龙门山断裂带隆起造山独特性探讨

龙门山断裂带位于四川盆地西缘;青藏高原东部;为四川盆地与松潘-甘孜地块的接触构造边界。龙门山地区海拔从东侧100 km外四川盆地的500 m突升至3 000 m高度;明显地标注了青藏高原的东部边界;其隆升机制也引起了国内外地质工作者的广泛兴趣;并且提出了多种隆升机制模型。在本次研究中;我们利用SinoProbe-02深反射地震剖面数据对龙门山地区的隆升机制进行研究;从而进一步探讨龙门山地区隆起造山的独特性;并讨论其与传统意义中的造山带的区别;认为龙门山断裂造山带为板块内部构造活动引起岩石圈隆起所形成的。本文的研究结果将使我们更深刻地了解龙门山地区的构造活动特点;并且有助于了解青藏高原东缘对印度-欧亚板块碰撞的构造响应。     

龙门山北段平通河流域地貌演化过程

龙门山位于青藏高原东缘,是青藏高原周缘山脉中陡度变化最大的山脉,也是全球气候和构造活动最为强烈的地区之一,因此成为研究构造、气候如何影响山脉地貌演化过程这一科学问题的良好素材。在位于龙门山北段的平通河流域,汶川地震导致该区强烈的隆升、剥蚀作用,对研究该区地貌演化过程具有重要的启示意义。通过对平通河流域基于DEM数据的地形坡度、水系分布、河流发育程度等的分析,并综合研究区构造特征和岩性特征,获得该流域不同区域的地貌演化方向,其中两个区域的地貌演化最为剧烈:1.平通河流域位于北川-映秀断裂和彭灌断裂之间的地区,未来将发生较快的隆升,地貌向高、陡的方向演化,河流下切作用使河谷两岸形成更加陡峭的地形;2.在北川-映秀断裂上盘附近地区,在构造和气候作用下侵蚀、搬运作用强烈,山体将被快速剥蚀削低,但在河谷两岸也会形成更加陡峭的地形。     

Middle Jurassic Coptoclavidae (Insecta:Coleoptera:Dytiscoidea) from China:a Good Example of Mosaic Evolution

<正>Adults of the aquatic coptoclavid beetles(Coleoptera:Adephaga:Dytiscoidea),described from four Middle Jurassic fossil localities in Inner Mongolia and Liaoning in northeastern China,are attributed to Daohugounectes primitives Wang,Ponomarenko and Zhang,2009,which was previously proposed after study of larvae.The generic name Timarchopsis Brauer,Redtenbacher and Ganglbauer,1889 is proposed as a substitute for the preoccupied and junior homonym Necronectes Ponomarenko,1977,non Milne-Edwards,1881. Furthermore,the subfamily name Necronectinae Ponomarenko,1977 is substituted by the available name Timarchopsinae.Daohugounectes is placed into Timarchopsinae because its adults have long,slightly apically widened tibiae and small femoral plates.The adults of this genus differ from those of other Timarchopsinae in the following features:antennae short and widened in the middle part;basal segments of protarsi not cut apically; metaventrite with a triangular plate.The larvae look like somewhat primitive forms in the subfamily Timarchopsinae.In contrast to these primitive larvae,the adults with some advanced characters can be regarded as among the most advanced forms in the subfamily Timarchopsinae,and probably represent a transition between the Timarchopsinae and Charanoscaphinae.Such mosaic evolution within Daohugounectes indicates that the evolutionary process of aquatic beetles is far more complex than previously thought.     

Jurassic Amber in Lebanon

<正>Reports of amber predating the Lower Cretaceous are unusual and scarce;they mostly refer to amber pieces of millimetric dimension.In the present study,we report the discovery of 10 new outcrops of Jurassic amber in Lebanon.Some of these had large centimetric-sized pieces of amber.The new localities are described,amber is characterized,and its infrared spectra given.Although the new Jurassic amber yielded to date no more than fungal inclusions,this material is significant and promising.The discovery of several Jurassic outcrops provides crucial information on the prevailing paleoenvironment of that time.     

