New discovery of Palaeontinid fossils from the Middle Jurassic in Daohugou, Inner Mongolia (Homoptera, Palaeontinidae)

Three new species of fossil Palaeontinidae are described from Daohugou Village, Inner Mongolia, China: Daohugoucossus shii sp. nov., D. parallelivenius sp. nov., D. lii sp. nov. The diagnosis of Dao- hugoucossus Wang, Zhang and Fang, 2006 is revised. These materials are the first complete fossil palaeontinids in the Middle Jurassic of the world. Based on observation of these new specimens, Sc of this new genus has the following combined characters: joined with R at base, diverged near M separa- tion, coalesced with R before the nodal line, extended beyond the nodal line and fused with R1 before distal end. Due to the Sc characteristics mentioned above, the genus Liaocossus Ren, Yin and Dou, 1998 can be well distinguished from “Ilerdocossus-complex”.     

Biostratigraphical significance of the Devonian Sinoleperditiini (Ostracoda)

In South China and its adjacent areas, leperditiid ostracodes from the Devonian are very abundant. They have in common a trailing chevron muscle scar (tv: Fig. 1(a)) which uninterruptedly extends ventrally with passing geological time, and range through most De-vonian. The tribe Sinoleperditiini was proposed by Wang (1994) for these ostracodes since other leperdi-tiids from North America, Europe, Siberia and else-where bear the non-trailing chevron muscle scar (v: Fig. 1(b)) and range from…     

Framework and evolution of the middle Paleozoic orogenic belt between Siberian and North China Plates in northern Inner Mongolia

A middle Paleozoic subduction-collision orogenic belt between the Siberian and North China Plates has been recognized in Xilinhot-the south of Sonid Left Banner-Erdaojing area, northern Inner Mongolia, China. It comprises five subunits: mélange belt, foreland deformation belt, molasse and littoral basin, are diorite series and syncollision granitoid series. Evolution history of the orogenic belt can be divided into subduction stage (500-400 Ma) and collision stage (400-320 Ma). The formation of the orogenic belt caused the convergence between the Siberian and North China Plates during the late Devonian. Suture zone corresponding to the mélange belt extends from Erdaojing, Qagan Ura to Honggor. Project supported by Fok Ying Tung Education Foundation in Hong Kong.     

蒙古中南部地区的上地幔P波速度结构

利用中蒙国际科技合作专项项目在蒙古中南部地区布设的69个宽频带地震仪在2011年8月—2013年7月所记录的远震波形数据,采用波形相关方法在0.02~0.1 Hz的频段内拾取了18551个有效的P震相相对走时残差数据,进一步采用有限频走时层析成像的方法,反演获取了蒙古中南部下方深达800 km的P波速度结构.结果显示：肯特山下方的低速异常极有可能是推测中的肯特山地幔柱的反映;呼斯坦瑙鲁和曼达尔戈壁西边的低速异常可能与杭爱山高原下的地幔柱或地幔对流有关联;戈壁滩的低速异常带可能和达里甘嘎火山有相同的热来源,可能是该区火成岩存在的深部原因,也可能是戈壁滩及其周边地区地幔柱或下地幔热物质上涌的表现.     

用遗传算法反演内蒙古中西部地区的Q值和场地响应

在前人研究的基础上,本文用遗传算法反演了内蒙古中西部地区(106.85°E～113.13°E,36.69°N～41.57°N)的Q值和场地响应。发现用Atkinson方法得到的非弹性衰减系数c(f)与频率f无关,品质因子Q(f)是仅与频率有关的线性强函数,而与非弹性衰减系数无关。另外在将c(f)等参数代入moya方法求台站场地响应的过程中发现,有些基岩台站有放大作用。     

南黄海与晋冀内蒙交界区地震相关现象及其应用

本文利用１９００年以来Ｍｓ≥４．７地震目录，系统分析了南黄海及沿岸地区与晋冀内蒙交界地区中强地震此起彼伏，遥相呼应的同步涨落现象，利用这一现象，可能对这２地区未来二三年内地震活动趋势预测提供一个方面的证据，本文给出了预测方案，报道了应用实例，并就有关问题进行了讨论。     

