甘肃临夏盆地中新世地层及哺乳动物化石

甘肃临夏地区中新世哺乳动物化石引起学术界的重视。经过考察、发掘,哪现了大量的化石标本。由于发表的文章多为单篇,较分散,笔者收集整理,对材料进行了研究,认为甘肃临夏地区在近直余年来是全国发现中新世材料最多的地区,且有极高的研究价值,填补了我国中新世哺乳动物化石中的部分空白。     

Environmental indicators from comparison of sporopollen in early Pleistocene lacustrine sediments from different climatic zones

Two lacustrine sporopollen records obtained from the Qaidam Basin (in the non-monsoonal region) and the Linxia Basin (in the monsoonal transition zone) indicate that during the early Pleistocene open forest-steppe/steppe vegetation developed in the Qaidam Basin, while in the Linxia Basin an open cypress forest-steppe shifted to a conifer/conifer-steppe and then to open forest-steppe vegetation. Existing sporopollen records from the Chinese Loess Plateau (CLP) (in the monsoonal region) indicate that around the Sanmen Paleolake open forest-steppe shifted to pine/conifer-broadleaved mixed forest. The conifer cover then changed to a subtropical evergreen broadleaved forest distributed around the Nihewan Paleolake. These changes suggest that wetter conditions progressed from western China to the east, and the climate became more humid than that of today indicating a stronger Asian summer monsoon during the early Pleistocene.     

A bizarre tandem-horned elasmothere rhino from the Late Miocene of northwestern China and origin of the true elasmothere

Although the modern Indian and Javan rhinos have a single horn on their noses,the extinct one-horned rhino Elasmotherium was a source for the legendary unicorn,because the latter had a very long horn on its forehead and lived with the prehistoric human beings who drew its images on cave paintings.Elasmothere rhinos first appeared in South Asia in the Early Miocene,but the origin of Elasmotherium has been unclear.All other elasmotheres have a weak or strong nasal horn,whereas Elasmotherium seems to lose the nasal horn of its ancestors and to get a huge frontal horn apparently abruptly.Here we report the first discovered skull of Sinotherium lagrelii from the Late Miocene red clays in the Linxia Basin,northwestern China.This skull has an enormous nasofrontal horn boss shifted posteriorly and a smaller frontal horn boss,which are connected to each other,indicating an intermediate stage for the single frontal horn of Elasmotherium.Morphological and phylogenetic analyses confirm that Sinotherium is a transitional taxon between Elasmotherium and other elasmotheres,positioned near the root of the giant unicorn clade and originated in a subarid steppe.The posteriorly shifted nasal horn has a more substantial support and the arched structure of the nasofrontal area is an adaptation for a huge horn.     

甘肃临夏盆地8～6 MaBP的构造变化

甘肃临夏盆地毛沟剖面上半部高精密度古地磁测年结果表明该剖面磁极性年龄为4.34～13.07 MaBP,其中东乡组、柳树组与何王家组的年龄分别为13.07～7.8 Ma,7.8～6.4 Ma和6.40～4.34 MaBP.该测年结果与文献[1]测得的结果基本一致.临夏盆地6.40～6.16 MaBP湖泊沉积环境突变,8 MaBP左右毛沟剖面地层磁偏角发生明显偏转,盆地中王家山剖面银川沟背斜大约在6 MaBP左右发生倾斜与变形,这表明临夏盆地8～6 MaBP经历了一次强烈的构造运动.     

晚新生代元谋盆地演化与河谷发育研究

元谋盆地是在晚新生代青藏高原与云南高原隆起过程中形成的众多断陷盆地之一,流经元度盆地的龙川江和金沙江。其河谷发育与盆地演化具有密切关系,通过对元谋盆地及其邻区的层次地貌与相关沉积的分析研究,认为,始新世晚期￣中新世晚期是夷平面形成时期,中新世晚期￣３．４０ＭａＢＰ前后是第一级剥蚀面形成时期;元谋盆地形成于３．４０ＭａＢＰ前后第一级剥蚀面解体过程中,其后盆地经历了３．４０￣１．７８ＭａＢＰ的古湖形成     

Recent Advances in the Small Mammal Biostratigraphy and Magnetostratigraphy of Lanzhou Basin

