柴达木盆地盐湖沉积磁性地层年代学研究进展

 柴达木盆地因其巨厚的新生代盐湖沉积成为研究青藏高原隆升、古湖泊演化、气候环境演变以及盐类资源钾盐勘探开发的热点地区之一。而磁性地层年代学是这种长尺度湖相沉积研究中必不可少的定年方法。总结了早期柴达木盆地各个沉积中心的磁性地层结果,详细描述了近年来已发表的最新3个千米钻孔的磁性地层年代成果,包括柴达木盆地西部大浪滩沉积中心的梁ZK02孔和梁ZK05孔、察汗斯图拉沉积中心的SG-1孔。根据新的磁性地层年代结果,重新厘定了柴达木盆地西部沉积中心的第四纪底界深度,并为探讨柴达木盆地第四纪气候变化、青藏高原阶段性隆升和新型的砂砾层卤水资源提供了精确的年代制约。     

柴达木盆地东部地区中生界不整合与油气成藏的关系

地层不整合对油气成藏具有重要作用.柴达木盆地经历了多次构造运动的改造,形成了多个不整合.在测井曲线分析的基础上,结合岩心观察、不整合成因机制及地震反射特征分析,对该区不整合与油气成藏的关系进行了研究.结果表明,柴达木盆地东部地区中生界不整合可划分为削截不整合、超覆不整合、断褶不整合和平行不整合4种类型.受不整合的控制,油气沿不整合面运移,风化剥蚀程度的不均一性使不整合具有典型的层状结构,将不整合面上、下划分为底砾岩、风化粘土层和半风化淋滤带.在纵向上,不整合的分层结构可构成油气运移的双重通道,为油气聚集提供良好的储集空间和圈闭条件.不同的不整合剖面类型可以形成不同的油气成藏模式.     

塔里木盆地志留-泥盆系层序界面特征及成因类型

在层序地层学研究中关键是有关界面的识别,尤其是层序底界面的识别.以新疆塔里木盆地志留系-泥盆系为例,在大量野外剖面详细观测的基础上,识别出了层序底界面的物质表现形式有7种类型,它们分别是:古风化壳,渣状层,斜坡重力流冲刷侵蚀面,超覆面,最大海泛面,岩性、岩相转换面,侵蚀冲刷面.在详细讨论了各类型界面特征的基础上,将上述界面可归结为4种成因类型,分别是:造山侵蚀层序不整合界面,隆升侵蚀层序不整合界面,海侵上超层序不整合界面,陆上暴露层序不整合界面.这一研究成果对于正确识别和划分层序具有重要的意义.     

鄂尔多斯盆地三叠系与侏罗系不整合面测井识别方法讨论

利用区域地质背景和测井资料,用测井方法对鄂尔多斯盆地三叠系与侏罗系之间不整合面进行识别,为准确划分鄂尔多斯盆地中生代地层提供依据。研究后认为,不整合面上下地层的接触关系分为5种类型,不同类型的特征及识别方法受延长组顶部地层的剥蚀程度和前侏罗纪古地貌特征共同控制。测井方法识别不整合面最主要的依据有两个:一是河道充填砂岩形成的箱型测井曲线的底界,主要发育在甘陕古河谷;二是由于不整合面下发育黏土风化壳而使不整合面上具有电阻率值最小的特征,主要发育在古地貌的斜坡带。此外,不整合面的识别还需参考不整合面上下地层的岩性、厚度、标志层特征,同时结合邻井对比和等厚原则,才可有效准确地识别不整合面,并对不整合面上下地层的接触关系进行准确的划分。     

柴达木盆地东部地区中生界不整合与油气成藏的关系

地层不整合对油气成藏具有重要作用。柴达木盆地经历了多次构造运动的改造，形成了多个不整合。在测井曲线分析的基础上，结合岩心观察、不整合成因机制及地震反射特征分析，对该区不整合与油气成藏的关系进行了研究。结果表明，柴达木盆地东部地区中生界不整合可划分为削截不整合、超覆不整合、断褶不整合和平行不整合4种类型。受不整合的控制，油气沿不整合面运移，风化剥蚀程度的不均一性使不整合具有典型的层状结构，将不整合面上、下划分为底砾岩、风化粘土层和半风化淋滤带。在纵向上，不整合的分层结构可构成油气运移的双重通道，为油气聚集提供良好的储集空间和圈闭条件。不同的不整合剖面类型可以形成不同的油气成藏模式。     

