Genesis types of the Neoproterozoic Molar tooth structures in the southeastern Jilin and eastern Liaoning provinces and its research significances

Molar tooth (briefly called MT) carbonate is one of the Proterozoic carbonates with enigmatic sedimentary structure. According to the morphology of MT, it can be divided into two main genesis-morphology types, i.e., autochthonous and allochthonous, and each type can be further divided into a series of subtypes. The autochthonous MT can be divided into filamentous (MF1), ribbon, nodular and dotted type (MF4), in which the ribbon one can be subdivided into simple vertical (MF2) and complex ribbon (MF3), broken ribbon by storm in situ (MF5) and MT within nodular limestone (MF6). Allochthonous MT includes conglomerate clasts and horizontal detritus. Studying on the links between MT and the host rocks on five stratigraphic sections in the southeastern Jilin and eastern Liaoning indicates that the morphology of MT is closely related to host rocks, and seven genetic types by relationships between MT and the host rocks with facies interpretations are classified and discussed in this paper. The sedimentary environments of MT formation will be diverse if their morphologies are different.

     

汶川地震断裂带科学钻探工程2号孔350～800m井段的钻探泥浆气体组分变化

以汶川地震断裂带科学钻探工程(WFSD)2号孔350～800 m井段的钻探泥浆中某些气体组分测定数据,以及2009-10-10～2010-05-24钻孔附近断裂带范围内里氏震级ML≥3.5的目录、断裂带岩芯岩性为基础,探讨钻探泥浆脱气气体组分异常与构造环境、地震活动的关系。研究结果表明,660～680 m井段附近岩石破碎程度达到最大,各气体归一值也出现明显的正、负异常,得到的最大、最小值所对应的井段也是面波震级MS 3.0以上余震的频发处,气体异常多数出现在岩石的裂隙、破裂面、断层处。     

Interpretation of the EPR parameters through investigating the local lattice deformations for the two Pt3+ centers in ZnWO4

The local lattice distortions and the electron paramagnetic resonance (EPR) parameters (anisotropic g factors and the hyperfine structure constants) for the two Pt³⁺ centers in ZnWO₄ are theoretically investigated by utilizing the perturbation formulas of these parameters for a 5d ⁷ ion under rhombically elongated and compressed octahedra. The elongated (and compressed) centers are ascribed to the [PtO₆]^9? clusters on Zn²⁺ site suffering the axial elongation of 0.01 Å (and compression of 0.02 Å) along Z axis and the planar bond angle variations of 7.4° (and 7.8°), respectively, due to the Jahn–Teller effect. The above local lattice deformations may considerably cancel the original large axial elongation (~0.31 Å) and perpendicular rhombic angular distortion of the host [ZnO₆]^10? cluster and yield more regular [PtO₆]^9? clusters in the impurity centers. The calculated EPR parameters based on the above lattice deformations show good agreement with the experimental data, and the local structures of the impurity centers are discussed.     

地气溶胶勘查地球化学方法及其在金窝子金矿中的应用

论述了将气溶胶理论和技术应用于深部隐伏矿找矿的基本问题。深部矿物质能够穿越矿体覆盖层到达地表,主要是通过气体携带质粒向上迁移,这种迁移发生的基本条件是质粒可以稳定悬浮于气体中并随之流动。气溶胶理论表明,直径在0.1~2.5μm的质粒在气体中最稳定,质粒过小或过粗都不可能较长时间悬浮于气体中。气溶胶的另一个理论要点是,直径小于2.5μm的固体质粒不可能通过机械碾磨方式形成。这两个气溶胶理论要点是深部金属矿生成气溶胶级别的质粒并进入气体向上迁移的基础。将气溶胶理论和技术应用于新疆金窝子隐伏金矿床找矿试验,结果表明,在210隐伏矿上方和矿体倾斜面上方有明显的金异常和金伴生元素异常,异常程度高,出露面积大。这一实验证明了通过提取吸附于地表土壤中的地气溶胶质粒,并分析其元素含量的气溶胶找矿方法,具有良好效果。     

南极布兰斯菲尔德海峡沉积物的C_5～C_(15)烃类化合物

本文研究了南极布兰斯菲尔德海峡表层沉积物中Ｃ５－Ｃ１５烃类化合物的分布特征，其中包括正构烷烃、异构烷烃、环烷烃和芳烃化合物。所有试样中均含有大量的芳烃物苯、甲苯、二甲苯和三甲苯，其中甲苯占绝对优势，为总烃量的７５－８１％。对一些有机化合物进行了多元统计分析，如Ｑ和Ｒ模式系统聚类分析和主因子分析。Ｑ模式的最长距离法反映了９０１航次和首次南大洋样的差异。９０１航次样经旋转后三个因子的等值线趋向上，各站位间有着明显的差别，其中Ｇ－２７站均趋向极端值     

南海西南次海盆深部结构研究进展与展望

西南次海盆位于南海渐进式扩张的西南端,共轭陆缘结构和残留扩张脊保留完整,是研究南海深部结构和动力学机制的关键区域。前期研究发现,西南次海盆洋陆过渡带较窄、同扩张断层发育、地震反射莫霍面不清晰、具有慢速扩张等特征。然而,由于不同探测方法获取的地壳结构具有多解性,使得西南次海盆洋陆转换过程、慢速扩张洋壳结构与增生模式以及龙门海山岩石性质与地幔成因机制等基础科学问题尚存争议。为此我们建议在西南次海盆开展地质取样获取海山岩石样品,确定其年龄与性质,分析扩张后海山形成的深部动力过程;并对关键构造部署高精度的地震反射/折射联合探测,结合岩石物理分析,对西南次海盆进行构造成像和物质组成参数正反演,以实现壳幔尺度的地震学透视,为探索西南次海盆洋陆转换过程和洋壳增生模式提供重要的地球物理证据,以丰富和完善南海的动力学演化模式。     

Reproductive morphology ofEucheumagelatinae (Esper) J. Agardh (Solieriaceae,Gigartinales, rhodophyta)

Eucheuma gelatinae (Esper) J. Agardh has vegetative and reproductive features distinguishing it from other species ofEucheuma. The occurrence of reproductive nemathecia containing carpogonial branches, auxiliary cells and post-fertilization stages including gonimoblast and pericarp initiation, fusion cell formation stages and carposporophyte development are described and ilustrated for the first time for this species. Contribution No. 2380 of the Institute of Oceanology, Chinese Academy of Sciences.     

Monitoring periodically national land use changes and analyzing their spatiotemporal patterns in China during 2015–2020

Journal of Geographical Sciences - High-resolution mapping and monitoring of national land use/cover changes contribute significantly to the knowledge of the interaction between human activities...