黄河现代地质作用的一些基本特征和开发治理黄河的途径

经过地质历史演变,发育在秦岭和阴山之间的黄河,流域内分布有50多万平方公里的黄土及黄土类土,极易遭受侵蚀,水土流失严重,是世界罕有的多泥砂河流,具有不同于一般河流的地质作用和工程地质特性。研究黄河产生大量泥砂的地质条件,特别是第四纪地质和正在明显进行的侵蚀、搬运、沉积等地质作用,掌握黄河的工程地质特性,就有可能利用自然规律,更好地开发治理黄河。     

关于治理黄河的建议

黄河是我国的母亲河之一 ,对中华民族的兴盛和发展起到了重要的作用。但黄河水患也是我国人民的心腹大患 ,历史上多次泛滥改道 ,都造成了人民生命财产的重大损失 ,影响到社会的安定和生产力的发展。所以从有文字记载以来的历代政府都把黄河的治理作为一件大事来抓。黄河泛滥的根源在于黄土高原的水土流失 ,它使黄河成为世界上最著名的多沙河流 ,每年向下游输送的泥沙在 16亿ｔ以上。黄河出晋、陕、豫峡谷到中原平原后 ,地势突缓 ,流速骤减 ,随即卸下大量泥沙 ,使河床越积越高 ,甚至成为高出两岸平地的“悬河”。为了防止河水泛滥 ,人们不断…     

地质事件、序列和事件群

在前寒武纪变质基底和造山带中，由于多期热－构造事件的影响，以及透入性片理和构造岩的发育，造成变质深成侵入体，构造岩和表壳岩鉴别的困难，。即使表壳岩系统也因强烈的变形而不能够完全运用叠置地层学的方法进行地层划分和对比，因而事件地质学的思路和方法的应用颇为广泛。地质事件是地史演化过程中，不同于正常地质历史发展的突发性，或灾变性，或具有特殊意义的地质记录，在正确识别地质事件的性质和特征的基础上，需建立地质事件的序列，事件序列的建立包括两个步骤，首先要在野外翔实的工作基础上建立地质事件的相对序列，然后在此基础上运用多元同位素测年方法标定主要或特征地质事件的时代，建立地质事件的年代格架。地质事件群或组合则是成因上有联系，空间上相匹配，时间上有先后的一组地质事件，它比单独的一个事件更深刻地反映地质历史演化的过程和特点，正确归并和界定地质事件群在研究区域地质演化特征或进行大区域间的地质对比时具有十分重要意义。     

第四纪的主要气候事件

本文概要地回顾了第四纪的主要气候事件,包括万年尺度的冰期-间冰期旋回,千年尺度的Heinrich事件,Dansgaard-Oeschger旋回和新仙女木事件及百年尺度的小冰期.简述了这些事件特征和时限以及产生的背景.指出这些事件大部分首先发现于冰川和深海沉积物中,且集中在北半球的高纬度地带.湖泊沉积物是研究古气候突变事件及古季风变化的重要信息载体之一,今后应进一步加强研究.     

关于黄河治理若干问题的刍议

黄河是我国第二大河,是中华文明的重要发祥地。黄河流域生态环境脆弱,存在严重的干旱、洪捞和水土流失等多种地质灾害。尤其是近二十多年来黄河下游断流日趋严重,引起各方关注。正确分析黄河下游断流的原因及缓解黄河断流的对策,尤其从地质作用角度正确认识黄河的水资源和泥沙问题,为黄河综合治理决策提供科学依据。     

白垩纪至早第三纪的极端气候事件

地球科学界正在将预测未来气候变化的研究重点放到地球过去突然发生的气候变暖事件。白垩纪至早第三纪发生的极端气候事件被认为是最接近于现今的地球系统,对其研究有利于理解现今地球系统过程在碳循环快速搅动时的响应。这些气候事件主要包括：古新世-始新世最热事件（PETM,～5 5 MaBP）、早阿普第晚期和森诺曼-土仑界线的大洋缺氧事件（OAE1a,～120 Ma;OAE2,～93．5 MaBP）。PETM事件是中白垩世以来一次突然变暖事件,在10 ka年以内深海温度增加～5 ℃,表层海水温度增加 4～8 ℃,而δ¹³C至少发生 3．0‰的负偏移。目前普遍认为PETM事件是由于海洋气水化合物（CH₄）的巨量释放造成的。大洋缺氧事件（OAEs）记录了海洋环境下有机质的大量埋藏,代表了碳循环和海洋生物系统的重大搅动事件。综合大洋钻探计划（IODP）将极端气候确定为优先研究领域,将采取特定的钻探策略,在世界大洋范围内获取最低限度蚀变的新生代至白垩纪沉积物,研究精度要求达到米兰柯维奇的天文调谐时间尺度,其最终目标是定量描述过去全球气候变化,并为未来气候变化预测提供依据。     