川西前陆盆地侏罗系层序地层

川西前陆盆地休罗系为陆相碎屑岩地层。其中可以识别的层序界面有不整合面、最大湖泛面。最大进积面即为不整合面,而最大退积面则对应于最大湖泛面。根据川西前陆盆地的构造、沉积作用特点,选择进积体系域底界为层序界面,将川西前陆盆地侏罗系划分为8个沉积层序,可以在全盆地进行时比。     

谢桥煤矿煤系上覆第四纪底砾层隔水性评价

第四纪底砾层直接覆盖在谢桥煤矿煤系地层之上，其隔水性能影响到防水煤柱的合理留设。为论证底砾层的隔水性，分析研究其赋存特征、岩性组合，并对其进行抽提水、简易水文和水动态观测试验。结果表明：第四纪底砾层不含水，渗透性极弱而且具有良好的隔水性，是阻碍新生界中部含水层危害矿井安全开采的良好隔水层，为合理留设煤柱、确定回采上限提供可靠的依据。     

准噶尔盆地侏罗纪高精度层序地层格架研究

本文以准噶尔盆地侏罗纪高精度层序地层研究为基础对盆地的层序构成及其格架特征进行了精细研究,结果表明:准噶尔盆地侏罗系构造层序为源来自盆地南侧幕式强挤压逆冲,东北和西北及西侧被动响应,形成边缘坳陷中央隆起的“2梁3洼”的复合类前陆盆地并接受充填沉积,其顶界为白垩系吐谷鲁群底界面(SBK1tg),底界为下侏罗统八道湾组底界(SBJ1b3)的区域不整合面。包括2个层序组:早中侏罗层序组(SJ1-J2层序组)、中晚侏罗层序组(SJ2-J3层序组)。     

柴达木盆地成盐期与青藏高原第四纪冰期及构造运动阶段的相关性

 柴达木盆地沉积有巨厚的晚新生代沉积物和丰富的矿产资源,是研究晚新生代以来气候与环境变化、构造运动与盆地演化、成盐成矿规律的理想地区。通过对柴达木盆地钻孔和剖面的含盐地层测年数据进行总结,并与青藏高原第四纪冰川活动和构造运动进行对比,认为柴达木盆地成盐期与青藏高原第四纪冰期及构造运动阶段具有一定的对应关系。柴达木盆地西部盐湖和干盐湖中通常发育有倒数第二次冰期及末次冰期的石盐层,某些盐湖中还有希夏邦玛冰期、望昆冰期、中梁赣冰期的石盐层;迄今为止在柴达木盆地东部的察尔汗盐湖区中仅发现末次冰期以来的石盐层。冰期环境下的干冷气候及冰川扩张,造成盐湖补给水源的减少,有利于盐类物质的沉积。     

集合卡尔曼滤波法在土壤湿度遥感数据融合的研究

土壤湿度是地表和大气在能量交换、物质交换、水分交换过程中的重要参数,准确、快速地获取土壤湿度数据对人类生产生活、植物生长、大气变化等方面都起到了至关重要的作用.本文以AMSR-E和ASCAT两种遥感数据出发,使用集合卡尔曼滤波法融合方法对土壤湿度遥感数据进行融合.我国柴达木盆地,平均海拔在3000m以上,环境恶劣,土壤湿度地面检测站点稀少,本文研究结果有助于深入了解柴达木盆地土壤湿度的获取,对柴达木盆地的生态保护、水资源评价、环境变化等方面具有重要科学意义,也可以为该地区农业生产提供了合理依据.     

Constraints on the late Mesozoic regional angular unconformity in West Liaoning-North Hebei by LA-ICP-MS dating