Identifying the flow pattern and natural recharge at a strategic groundwater resource in the Dornogobi Province,Mongolia

The strategic project of economic development in the Dornogobi Province in Mongolia is dependent on water supply. Thus a comprehensive hydrogeological characterization was focused on the Upper Cretaceous multi-aquifer system north of Sainshand city. A conceptual model was developed to discover the groundwater flow pattern essential to correct the setting of the numerical model of groundwater flow created using MODFLOW to assess the natural recharge of the aquifer. The conceptualization was based on geological and hydrogeological characterization. However, the evaluation of hydrochemistry proved to be the key factor revealing the principal feature of the groundwater flow pattern, which is the presence of preferential flow zones. These zones allow for intensive transfer of relatively fresh Na(Mg,Ca)?HCO₃-dominated groundwater into discharge areas, where it leaks into the Quaternary aquifer. The numerical model suggested an enormous natural recharge of 22 100 m³/d, originating in 64% of the preferential flow zones.     

The Upper Devonian orbital cyclostratigraphy and numerical dating conodont zones from Guangxi,South China

The hierarchically organized laminae, bundles, bundlesets and superbundlesets which correspond to a sub-Milankovitch, obliquity or precession, eccentricity and long eccentricity cyclothems, respectively, have been distinguished from the Upper Devonian Fras-nian-Famennian (F-F) transitional carbonate successions deposited in the carbonate-basin and slope facies of Guangxi, South China. The durations of cyclothems are 8000-10000a, 16667a or 33333a, 100000a and 400000a, respectively. The ratio of eccentricity to precession, eccentricity to obliquity, and long eccentricity to eccentricity is 1 : 6, 1 : 3 and 1 : 4 in the Devonian, respectively. Orbital cyclostratigraphical studies show that the durations of the conodont falsio-valis Zone, transitans Zone, punctate Zone, Lower hassi Zone, Upper hassi Zone, jamieae Zone, Lower rhenana Zone, Upper rhenana Zone, linguiformis Zone, Lower triangularis Zone, Middle triangularis Zone and Upper triangularis Zone are 0.4, 0.4, 0.4, 0.3, 0.4, 0.2, 0.8, 0.6, 0.8, 0.3, 0     

基于双差定位方法的内蒙古中西部地区地震精确定位

针对测震台网定位存在偏差的问题,采用双差定位方法,对2008—2019年9月内蒙古测震台网及周边台站记录的内蒙古中西部地区4410个地震事件进行重新定位.研究表明,利用双差定位方法重新定位后地震分布更集中,更符合内蒙古中西部地区的地质构造特征,定位精度显著提高.     

内蒙古东部地区一维地壳速度结构分析

采用内蒙古测震台网2009—2016年记录的内蒙古东部地区131个地震资料,使用速度拟合、分区扫面、折合走时方法,反演得到该区域速度模型：v₁=6.10 km/s、v_Pb=6.72 km/s、v_n=8.05 km/s、H₁=23 km和H₂=16 km。东部模型检验结果显示,定位残差均值较华南模型和2015内蒙最优模型有明显的降低,且更加均匀稳定;东部模型与编目定位震中差较华南与编目、2015内蒙最优模型与编目和华南与编目震中差均值降低1 km左右。可见,东部模型更适合内蒙古东部地区。     

The Kellwasser events in the Upper Devonian Frasnian to Famennian transition in the Toc Tat Formation,northern Vietnam

Upper Devonian carbonates of the Toc Tat Formation in the Si Phai Pass area of Dong Van District, northern Vietnam were deposited in carbonate platform, slope, and basin environments. These carbonates yield abundant conodonts indicative of the Palmatolepis nasuta, Pa. linguiformis and Pa. triangularis zones, the Frasnian–Famennian stage boundary being identified by the first occurrence of Pa. triangularis. Two positive carbon isotope excursions are recognized, the lower excursion peaking in the interval of the lower to middle Pa. nasuta Zone, whilst the upper excursion peaks just above the local Frasnian–Famennian boundary. Based on the biostratigraphy, these excursions equate to the Lower and Upper Kellwasser events. Locally, tentaculitoid taxa (Nowakia, Styliolina, Homoctenus, and Metastyliolina?) are abundant in the interval of the Pa. nasuta Zone, but show a drastic decline in abundance before the Lower Kellwasser Event, and only two taxa survived into the Famennian.     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods' abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella's photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods.     