The consensus view among geologists is that the Lanzhou Basin sequence of sediments contains the Oligocene/Miocene boundary, but where this occurs is unknown. Indeed, this is the crux of the issues concerning mid-Tertiary paleontology in Asia: what fauna corresponds with this time? What turnover events or distinctive taxa signal the beginning of the Miocene epoch? Once known, this will be of broad usefulness because vertebrate-bearing deposits are widespread in Asia and can be used to date basin sediments. Lanzhou and other basins permit a means of correlating to the time scale by using fauna and paleomagnetic data locally, and ultimately radiometric data from distant localities, to develop a precise biochronology. Herein, we summarize faunal constraints, primarily those of small mammal taxa, on correlation of the Lanzhou magnetozone sequence to the magnetic time scale. We conclude that the lower part of the Xianshuihe Formation contains the Oligocene/Miocene boundary, and that the top of the formation, both in the south and north parts of the basin, is middle Miocene in age. Rodents from lower white sand units of the Xianshuihe Formation, correlate to the Xiejia assemblage of the Xining Basin, Qinghai Province, and are early, but not earliest, Miocene age. The implication for rodent faunas of the epoch boundary is that they retained a mainly "Oligocene" composition, and that other presumed late Oligocene assemblages may be, in fact, early Miocene in age. The Lanzhou appearance of Proboscidea is 19-18 Ma, as expected.     

维也纳盆地石油地质特征与勘探潜力探讨

通过分析维也纳盆地的地层和断裂发育特征, 总结该盆地的石油地质特征, 并对该盆地的勘探潜力进行探讨。维也纳盆地是位于东阿尔卑斯与西喀尔巴阡褶皱带之间的走滑拉分盆地, 具有波西米亚和古生界至中生界双重基底, 构造演化分为侏罗纪伸展断陷、白垩纪至早中新世逆冲推覆和中新世中期盆地拉分3 个阶段。维也纳盆地自下而上形成3 个构造层, 分别为侏罗系至白垩系原地沉积层、二叠系至古近系外来推覆体沉积层和新近系沉积层。维也纳盆地发育上侏罗统泥灰岩和古近系页岩两套烃源岩, 上侏罗统启莫里阶Malmian 组泥灰岩是主要的烃源岩。储层分布于三叠系至新近系中新统的各个层段, 其中最重要的储层为中新统浅水三角洲相砂岩, 其油气储量占总储量的 76%, 其次为三叠系亮晶白云岩。区域盖层为新近系页岩。综合评价认为, 中生界外来推覆体(复理石浊积岩和三叠系白云岩)和原地中生界沉积物(即第二、第三构造层)是最重要的勘探潜力区。     

Late Miocene–early Pleistocene paleoproductivity variations of the Lop Nor in the Tarim Basin and its implications on aridification in Asian Interior

Extensive lacustrine deposits in the eastern Tarim Basin provide records of climate change influenced by the westerly winds and the Asian monsoon. To char- acterize the evolution of climate change in this region, we analyze elemental concentrations of barium （Ba） from the Ls2 drill core of Lop Nor, a paleo-lakebed located in the eastern Tarim Basin. Biogenic Ba concentrations from this drill core display a large-amplitude oscillation that gener- ally follows a pattern similar to that of Artemisia content and ostracod assemblages, suggesting that is may serve as an index for climate change experienced in the basin. Our results indicate that biogenic Ba is especially sensitive to precipitation. All climatic proxies served in this study vary significantly over late Miocene to early Pleistocene time period. Strong aridification of eastern Tarim in the late Miocene to the early Pliocene may be attributed to a lati- tudinal shift in the westerly winds, which would have resulted in more moisture transported to southern and eastern Tibet. The growth of the Himalaya and Tibetan Plateau may have acted as an orographic barrier that blocked moisture sourced in the south from the northern margins of the plateau. We link weaker aridification in the late Pliocene to an increased intensity of the Indian Monsoon.     

Development of a pediment on western slopes of Liupan Mountain related to the Neotectonic Uplift

The late Cenozoic uplift of Qinghai-Xizang Plateau plays an important role in adjacent geomorphic evolution and depositional environments. Liupan Mountain, located at the northeast margin of Qinghai-Xizang Plateau, has different landforms on the east and west sides. Recently, a pediment, which lies above the highest terrace of the Yellow River at the northeast edge of Longzhong Basin, has been described. The paleomagnetic measurements indicate that the pediment had developed at least 1.8 MaBP and its age is in accordance with that of the peneplains near Lanzhou and Linxia, in the southwest of Longzhong Basin. The results suggest that the Longzhong Basin lying to the west of Liupan Mountain had been subject to erosion and developed an extensive pediment; this pediment is named the Gansu Period Peneplain. It also indicates that Qinghai-Xizang Plateau and Liupan Mountain were uplifted strongly at that time, which caused not only the end of pediplanation but also Yellow River appearance and loess accumulation.     

