Sedimentary characteristics of paleo-aeolian dune sands of Salawusu Formation in the Salawusu River Valley     

OU Xianjiao  LI Baosheng  JIN Heling  DONG Guangrong  David Dian ZHANG  WU Zheng  WEN Xiaohao  ZENG Lanhua  OUYANG Chuntao  YANG Yi  LIU Yufei 《地理学报》2008,18(2):211-224

The Salawusu Formation of Milanggouwan section in Salawusu River Valley in-cludes 7 layers of paleo-mobile dune sands, and 4 layers of paleo-fixed and semi-fixed dune sands. Their structures have been observed and their grain size, surface textural features and several main chemical elements have been analyzed. The results showed that: 1) Some of the aeolian structural characteristics of these dune sands are similar to that of the recent dune sands. 2) They are also similar to the recent dune sands in grain size components, and parameters of Mz, σ, Sk and Kg, as well as in several main chemical components. 3) The scattergrams of Mz-σ and SiO2–Al2O3+TOFE and the probability curves of grain size showed that these paleo-dune sands are different from paleosols and fluvio-lacustrine facies, but are consistency with recent dune sands. 4) Quartz sands have well roundness and surface textural features such as dish-shaped pits, crescent-shaped pits, pockmarked pits, upturned cleavage plates, siliceous precipitates and siliceous crevasses, indicating that they had been carried for a long time by the wind. As the 11 layers of paleo-dune sands possess the aeolian characteristics in structure, grain size, surface textural features and chemical elements, the origin of their formation should be attributed to eolation.  相似文献   

青藏高原东北部共和盆地风成沉积地球化学特征及其揭示的气候变化   总被引：4，自引：0，他引：4  

刘冰  靳鹤龄  孙忠  苏志珠  张彩霞 《地球科学进展》2012,27(7):788-799

通过对共和盆地东部风成沉积的地球化学分析,并结合14C和OSL年代,重建了区域末次盛冰期以来气候变化过程。21 ka BP之前气候寒冷偏湿,21～15.82 ka BP为末次盛冰期(LastGlacial Maximum,LGM),气候极为寒冷干燥;15.82～9.5 ka BP气候转暖且偏干,其中14.5～13.6ka BP和11.9～9.5 ka BP气候明显冷干,分别为老仙女木时期(Oldest Dryas,OD)和新仙女木时期(Younger Dryas,YD),而15.82～14.5 ka BP和13.6～11.9 ka BP(BФlling-AllerФd暖期,B/A)相对温暖;9.5～7.2 ka BP暖湿程度明显提高,7.2～5.1 ka BP气候波动频繁,相对冷干和相对暖湿多次更替。5.1～2.7 ka BP暖湿程度基本稳定,之后气候趋于寒冷但湿度明显较大。这些气候变化过程与青藏高原大量的古气候信息记录具有良好的一致性,表明共和盆地气候变化与青藏高原气候变化的高度一致性。  相似文献   

西北半干旱雨养农业区薯麦轮作FACE平台简介     

赵鸿  张强  李耀辉  倾继祖  王润元  杨启国  王鹤龄  仝乘风  魏强 《干旱气象》2011,29(1):100-105

在黄土高原半干旱雨养农业区薯麦轮作田地建立气象部门首家FACE系统(Free Air CO<,2>En-richment),即CO<,2>浓度的控制和监测系统平台,由中国气象局兰州干旱气象研究所建在定西半干旱生态环境与试验基地.该平台由CO<,2>气体供应装置、控制系统、释放系统3大部分组成,它是利用计算机网络系统对平...  相似文献   

粒度特征揭示的中全新世以来毛乌素沙地演化过程   总被引：1，自引：1，他引：0  

刘振宇  靳鹤龄  刘冰  薛文萍 《中国沙漠》2019,39(1):88-96

通过对毛乌素沙地现代固定沙丘、半固定沙丘、半流动沙丘和流动沙丘的粒度特征分析,发现研究区沙地变化敏感粒度是>245 μm的沉积物粒度组分,尝试性地将其用于地质时期沙地演化研究。结合区域典型风成砂-古土壤剖面的沉积相特征,探讨了中晚全新世以来毛乌素沙地的时间演化过程及其特征。结果表明：中全新世以来毛乌素沙地存在多次活化扩张和固定萎缩事件,除7.5 ka BP前为流动沙地占优势以外,其余阶段多在半流动沙地、半固定沙地和固定沙地之间频繁转换,即使在全新世适宜期古土壤大规模发育期间仍存在局地短时间的沙地活化事件。  相似文献   

莒县三措并举切实搞好耕地保护工作          下载免费PDF全文

卢守润  方和玲  王祥福 《山东国土资源》2009,25(2)

损毁山体严重影响城市和交通沿线景观,景观影响度可作为一个综合指标来反映损毁山体对城市景观的影响程度。应用专家评分综合评判法结合地理信息系统确定景观影响度分级标准,对损毁山体进行景观影响程度的评价与分析,得出景观影响度分类结果,为损毁山体的治理规划和有序整治提供科学依据。  相似文献   