南北同枯场景下南水北调中线丹江口水库供水调度方式

南北同枯场景下南水北调中线丹江口水库供水调度是保障水源工程有效供给、优化配置供水水源的重要课题,如何科学制定不同供水对象的供水水量、兼顾水源区及受水区用水需求、充分发挥丹江口水利枢纽的调蓄作用,是南水北调中线工程功能效益发挥的关键.以南水北调中线水源工程丹江口水库为研究对象,深入分析了中线工程通水后丹江口水库供水现状及面临的技术难题,从而提出南北同枯场景的判别标准及相应水库供水调度的方法,揭示了汉江中下游、清泉沟和南水北调中线供水对水库起始供水水位的响应机理,提出"蓄丰补枯、均衡减少"的方法是南北同枯场景下丹江口水库的供水调度方式,不同供水起始水位及供水方式情况下供水调度仿真结果表明,本文所得结论可为丹江口水库在实际运行中制定调度方案提供参考.     

Revision of Cyprinus maomingensis Liu 1957 and the first discovery of Procypris-hke cyprinid(Teleostei,Pisces) from the late Eocene of South China

Fossil cyprinids from the upper part of the upper Eocene Youganwo Formation of Maoming, Guangdong, China were first studied in 1957 by Liu, who referred the only specimen to the genus Cyprinus as a new species, C. maomingensis. And this was suggested as one of the earliest records for fossil cyprinids. Unfortunately, this specimen is poorly preserved and reveals no more morphological information than its serrated last unbranched dorsal and anal fin rays. Recently, some new specimens were unearthed from the same locality, where C. maomingensis was discovered. In addition to the serrated dorsal and anal fin rays, these new materials also show that the pattern and shape of their pharyngeal teeth obviously differ from that of Cyprinus but resemble that of Procypris. However, its number of the branched dorsal fin rays and number of vertebrae are much less than that in Procypris. Morphologically, these specimens are closer to Procypris than to Cyprinus. This is the first report of fossil Procypris-like fish, and it implies that Procypris-like fish is an early member of the Tribe Cyprinini sensu stricto(sensu Yang et al., 2010) and the origin of this group can be traced back at least to the late Eocene.     

Palynological record during the Pleistocene (between 1.05 Ma and 0.36 Ma) from ODP1144, northern South China Sea

This paper presents the pollen record from the lower section of ODP1144 (depth 501.3-225.7 m, ca. 1.05-0.36 Ma). Two pollen zones (PA and PB) and eleven pollen subzones are recognized. Within zone PB, the 11 pollen subzones (PB21-11) are defined according to the pine, fern and herb variations, and are equivalent to the marine isotope stages 21-11 (MISs 21-11). The interglacial periods are typified by an increase in pine pollen and fern spores, and a decrease in herbaceous pollen, while the patterning during the glacial periods is just the opposite. During the interglacial periods, pollen assemblages were dominated by pine similar to those of the present day, suggesting that the paleoenvironment of the interglacial periods was similar to that of the present day, whereas the glacial periods are marked by an increase in herbaceous pollen, mainly Gramineae and Cyperaceae, indicating that grassland covered the exposed continental shelf when sea level declined. Increased Artemisia percentages and the highest     