Magnetostratigraphy and pavleo-environmental record of Tertiary deposits of Lanzhou Basin

The Tertiary deposits of the Yongdeng section, the Lanzhou Basin were studied by means of magnetostrati-graphy. The magnetostratigraphic sequences from Paleocene to Miocene were established, and the time scale for the corresponding stratigraphy and mammalian faunas was also established by referring to their correlation to the GPTS of BKSA95 (The geomagnetic polarity time scale which was thoroughly revised and updated by Berggreen et al. in 1995). In the end the paleoenvironmental records and their relationship with the uplifting of the Tibetan Plateau were discussed. The results are as follows. The top boundary of the Xiliugou Formation is dated to be 51 Ma, i.e. Eocene. TheYehucheng Formation covers the time span of 51-31.5 Ma, i.e. from late Early Eocene to early Early Oligocene. The Xianshuihe Formation covers the time span of 31.5-15 Ma, i.e. from Early Oligocene to Middle Miocene. The lower member of the Xianshuihe Formation spans from 31.5 to 20.0 Ma, i.e. from Early Oligocene to early Early Miocene. The middle member is from 20.0 to 16.5 Ma, i.e. in the middle Early Miocene.     

柴达木盆地中新世中期以来构造的运动学模型

柴达木盆地是位于青藏高原内部的山间盆地,盆地新生代的变形受到两侧山体隆升的主导.通过贯穿盆地地震剖面的精细构造解释和分析,依据生长地层的结构,我们认为自中新世中期以来昆仑山前冲断楔体以平均4.7 mm/a的速度向盆地逆冲,导致盆地南斜坡向昆仑山方向仰冲;这为东昆仑山北麓出露的倾向北向南逆冲的多条断层和盆地南部向南逆冲的断层控制的断层相关褶皱作用所证实.盆地北部祁连山前冲断楔体向盆地方向逆冲,导致盆地北部向北逆冲的断层在地表形成北翼陡、南翼缓的断层相关褶皱背斜,向北逆冲的断层在盆地东部局部位置出露地表.昆仑山前冲断楔体和祁连山前冲断楔体的楔顶已经相向冲断至盆地中部,并造成第四系的变形.     

Juvenile hominoid cranium from the terminal Miocene of Yunnan, China

Fossil apes are known from several late Miocene localities in Yunnan Province, southwestern China, principally from Shihuiba (Lufeng) and the Yuanmou Basin, and represent three species of Lufengpithecus. They mostly comprise large samples of isolated teeth, but there are also several partial or complete adult crania from Shihuiba and a single juvenile cranium from Yuanmou. Here we describe a new, relatively complete and largely undistorted juvenile cranium from the terminal Miocene locality of Shuitangba, also in Yunnan. It is only the second ape juvenile cranium recovered from the Miocene of Eurasia and it is provisionally assigned to the species present at Shihuiba, Lufengpithecus lufengensis. Lufengpithecus has most often been linked to the extant orangutan, Pongo pygmaeus, but recent studies of the crania from Shihuiba and Yuanmou have demonstrated that this is unlikely. The new cranium reinforces the view that Lufengpithecus represents a distinct, late surviving lineage of large apes in the late Miocene of East Asia that does not appear to be closely affiliated with any extant ape lineage. It substantially increases knowledge of cranial morphology in Lufengpithecus and demonstrates that species of this genus represent a morphologically diverse radiation of apes, which is consistent with the dynamic tectonic and biotic milieu of southwestern China in the late Miocene.     

临夏回族自治州少数民族传统体育挖掘与整理的意义和价值

临夏回族自治州少数民族传统体育内容形式丰富多样,健身娱乐功能突出,所需场地器材简易,己成为临夏少数民族开展全民健身活动的重要途径和社会生活的有机组成部分．基于访谈和调查结果,对临夏回族自治州少数民族传统体育项目挖掘与整理的现实意义和价值做了探讨和研究．以期对推进临夏回族自治州少数民族传统体育的挖掘整理工作具提供理论依据和参考．     

临夏方言中心区双音节连读变调的实验研究

临夏方言属于官话方言区中原官话片陇中方言的小片.临夏方言在长期与少数民族的交往中形成了自己独特的特点,其双音节的连读变调更是独具特色.文章主要采用实验语音学的方法,对临夏方言中心区的双音节连读变调的具体情况进行分析.研究结果表明,临夏中心区双音节词的调值变化区域多在3度4度之间,变调类型大体可以归纳为5种.所以在整体上看,临夏中心区双音节词的变调形式较为简单,并且去声为中降调,阳平为中升,因此在听感上临夏方言的语调显得较为平直.     