川藏公路八宿至林芝段堆积体边坡的治理措施及其效果分析

该路段独特的自然地质条件孕育众多松散堆积体和地质灾害。为保护公路不受灾害危害,目前采用明洞、防冲刷、排水、抗滑和坡面防护工程。在研究这些防治措施和评价其效果的基础上,提出更合理的堆积体边坡防治方案。同时,为拟建川藏铁路的堆积体边坡灾害提出防治建议。     

新疆大陆基底分区模式和主要地质事件的划分

在同位素年代学和地球化学研究的基础上，概括了1982～2000年间的同位素年代学和地球化学研究成果，特别是1987～2000年"305"项目的研究成果。展现了近年来对新疆大陆前寒武纪基底同位素年代学研究的新成果塔里木北缘灰色片麻岩锆石U-Pb年龄为2600Ma，西昆仑基底石榴黑云母片麻岩中的锆石U-Pb一致年龄则为 （2048±20）Ma，阿尔金灰色片麻岩锆石U-Pb上交点年龄为（1820±277）Ma，测定了东天山星星峡群片麻岩的锆石U-Pb上交点年龄为（1404±18）Ma，与1986年的结果一致（1400±42）Ma，获得西天山温泉群、那拉提群和木扎尔特群混合岩化片麻岩中锆石U-Pb年龄分别为（821±11）～（798±8）Ma，（882±83）Ma和（707±7）Ma；基于Sm-Nd模式年龄统计结果，将新疆大陆基底分为5个区域，即塔里木大陆太古宙－古元古代（3.2～2.2）Ga基底区，昆仑-阿尔金造山带古元古代基底区（2.0～1.8）Ga，天山古中元古代基底区（2.1～1.7）Ga，准噶尔为年轻地壳基底区（1.4～0.7）Ga和阿尔泰古元古代、中新元古代复合基底区（≤2.6～2.4Ga,1.5～0.9Ga）；基于多年研究的积累，并综合了国内外一些可以应用的同位素年代学研究结果，提出以塔里木太古宙大陆地核向南、北逐步增生的新疆大陆地壳基底演化模式；确定了新疆大陆地壳构造演化中15次主要地质事件的时限为（3000～3200）Ma；2800Ma；2600～2500Ma；2200Ma；2000～1700Ma；1400Ma；1000Ma;；800Ma；700～>500Ma；520～480Ma；450Ma；360～300Ma；300～250Ma；210～135Ma；65～5Ma。这些同位素年代学和Nd同位素示踪研究结果无疑将成为进一步探讨新疆大陆地壳构造演化的一些重要依据。     

21世纪:关于黄河治理的战略构想

黄河——中华民族的母亲河.她在孕育着中华民族文明的同时,也给中华民族带来深重的灾难.据史载,自公元前602年至公元1938年的2540年间,黄河下游就决溢达1500多次,其中造成大的改道26次.波及范围,北抵天津,南至江淮,总面积25万km~2.因此,黄河安危,事关大局,成为历朝历代统治者治国安邦的头等大事.     