The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems, and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North Hebei. Moreover, the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 135 Myr in the past. Based on the detailed study and systematic sampling in Yixian-Beipiao, Lingyuan, Chengde and Luanping areas in the field, the authors obtained the following isotopic ages by means of LA-ICP-MS dating: In the Lingyuan area, the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact; the age range of the Zhangjiakou Formation volcanic rock is from 133 to 130 Myr (seven samples), and that of the Yixian Formation volcanic rock is from 126 to 121 Myr (eleven samples). In the Luotuoshan of Chengde, the Tuchengzi Formation and the Zhangjiakou Formation are in angular unconformable contact; the age at the lower Zhangiiakou Formation is about 124 Myr (one sample), which reflects that the age range of the lower Zhangjiakou Formation is from 129 to 124 Myr combined with the previous study. In the Luanping basin, there is the largest sediment gap in upper Mesozoic, whose lower boundary age is confined in 131 to 130 Myr. In the Yixian-Beipiao area, the second Member of the Yixian Formation, making up more than 3/4 thickness of the Yixian Formation, was formed in 126 to 119 Myr, and the age of the Yixian Formation at the bottom is about 132 Myr. Moreover, the upper boundary age of the Tuchengzi Formation is about 136 Myr in the West Liaoning-North Hebei region. Based on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region, it reflects that there was a widespread tectonic event in the period of 136 to 126 Myr (mainly in 130-126 Myr) in the West Liaoning-North Hebei, and it formed the late Mesozoic regional angular unconformity. Moreover, the lower boundary ages of the late Mesozoic regional angular unconformity in different areas are different, and the tectonics and the creature assemblage are different in the strata at the top and bottom of the regional angular unconformity. It implies that the late Mesozoic regional angular unconformity is a regional interface of tectonic transformation in Mesozoic Era in the West Liaoning-North Hebei.     

Constraint on the late Mesozoic regional angular unconformity in West Liaoning--North Hebei by LA-ICP-MS dating

The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems, and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North Hebei. Moreover, the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 135 Myr in the past. Based on the detailed study and systematic sampling in Yixian-Beipiao, Lingy- uan, Chengde and Luanping areas in the field, the authors obtained the following isotopic ages by means of LA-ICP-MS dating： In the Lingyuan area, the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact; the age range of the Zhangjiakou Formation volcanic rock is from 133 to 130 Myr （seven samples）, and that of the Yixian Formation volcanic rock is from 126 to 121 Myr （eleven samples）. In the Luotuoshan of Chengde, the Tuchengzi Formation and the Zhangjiakou Formation are in angu- lar unconformable contact; the age at the lower Zhangjiakou Formation is about 124 Myr （one sample）, which reflects that the age range of the lower Zhangjiakou Formation is from 129 to 124 Myr combined with the previous study. In the Luanping basin, there is the larg- est sediment gap in upper Mesozoic, whose lower boundary age is confined in 131 to 130 Myr. In the Yixian-Beipiao area, the second Member of the Yixian Formation, making up more than 3/4 thickness of the Yixian Formation, was formed in 126 to 119 Myr, and the age of the Yixian Formation at the bottom is about 132 Myr. Moreover, the upper boundary age of the Tuchengzi Formation is about 136 Myr in the West Liaoning-North Hebei region. Based on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region, it reflects that there was a widespread tectonic event in the period of 136 to 126 Myr （mainly in 130-126 Myr） in the West Liaoning-North Hebei, and it formed th     

从哺乳动物群的变化分析蓝田地区第四纪古气候的发展

本文从蓝田地区第四纪古哺乳动物群的结构变化入手,分析了该区古气候的变化趋势。进而从动物地理、动物生态等方面对其结论进行了验证,两者基本吻合。     

渝鄂湘黔毗邻地区古冰川研究

在地质历史中,地球曾发生过震旦纪冰川、石炭-二叠纪冰川和第四纪冰川3次冰川活动。为研究和预测当今气候,按照岩石学原理和李四光教授创立的确定古冰川的3个标准,研究了渝鄂湘黔毗邻地区的古冰川事件,结论是该区只发生过震旦纪冰川;第四纪时不存在古冰川遗迹,没有发生过冰川活动;为温暖湿润气候。     

中国西北地区黄土及第四纪地层研究的新进展

利用沉积学、古地磁学、同位素年代学、微生物学及构造地貌学等学科，结合区域地层对比，对中国西北地区黄土及第四纪地层和晚新生代构造变形特征进行了较为广泛、系统和深入的多学科综合分析研究。认为在更新世地质事件及发生年龄、典型风成黄土及形成下限、新疆西域砾岩时代归属、西北地区第四纪下限、黄土地层中的微生物及地质意义和新构造演化性质等第四纪地质的前沿领域取得了重要进展。     

东海陆架与冲绳海槽晚第四纪沉积硅藻的对比研究

通过对东海陆架DG9617孔以及冲绳海槽A孔和B孔岩芯沉积硅藻进行高分辨率的采样分析,总共鉴定出166种和变种,其中有近14个主要硅藻种在3个钻孔中都连续分布,且有较高的含量,而其余种类含量较低或分布不连续或仅零星检出.根据3个钻孔岩芯中产出硅藻属种组成、含量变化及热带远洋种丰度等特征建立起各自的硅藻组合带.通过对比分析,表明硅藻植物群在东海陆架及冲绳海槽不同沉积环境条件下均记录了自晚第四纪以来古海洋、古气候的变化.     

