STRUCTURAL CHARACTERISTICS OF THE NIUSHOU MOUNTAIN AND ITS GEOLOGICAL SIGNIFICANCE IN CENTRAL NINGXIA

There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain, the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone, so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.     

Organic pollutants associated with macromolecular soil organic matter: Mode of binding

A study of ether-linked moieties in macromolecular bound residues of polycyclic aromatic hydrocarbons (PAH) generated in bioremediation experiments was performed using high temperature hydrolysis degradation with subsequent analysis of the products by GC-MS. This hydrolysis reaction was specifically designed to cleave ether bonds including relatively stable diarylether structures. Among the reaction products, aromatic alcohols representing typical microbiologically derived metabolites of PAH were found in addition to natural compounds. Thus, parts of the bound residues appeared to be linked within the macromolecular material by ether bonds. Model experiments with an oxidoreductase enzyme and aromatic alcohols indicate the formation of these ether bonds to be an enzyme-catalysed process.     

吉南早元古代集安群构造解析

早元古代集安群经历了三期构造变形，分别形成了三个特征各异的构造形迹组合。Ⅰ世代为层理褶皱组合，由平卧褶皱、轴面片理和韧性剪切变形带组成；Ⅱ和Ⅲ世代为片理褶皱组合，分别由各种位态的片理褶皱和轴面褶劈理、膝折面理组成；Ⅰ、Ⅱ世代的原始构造线方位均为近南北向，为近共轴叠加，但因Ⅲ世代构造的强烈改造，现今多变位为东西向。Ⅰ世代构造形迹组合的特征显示集安群的早期构造环境具有构造层次较深、以近水平韧性剪切变形作用为主导的特点。     

Late Paleozoic and Mesozoic deformations in the southwestern Primorye region

Two types of tectonic deformations indicating different geodynamic settings are defined in the southwestern Primorye region. Near-latitudinal compression forces were responsible for the oldest, Late Paleozoic deformations. The Permian stratified complexes host a near-meridional system of folds and zones of dynamothermal metamorphism, cleavage, and foliation oriented orthogonally relative to the compression. Late Proterozoic (?) mafic-ultramafic rocks are characterized by similar deformations. In the Late Permian, the deformations were accompanied by granitoid magmatism controlled by fold and cleavage structures. The younger, Mesozoic deformations produced by near-meridional compression are represented by NE-trending sinistral strike-slip faults and their structural parageneses: an ENE-trending system of folds and downdip-thrusts both superimposed on Paleozoic protostructures and manifested in Mesozoic and Cenozoic sequences. It is inferred that, at the Paleozoic-Mesozoic boundary, near-latitudinal compression was replaced by near-meridional compression, probably, in response to the corresponding change in direction of the lateral displacement of the interacting Asian continent and (or) Pacific Plate.     

Country‐rock structural fabrics as a guide to pluton emplacement depth: An example from the Hodgkinson Province,northeastern Australia

Country‐rock structures adjacent to plutons of the linear, northwest‐southeast‐trending Mt Alto Supersuite, Hodgkinson Province, northeastern Australia, are variably developed from north to south along the belt. S₃ and S₄ cleavages show close temporal relationships with pluton emplacement and are better and more widely developed around plutons in the north, whereas much weaker cleavages of the same generation are only sporadically developed to the south. Cleavage trend lines anastomose around less elongate plutons to the north but are generally truncated by more elongate plutons to the south. It is proposed that a major crustal dislocation, the Alto Fault Zone, comprises a set of subparallel structures that formed prior to granite intrusion and controlled emplacement of some plutons and their final shapes. The north‐south variation in structural relations is interpreted to reflect a corresponding variation in depth of emplacement from north to south, which resulted when post‐emplacement reactivation of the Alto Fault Zone uplifted and sinistrally displaced the northern end of the supersuite relative to the southern end. Reactivation of the fault zone after granite emplacement is supported by the truncation of some plutons.     

Timing of megakinks and related structures: Constraints from the Devonian Bunga‐Wapengo Basin,Mimosa Rocks National Park,New South Wales

The Bunga beds are bounded by faults adjacent to which are fanglomerates that form part of an early Late Devonian volcanic rift basin. Some cross‐faults acted as precursors for later regional deformation that kinked the Ordovician basement and gently folded the basin sediments in a northwest‐southeast direction. Details of the faulted junction at Picnic Point and orientation of cleavage microstructures in the fanglomerates support the dating of the north‐south regional F₂ deformation as Middle Devonian or older and the northwest‐southeast F₃ kinking as post‐early Late Devonian.     

陕西蟒岭马河地区宽坪群多期褶皱变形

据面理置换、小褶皱叠加、线理构造,以及对大中型构造的分析,再结合原生沉积构造和构造几何学分析,确定马河地区宽坪群经历了至少三期叠加变形.第一期为区域性挤压的紧闭平卧褶皱,第二期为穹窿状或长垣状褶皱.第三期为南北向开阔宽缓褶皱。查清构造为正确建立层序提供了依据.     

电刺激诱导栉孔扇贝雌核发育的相关参数的筛选

电刺激可诱导卵子雌核发育,但在海洋生物中尚无报道。为获得电刺激诱导栉孔扇贝雌核发育的最佳条件,采用正交设计的方法,分别研究了电场强度、电容、脉冲次数、卵子密度及缓冲液种类对诱导效果的影响。结果表明:(1)不同缓冲液的诱导效果差异不显著(P>0.05),但甘露醇缓冲液的诱导效果优于Zimmerman氏缓冲液和山梨醇缓冲液;最佳卵子密度为11.25×104个/mL,场强的最适范围为1.00～1.75kV/cm。最优电刺激诱导条件组合是:0.30mol/L甘露醇缓冲液,卵子密度11.25×104个/mL,脉冲强度1.20kV/cm,电容3μF,2次电脉冲。(2)应用优化后的电刺激参数诱导雌核发育,获得了最佳的诱导效果,得到的卵裂率为28.16%,胚胎存活率为98.37%。本研究首次成功应用电刺激法诱导了栉孔扇贝的雌核发育,并得到了单倍体胚胎,初步建立了栉孔扇贝中该诱导法的参数体系。     

阿尔金山东段大平沟地区褶皱构造的特征及其成因

大平沟地区位于北东向阿尔金走滑断裂北侧与东西向阿尔金北缘断裂所夹持的区域。区内出露卓阿布拉克组火山-沉积岩系,其中以灰黑色粉砂质泥岩为代表的沉积岩系出露宽度3～5km,是相邻20km的东侧喀腊大湾地区出露厚度（约1km）的3～5倍。通过野外详细的地质调查,特别是运用小褶皱分析方法、褶皱层理与轴面劈（片）理关系判别分析方法,首次对阿尔金山东段大平沟地区的卓阿布拉克组火山-沉积岩系中的沉积岩夹层沿剖面开展追索研究,恢复了大平沟地区褶皱构造的轮廓,并对其成因进行初步探讨。认为南侧喀腊达坂-阿克达坂断裂以南的元古宇碳酸盐岩系较强硬的岩层、北侧阿尔金北缘断裂以北的太古宇结晶基底的刚性岩块、以灰黑色粉砂质泥岩为代表的细碎屑岩的柔性特点、冰沟岩体隆升造成其东侧盖层向东收缩是基础,而北北东向区域挤压构造应力场作用下北东东向卓阿布拉克断裂的左行走滑造成的卓阿布拉克组沉积岩系西端的侧向挤压是褶皱形成的直接原因。