珠江口盆地13.8Ma陆架边缘三角洲与陆坡深水扇的“源-汇”关系

揭示南海北部被动大陆边缘盆地浅海陆架与深水陆坡之间的沉积响应关系,在等时地层格架内对陆架三角洲、上陆坡复合水道和陆坡重力流沉积进行综合分析.研究结果表明:相对海平面变化、陆架多级坡折演化、陆源碎屑供给强度以及陆架海洋水动力作用等四大因素控制着陆架-陆坡体系的发育;珠江口盆地中新统韩江组13.8 Ma形成的界面为三级层序界面,该时期低位域晚期发育陆架边缘三角洲,三角洲前缘带主体分布在白云凹陷北坡的陆架坡折处,随着物源供给,前缘带不断进积,陆架向陆坡方向生长,在多级坡折、坡度变化以及沉积物自身重力影响下,前缘带沉积物由牵引流搬运向重力流搬运转化,在陆坡复合水道搬运通道的作用下向白云凹陷深水区内再沉积,形成低位域晚期多坡度控制的滑塌体、碎屑流-浊流深水扇沉积,构成南海北部珠江口盆地特殊的陆架-陆坡“源-汇”响应系统;该沉积响应具有短暂性、突发性和连续性等特点.     

Rock magnetic studies on the hominoid-bearing sediments at Zhupeng, Yuanmou Basin, southwestern China and its paleoclimatic significance

It has been proposed that paleoclimatic changes and tectonic events strongly affect hominoid evolution. The Zhupeng section at Yuanmou Basin, southwestern China, with the hominoid-bearing fluvial-lacustrine sediments, is an ideal natural laboratory to test this hypothesis. This study provided an integrated magnetic study, including low-frequency susceptibility, the anisotropy of magnetic susceptibility, temperature-dependent susceptibility, hysteresis loops, isothermal remanent magnetization, and anhysteretic remanent magnetization, on samples from the Baozidongqing section at Zhupeng. Results show that the dominant mag- netic carrier is hematite, with minor amount of magnetite. Both the composition and concentration of magnetic miner- als strongly correlate with the lithostratigraphy. At least eight short-term events defined by higher concentrations of magnetite were identified. These short events reflect that the subtropical dry-hot climate is similar to today＇s climate. Basing on the lithostratigraphic and rock magnetic results, we suggest that Yuanmou Basin was in a steady deposition environment from about 11 to 7 Ma, which is characterized by alternating of long-term torrid-humid climate and short-term dry-hot climate. Our study provides invaluable environment information for understanding the climate shift and the relationship between paleoenvironment and hominoid evolution in southwestern China during late Miocene.     

土地利用规划耕地预测方法对比研究——以甘肃省临夏市为例

以甘肃省临夏市1998-2008年耕地面积的土地利用变更调查数据为基础,采用头脑风暴法、趋势分析法、一元线性回归法、移动平均法、GM(1,1)模型法对临夏市历年的拼地面积的变化情况进行分析,并得出移动平均法更适用于临夏市周边其有相似地貌特征地域的耕地量的预测,为临夏市未来耕地的变化提供了一种较为可靠的预测模型.     

柴达木盆地构造圈闭特征与含油气性

构造是柴达木盆地油气分布的主要控制因素,构造圈闭的形成、发展与演化对油气聚集有着重要的控制作用.柴达木盆地构造圈闭以背斜、断背斜、断鼻和断块为主,主要分布在七个泉—油砂山—东柴山、红沟子—南翼山—碱石山—落雁山、冷湖零号—冷湖七号—马海以及中内部等4个NW走向的密集分布区带内.构造圈闭的平面展布主要受应力作用状况、构造变形程度和断裂发育状况等因素控制.平衡剖面复原结果表明构造圈闭主要开始形成于古新世和中新世,主要定型于中新世、上新世和第四纪.喜山运动控制了柴达木盆地西部地区构造圈闭的形成与演化过程.圈闭含油气性综合分析表明,生烃凹陷附近的古构造圈闭和同沉积构造圈闭应该是下一步油气勘探的重点领域.     

喀什凹陷的成因及找油方向

通过对喀什凹陷的基底结构和变形特征分析认为，喀什凹陷在侏罗纪—中新世期间的沉降主要与塔拉斯—费尔干纳断裂的拉分作用有关；上新世以后的变形受天山和昆仑山山前逆冲作用控制；凹陷北部斜坡带的变形机制主要是山前重力滑动和山麓逆冲作用。根据与喀什凹陷有类似成因联系的中亚含油气盆地的油气勘探经验预测，喀什凹陷的油气主要赋存于山前构造带向斜盆地内部的低凸起中，下第三系膏盐层为主要勘探标志层。