Delta progradation and chenier formation in the Huanghe (Yellow River) delta,China

To clarify Holocene development of the Huanghe (Yellow River) delta and the relationship between delta progradation and chenier formation, detailed sediment analyses and high-resolution radiocarbon dating were done on borehole samples taken from two sites on the present Huanghe; H9601 (Latitude 37°40.5′N and Longitude 118°28.7′E with an altitude of +5.5 m) and H9602 (Lat. 37°47.8′N and Long. 118°54.3′E, +4.8 m). Downcore changes of sediment facies and accumulation rate show that delta progradation occurred at least twice during ca 2.6–1.2 C-14 yrBP and 1855–present at the two borehole sites. These phases of progradation correlate with Superlobes 6 and 7 and Superlobe 10 respectively, of ten superlobes composing the Holocene Huanghe Delta shown by C. Xue (Historical changes in the Yellow River delta, China, Marine Geology 113, 321–329, 1993). The boundary of these sediments at H9602 is sharp and erosional, and correlates with cheniers located between borehole sites on the delta plain. The diastem period between these phases of progradation almost coincides with the periods when the river mouth of the Huanghe was located in the northwestern part of the Bohai Sea during 1048–1128 AD (Superlobe 8), and the Jiangsu region facing the Yellow Sea during 1128–1855 (Superlobe 9). This suggests that chenier formation and delta progradation are linked, and controlled by sediment supply and river course shifts of the lower reaches of the Huanghe.     

Optically Stimulated Luminescence (OSL) Chronology of the Dehenglong Landslide from Longyang Gorge to Liujia Gorge along Upper Yellow River, China

Giant landslides are common along the upper Yellow River from Longyang Gorge to Liujia Gorge, and some of them even blocked and dammed the upper Yellow River. Chronology is inevitable in studying the mechanism of giant landslides. Controversy exists about the chronology of those giant landslides, and some have not yet dated. The Dehenglong landslide is the largest one among them. In this study, OSL samples were collected from lacustrine silty sediments and loess directly overlying the landslide sediments, as well as fault sediments related to the landslide. This landslide yielded an age of 89 ± 8 ka, which is identical with the fault age of 73 ± 5 ka at two sigma errors. The agreement of a topographic analysis and the absolute age of landslides imply that the formation of the Dehenglong landslide is strongly correlated with the tectonic activity.     

Microplastic pollution in Yellow River,China: Current status and research progress of biotoxicological effects

This study aims to comprehensively assess the environmental risks of microplastics in the Yellow River, achieving the following results through comprehensive research. The average microplastic abundances in the river waters and sediments are 5358–654000 n/m³ and 43.57–615 items/kg, respectively, and there are fewer microplastics in water samples than in sediments. Microplastics in the study area can be divided into five types according to their occurrence morphologies, namely fragments, foams, films, fibers, and particles. The most widely distributed pollution types in sediments include debris, fibers, and particles. In contrast, fibers are the dominant type in water samples, accounting for 68.18% –98.93%. The chemical components of the microplastics include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride. The microplastics are in four colors, with white accounting for a higher proportion. The grain size of the microplastics in tributaries or lakes of the Yellow River is less than 2 mm, which makes them liable to enter organisms for enrichment. Furthermore, the sources of the microplastics are closely related to agricultural and industrial production and biological activities in habitats and exhibit seasonal and hydrological characteristics. The microplastics in the study area show the adsorption of metals and nonmetals to different degrees, which increases the pollution risks of heavy metals combined with microplastics. In addition, microplastics can accumulate in organisms in the Yellow River and cause physical, biochemical, and other damage to aquatic organisms, thus further posing carcinogenic risks to human beings. Therefore, it is necessary to study, monitor, and control the pollution and effects of microplastics in the Yellow River, in order to provide theoretical references for the control of pollution and ecological risk of microplastics in the river.©2021 China Geology Editorial Office.     

Study on the runoff and sediment-producing effects of precipitation in headwater areas of the Yangtze River and Yellow River,China

Natural runoff observation fields with different vegetation coverage were established in the Zuomaoxikongqu River basin in the headwater area of the Yangtze River, and in the Natong River basin and the Kuarewaerma River basin in the headwater area of the Yellow River, China. The experiments were conducted using natural precipitation and artificially simulated precipitation between July and August to study the runoff and sediment-producing effects of precipitation under the conditions of the same slope and different alpine meadow land with coverage in the headwater areas. The results show that, in the three small river basins in the headwater areas of the Yangtze and the Yellow Rivers, the surface runoff yield on the 30° slope surface of the alpine meadow land with a vegetation cover of 30% is markedly larger than that of the fields with a vegetation cover of 95, 92, and 68%. Furthermore, the sediment yield is also obviously larger than the latter three; on an average, the sediment yield caused by a single precipitation event is 2–4 times as large as the latter three. Several typical precipitation forms affecting the runoff yield on the slope surface also influence the process. No matter how the surface conditions are; the rainfall is still the main precipitation form causing soil erosion. In some forms of precipitation, such as the greatest snow melting as water runoff, the sediment yield is minimal. Under the condition of the same precipitation amount, snowfall can obviously increase the runoff yield, roughly 2.1–3.5 times as compared to the combined runoff yield of the Sleet or that of rainfall alone; but meanwhile, the sediment yield and soil erosion rate decrease, roughly decreasing by 45.4–80.3%. High vegetation cover can effectively decrease the runoff-induced erosion. This experimental result is consistent in the three river basins in the headwater areas of the Yangtze and Yellow Rivers.     