New focuses of polar ice-core study: NEEM and Dome A

Ice core records from polar regions are of great value to study long-term climate and environmental change. Greenland ice-core records are celebrated for their high resolution and have provided very important knowledge for understanding the late Quaternary palaeoclimate, especially in reference to millennial-scale abrupt climatic flips during the last glaciation. Recently, a new project to retrieve a deep ice-core from Greenland known as NEEM for North Greenland Eemian Ice Drilling, has been launched with the main target being the last interglacial period. The new core will help us understand further details of climate changes during a period of warmth as the present. Antarctic ice cores have a unique advantage in providing recovery of longer time-scale paleclimate information and hence are regarded as a crucial pillar to examine climatic cycles on the time-scale of Earth-orbital phenomena. Since the bottom ice in Dome A is estimated to be older than a million years, a deep drilling there becomes a new focus for ice core studies. Supported by Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KZCX2-SW-354) and National Key Technology Research and Development Program (Grant No. 2006BAB18B01)     

A method for calculating palaeoclimate index in quaternary pollen－spore analysis

Ａｍｅｔｈｏｄｆｏｒｃａｌｃｕｌａｔｉｎｇｐａｌａｅｏｃｌｉｍａｔｅｉｎｄｅｘｉｎｑｕａｔｅｒｎａｒｙｐｏｌｌｅｎ－ｓｐｏｒｅａｎａｌｙｓｉｓＬｕｏＬｕｎｄｅ（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ，ＳｏｕｔｈｗｅｓｔＣｈｉｎａＮｏｒｍａｌＵｎｉ...     

博格达山西缘三葛庄凸起多期构造变形及其对博格达山隆升的响应

三葛庄凸起位于准噶尔盆地东南缘柴窝堡盆地,夹持于博格达构造带与伊连哈比尔尕构造带之间,因其地理位置特殊,三葛庄凸起的构造演化对区域构造的研究有积极作用。通过二维地震资料解释、演化剖面制作,结合前人研究成果,揭示了三葛庄凸起构造特征及演化过程。认为三葛庄凸起的形成经历了多期构造抬升,与前人对博格达山的多期隆升研究有较高的匹配。结果表明:三葛庄凸起经历三期构造运动,受构造运动控制,三葛庄凸起形成三个明显的角度不整合,包括三叠系底部不整合,侏罗系底部不整合以及古近系底部不整合。三葛庄凸起是博格达山向西的延伸段,其演化受到博格达山的控制。晚二叠世博格达山初次隆升,三葛庄凸起随之抬升,造成三叠系底部不整合。受到印支运动的影响,博格达地区晚三叠世又遭受了强烈的挤压运动,在三葛庄凸起表现为三叠系与侏罗系之间的角度不整合。新生代时期博格达山及北天山的持续隆升导致三葛庄凸起南部发生挤压沉降,沉积新生界将博格达山的西段掩盖。     

后沙峪凹陷第四纪高精度地层格架及地质意义

通过对后沙峪凹陷ZK19钻孔自然伽马测井曲线进行旋回地层分析,以古地磁测年数据为年龄锚点,建立了后沙峪凹陷第四纪0.1Ma年精度的年代标尺,为后续研究后沙峪第四纪的构造演化、气候变化提供了精细的年龄标定。通过对钻孔ZK19开展沉积相分析,将地时与沉积相分析相结合,讨论本区第四纪以来的沉积演化,以及沉积环境对第四纪新构造运动的响应。分析表明,钻孔中识别出的两次浅湖沉积,沉积时间分别为2240~2152ka,1784~1475ka,分别对应了早更新世早期的西山强烈上升时期和早更新世中期的青藏运动B幕,北京地区构造以北东向断裂活动为主导。根据后沙峪凹陷浅湖相的消亡时间,确定后沙峪凹陷的形成时间大概2080ka左右。晚更新世以来,北东向断裂表现为整体运动,两盘差异不大,后沙峪地区主要为曲流河的沉积环境。