)。

中国、日本晚更新世海岸古沙丘之比较

本文对中国、日本晚更新世古沙丘(中国称为'老红砂')的分布、高度、规(?)粒度、化学性质、沉积结构、地层层序及其成因等进行了全面对比分析。作者认为,(?)丘的沉积层序表明,最终冰期至少有四次环境变化的旋回;古沙丘的颜色特征则表明其红土化作用与亚间冰期的温暖古气候有关。

闽东南沿海老红砂的地球化学特征

闽东南沿海老红砂的地球化学分析表明 ,B、Ga、Sr、Ba、K、Cr、Ni和 V等微量元素含量及 B/ Ga和 Sr/ Ba比值指示老红砂应为陆相沉积 ,其磷酸钙组分和古盐度亦指示为陆相。老红砂的化学全量组合特征与花岗岩风化壳相似 ,但 Si O2 含量较花岗岩风化壳大 ,而 Al2 O3的含量明显少于花岗岩风化壳。从老红砂垂直剖面变化看 ,其硅铝铁率一般从上往下增加 ,分解系数 ( Fe2 O3/ Mg O)一般从上往下减少。