THE　CAUSES　AND　DEVELOPMENTAL　TREND　OF　DESERTIFICATION　IN　THE　MIDDLE　REACHES　OF　THE　YARLUNG　ZANGBO　RIVER　AND　ITS　TWO　TRIBUTARIES　IN　XIZANG   总被引：3，自引：0，他引：3  

董光荣  董玉祥  李森  金炯  靳鹤龄  刘玉璋 《中国地理科学(英文版)》1995,5(4):355-364

ＴＨＥＣＡＵＳＥＳＡＮＤＤＥＶＥＬＯＰＭＥＮＴＡＬＴＲＥＮＤＯＦＤＥＳＥＲＴＩＦＩＣＡＴＩＯＮＩＮＴＨＥＭＩＤＤＬＥＲＥＡＣＨＥＳＯＦＴＨＥＹＡＲＬＵＮＧＺＡＮＧＢＯＲＩＶＥＲＡＮＤＩＴＳＴＷＯＴＲＩＢＵＴＡＲＩＥＳＩＮＸＩＺＡＮＧＤｏｎｇＧｕａｎｇ...  相似文献   

黄土地层中奇异微颗粒的发现与初步研究   总被引：10，自引：1，他引：10  

徐和聆  安芷生 《海洋地质与第四纪地质》1993,13(3):57-66

通过蓝田段家坡黄土和红粘土剖面与第四纪3次巨大撞击事件年代相应的地层内奇异微颗粒的研究,将其划分为5种不同的形态类型,并主要据化学成分,将5类奇异微颗粒归纳为撞击、火山和生物等3种成因类型。文中还提出综合成因模式来解释不同奇异微颗粒赋存于同一撞击事件时段的地层及它们所显示的因果联系。  相似文献   

西北干旱区棉花对气候变化响应的评价指标体系     

赵鸿  王润元  王鹤龄  杨启国  陈雷 《干旱气象》2008,26(4)

近年来,在全球变暖的大背景下,西北也经历着同样的变暖趋势,尤其在西北干旱区新疆、甘肃河西走廊等地的棉花种植区,气候变暖对棉花生长发育的影响研究日益增多,但如何正确、合理地评价棉花对气候变暖的响应,已成为目前十分突出的科学和实际问题。在评价的过程中,评价指标的选择和确定是重中之重。鉴于此,本文筛选了几类重要的评价指标,主要有棉花生长发育、产量品质、种植结构、地理分布、农业气象灾害、农业病虫害气象指标等,这些指标的选择为科学评价棉花对气候变化的响应奠定了一定的基础。  相似文献   

A Multi-cycle Climatic Fluctuation Record of the Last Interglacial Period:Typical Stratigraphic Section in the Salawusu River Valley on the Ordos Plateau,China   总被引：5，自引：0，他引：5  

LIBaosheng DavidDianZHANG WENXiaohao DONGYuxiang ZHUYizhi JINHeling 《《地质学报》英文版》2005,79(3):398-404

The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and paleosols. Based on comprehensive analyses on the distribution of magnetic susceptibility and CaCO3 and paleo-ecology indicated by fossils in the region, it is considered that the sedimentation cycles resulted from dry-cold and warm-humid climate fluctuations. Magnetic susceptibility values and CaCO3 contents in stratigraphic sectors Ⅰ, Ⅲ, Ⅴ and Ⅱ, Ⅳ basically respectively present peaks and low vales, and the former three can in time correlate with MIS5a, MIS5c and MIS5e successively and the latter two with MIS5b and MIS5d. In addition, some horizons of eolian dune sands and the low vales of their magnetic susceptibility and CaCO3 are also correlated with 6 periods of cooling events indicated by the higher content of foraminifer Neogloboquadrina pachyderma (S.) documented in the V29-191 drill in the North Atlantic and the cold events recorded by δ^18O in the ice cores in GRIP, especially with 9 periods of dust events in Chinese Loess Plateau.  相似文献   

Aeolian Facies Belts in the Taklimakan Desert1     

Li Baosheng  Dong Guangrong  Zhang Jiasheng  Li Sen  Jin Heling  Chen Huizhong  Wen Xiangle  Wang Yao  Zhu Yizhi 《《地质学报》英文版》1995,8(3):317-328

At least at the beginning of the last glacial epoch, the facies belts of dune sand, sandy loam and loess formed by winds had existed in the Taklimakan desert and areas south of it. There were no appreciable changes in the NE and NW wind systems and their wind forces that deposited dune sand, sandy loam and loess in the global cold stage since the last glacial epoch; accordingly no marked shifts of the boundaries of these aeolian facies belts took place. In the global warm stage since then, the climate in the Taklimakan desert and areas south of it became warm and dry, resulting in ablation of substantial volumes of ice and snow in their surrounding mountains and thus forming alluvial and diluvial deposits in the region. The alluvial-diluvial actions, however, failed to change the general framework of aeolian facies belts.  相似文献