苏鲁高压—超高压变质带南部花岗片麻岩—花岗岩的多时代演化

苏鲁高压－超高压变质带中，广泛分布有花岗片麻岩－花岗岩系列，有关其形成的时代和成因机制长期存在争议。岩石露头表现为强烈的片麻理，并且多数和榴辉岩及榴辉岩相岩石密切伴生。其岩石类型有变化，从斜长片麻岩－花岗闪长质片麻岩－二长花岗片麻岩演化到花岗岩。矿物和地球化学变化也较大。从残留的高压和超高压矿物及其退变质反应等。说明它们中有部分曾经历了高压－超高压变质作用。该变质部连云港地区4个二长花岗片麻岩－花岗岩岩体中精的单颗粒锆石，运用Pb-Pb法（质谱计双带源逐层发－沉积法）和U-Pb法（离子探针SHRIMP分析），获得的年龄值跨度大，从859Ma到150Ma，分别属于4个年龄段（时段），但是主要数据集中在600－859Ma和220－250Ma两个时段，锆石的形貌特征研究显示，这些花岗片麻岩－花岗岩是苏鲁高压变质带中长期演化的产物。其物质来源与古元古代，乃至太古变质表壳岩密切相关。元古代大量岩浆结晶型锆石指示了当时存在强烈的花岗岩浆活动，导致大量花岗岩类岩石的形成。古生代（加里东期）和中生代早期（印支期）分别经历了变质作用，尤其是印支期，至少一部分和榴辉岩源岩一起经历了高压－超高压变质作用，并且伴随有地壳部分熔融，引起又一次花岗岩浆活动，再生花岗岩，该区南部东海地区尤为明显，中生代晚期燕山期的岩浆，热液活动对花岗片麻岩也有影响，其中新元古代和印支期则是花岗片麻岩及至大别造山带中两个重要的地质构造时期。     

地震预报的决策问题

在下面的综述中，我们将地震预报看作是涉及经济学的跨学科问题。这种跨学科研究有助于我们融洽村去理解地震预报问题，在地震统计学方面亦如此，我们用公式将这个问题表示成为一个最优控制问题：得出发布几种类型警报的概率，我们有必要发现一个使预期的全部损失减少到最小的优化策略，损失包括维持警报和改变警报的两方面类型的花费；第一次成功的预报减少了一定数量的损失；在全部的有限时段内，损失的相加即为全部预期的损失。折扣因素包含在模型中，在文中也给出了算法和确切的解。本论文是根据Molchan在1990－1992年的研究结果写出的。     

无外业的平板仪测图教学

当恶劣的天气妨碍野外教学实习时，常常需要安排学生进行类似于野外实习的练习项目来替代，本文叙述了如何利用计算机形成的数字地面模型来增强对地形要素的认识，使虚构的平板仪测图练习的教学更具真实感。     

Large-Scale Mapping Observations of the C i (3P1-3P0) and CO (J = 3-2) Lines toward the Orion A Molecular Cloud

Large-scale mapping observations of the 3P1-3P0 fine-structure transition of atomic carbon (C i, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mount Fuji submillimeter-wave telescope. The observations cover 9 deg2 and include the Orion Nebula M42 and the L1641 dark cloud complex. The C i emission extends over almost the entire region of the Orion A cloud and is surprisingly similar to that of 13CO (J=1-0). The CO (J=3-2) emission shows a more featureless and extended distribution than C i. The C i/CO (J=3-2) integrated intensity ratio shows a spatial gradient running from the north (0.10) to the south (1.2) of the Orion A cloud, which we interpret as a consequence of the temperature gradient. On the other hand, the C i/13CO (J=1-0) intensity ratio shows no systematic gradient. We have found a good correlation between the C i and 13CO (J=1-0) intensities over the Orion A cloud. This result is discussed on the basis of photodissociation region models.