Geochemistry of metals in sediments from the mainstem of the Yellow River, China

Sediment samples at 10 locations in the mainstem of the Yellow River were taken in 1994. Five forms (exchangeable, carbonate, organic, Fe/Mn oxide and residual) of metals were extracted by the Tessier method. The total contents and contents of the five forms of 16 metal elements (Li, Na, K, Ca, Sr, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Al) were determined by ICP-AES. In sediments of the Yellow River, except for Na, mobile elements (such as K, Ca) do not show a negative correlation with the immobile elements. Alkaline metals (Li, Na, and K), Ti, and Al exist mainly in the residual form. The exchangeable forms of alkaline-earth elements (Ca, Sr, and Ba) are the highest, and their residual forms go up with the increase of the period in the periodic table of elements. Half of Mn exists in the residual form, and its non-residual forms exist mainly in carbonate and oxide forms. Except Mn, the iron group elements (Fe, Co, Ni, V, Cr) mainly exist in the residual and oxide forms. High carbonate content of Ca does not cause high contents of other elements in carbonate form, showing that chemical weathering is not strong in the area.     

The cassiterite-polymetallic sulfide deposits of Dachang (Guangxi,People's Republic of China)

The Dachang mining district is the second largest producer of Sn in China and an important source of other metals. The known mineralizations can be divided into four groups: (1) cassiterite + Cu-Fe-Pb-Zn sulfides and sulfosalts, (2) Zn-Cu skarn, (3) Sb-W veins and (4) residual and placer concentrations of Sn and Fe oxides. Most orebodies are hosted by Upper Devonian calcareous, marly and quartzitic formations in spatial association with Cretaceous Yanshanian magmatites. A characteristic feature is the occurrence of stratiform, lens-shaped orebodies which appear to represent the root zone of overlying stockwork mineralizations. The metallogeny of the district may be interpreted in terms of an Upper Devonian Sn and polymetallic concentration with subsequent remobilization and, possibly, the introduction of additional elements during the late stages of the Yanshanian magmatism.     

Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments in the Yellow River Estuary, China

Concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments of the Yellow River Estuary (YRE). The isobath-parallel tidal and residual currents play important roles in the variation of PAH distribution, such that the contamination level of PAHs in fine-grained sediments is significantly higher than in the relatively coarse grain size sediments. Both diagnostic ratios and principal component analysis (PCA) with multivariate linear regression (MLR) were used to apportion sources of PAHs. The results revealed that pyrogenic sources are important sources of PAHs. Further analysis indicated that the contributions of coal combustion, traffic-related pollution and mixed sources (spills of oil products and vegetation combustion) were 35, 29 and 36 %, respectively, using PCA/MLR. Pyrogenic sources (coal combustion and traffic-related pollution) contribute 64 % of anthropogenic PAHs in sediments, which indicates that energy consumption could be a predominant factor in PAH pollution of YRE. Acenaphthylene and acenaphthene are the two main species of PAHs with more ecotoxicological concern in YRE.     