New stylophorans (Echinodermata) from the upper Cambrian of Guangxi,South China

This paper describes for the first time the cornute stylophorans (Echinodermata) in China. The new material came from the Guole Formation of the Furongian (Late Cambrian) in the Guole area of Jingxi, Guangxi Province, South China. These new cornute specimens are preserved in situ and found along with well-preserved trilobites and brachiopods. One new species, Phyllocystis jingxiensis sp. nov., is proposed to accommodate these unusual materials. The new species is defined by the small, heart-shaped theca with the frame composed of ten narrow, smooth and thick marginal plates, three adoral plates and distinctive zygal and aulacophore. Both supracentrals and infracentrals are polygonal-outlined. The marginal plate M1' on the inferior face extends posteriorly to form zygal that possesses a broadened proximal end and the proximal portion joining with the conjunction between M4 and M5 on the inferior face. Aulacophore comprises ten segments at its proximal part and is conical at the middle part (named stylocone). Its distal portion is rather long and bears conspicuous ambulacrum grooves. Tectals are horizontally arranged on superior face and obliquely arranged on inferior face. Both cothurnopore and anal pyramid are vaguely seen on the right anterior corner and the extremity of theca's superior face.     

The tectonic implications of Solundian (Upper Devonian) magnetization of the Devonian rocks of Kvamshesten, western Norway

The allochthonous Old Red Sandstone of Kvamshesten, western Norway, records polyphase orogenic deformation, and palaeomagnetic results from both the Devonian sediments and mylonites associated with the basal thrust define a syn- (to post-) tectonic magnetization withD = 218°,I = +3° and₉₅ = 9.7°. The corresponding pole position (lat. 21°S, long. 324°E) suggests a Late Devonian/Early Carboniferous magnetization age (Solundian), and probably dates the time of thrust movements.     

The geobiological formation process of the marine source rocks in the Middle Permian Chihsia Formation of South China

The Chihsia Formation is one of the four sets of regional marine hydrocarbon source rocks from South China.In the past two decades,detailed geochemical and sedimentological studies have been carried out to investigate its origination,which have demonstrated that the high primary productivity plays a primary role in the deposition of sediments enriched in the organic matter.However,the mechanism of this high productivity and the path of the deposition and burial of the organic matter have always been a mystery.Based on the previous studies on the Shangsi Section in Guangyuan City,Sichuan Province,we proposed that the development of the equatorial upwelling due to the sea level rise is responsible for the relatively high productivity in the Chihsia Formation.The sea waters with high nutrient were transported by the sub-surface currents along the equator.High organic carbon flux was deposited on the deeper shelf,and then decomposed by bacteria,leading to the occurrence of anaerobic respiration.The metabolism of the microorganisms consumed the dissolved oxygen in waters,which was in favor of the preservation of the organic matter.This suggested geobiological model integrating with paleoclimatology,paleoceanography and geomicrobiology will help us to understand the causes of this particular sedimentary sequence.     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods’ abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella’s photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods. Supported by NSFC Innovation Research Group Program (Grant No. 40621002), MOE Innovative Research Team Program (Grant No. IRT0546), the National Natural Science Foundation of China (Grant Nos. 40472020, 40730209, 40802005 and 40872001) and SINOPEC Project (Grant No. G0800-06-ZS-319)     

Luminescence dating of a gigantic palaeolandslide in the Gobi-Altay mountains, Mongolia

In an attempt to date a palaeolandslide that took place along the Baga Bogd Massif, in Mongolia, the infrared stimulated luminescence (IRSL) method has been applied to lacustrine silty sediments directly overlying the landslide mass. The IRSL age estimates obtained on alkali feldspar grains (>40 μm) and polymineral fine grains (4–11 μm) provide a minimum age for the landslide event. The IRSL ages on alkali feldspars corrected for long-term fading using the protocol of Mejdahl (1988, 1989) suggest that the palaeolandslide occurred at the beginning of the Last Interglacial. These are in good agreement with the ¹⁰Be cosmogenic dates obtained on faulted and abandoned alluvial fans in the Gobi-Altay mountains. This study demonstrates for the first time that the IRSL dating method can successfully be applied for establishing landslide chronologies.