Wavelet-based variability of Yellow River discharge at 500-, 100-, and 50-year timescales

Water scarcity in the Yellow River, China, has become increasingly severe over the past half century. In this paper, wavelet transform analysis was used to detect the variability of natural, observed, and reconstructed streamflow in the Yellow River at 500-, 100-, and 50-year timescales. The periodicity of the streamflow series and the co-varying relationships between streamflow and atmospheric circulation indices/sunspot number were assessed by means of continuous wavelet transform (CWT) and wavelet transform coherence (WTC) analyses. The CWT results showed intermittent oscillations in streamflow with increasing periodicities of 1–6 years at all timescales. Significant multidecadal and century-scale periodicities were identified in the 500-year streamflow series. The WTC results showed intermittent interannual covariance of streamflow with atmospheric circulation indices and sunspots. At the 50-year timescale, there were significant decadal oscillations between streamflow and the Arctic Oscillation (AO) and the Pacific Decadal Oscillation (PDO), and bidecadal oscillations with the PDO. At the 100-year timescale, there were significant decadal oscillations between streamflow and Niño 3.4, the AO, and sunspots. At the 500-year timescale, streamflow in the middle reaches of the Yellow River showed prominent covariance with the AO with an approximately 32-year periodicity, and with sunspots with an approximately 80-year periodicity. Atmospheric circulation indices modulate streamflow by affecting temperature and precipitation. Sunspots impact streamflow variability by influencing atmospheric circulation, resulting in abundant precipitation. In general, for both the CWT and the WTC results, the periodicities were spatially continuous, with a few gradual changes from upstream to downstream resulting from the varied topography and runoff. At the temporal scale, the periodicities were generally continuous over short timescales and discontinuous over longer timescales.     

西江干流河水主要离子及锶同位素地球化学组成特征

水环境中锶（Sr）含量及其同位素组成特征的研究有助于认识区域水文地球化学特征及流域盆地岩石风化速率等地球化学行为,因此河流环境中Sr的地球化学行为是地球化学研究的重要课题之一。对中国南方西江干流及其支流河水主要阴阳离子及sr同位素组成进行了分析,发现其水化学组成主要以Ca^2＋、Mg^2＋、HCO3^-和SO4^2-离子为主,分别占阴阳离子组成的80％以上。郁江河水具有较高的Sr同位素比值（^87St／^86Sr=0．71049）和较低的Sr含量（0．0263mg／L）,而西江河水具有较低的Sr同位素比值以及较高的Sr含量,其Sr含量变化范围在0．0667．0．187mg／L之间,平均含量为0．136mg／L;Sr同位素比值变化范围在0．70856．0．70936之间,平均比值为0．70894。与世界主要河流水体中Sr含量平均值（0．078mg／L）及Sr同位素比值（^87Sr／^86Sr=0．7119）相比,西江干流水体具有较高的Sr含量及较低的Sr同位素比值。两条河流河水中主要离子及Sr的来源存在显著差异,西江干流河水中的主要溶解离子及Sr同位素主要源于碳酸盐岩（石灰岩和白云岩）的风化作用,主要受黔江及其上游红水河等化学组成所控制,而郁江则主要受碎屑岩风化作用的影响;同时,中上游地区的酸沉降及人类活动的输入可能导致西江干流水体受到一定程度的污染,而郁江受污染程度则相对较小。     

The Alluvial Geoarchaeology of the Sanyangzhuang Site on the Yellow River Floodplain,Henan Province,China

The Sanyangzhuang site, Henan Province, China, has a 12‐m‐deep stratigraphic sequence with remains from the Tang (A.D. 618–907), late Western Han (ca. 140 B.C.–A.D. 23), Warring States (475–221 B.C.), Late Neolithic or Early Bronze Age (ca. 5000–1500 B.C.), Middle Holocene, and Early Holocene times. All of the paleosols are deeply buried. We investigate four issues relevant to the archaeology of the lower Yellow River Valley. First, we confirm that the Yellow River flowed north toward Bohai Bay throughout most of the Holocene. Second, we expand understanding of Holocene paleoenvironments. Long episodes of landscape stability punctuated by brief periods of Yellow River flooding represent the dominant environmental pattern. Third, we investigate how the complex relationships between climate, culture, and the environment affect Yellow River flooding, which in turn shapes Chinese civilization and history. Flooding in late Western Han times affected a vast area of north‐central China; this catastrophe contributed to the downfall of the late Western Han Dynasty. Finally, this research sheds light on the role of Yellow River alluviation in site burial and preservation. Rapid alluviation in the region has buried many archaeological sites. Settlement pattern research needs to take seriously the limitations placed on site visibility in quickly aggrading floodplains. However, gentle alluviation has also preserved settlements and entire landscapes providing unparalleled opportunities to explore the archaeological and historical record of the lower Yellow River Valley.