三维地震勘探恢复性放炮法变通问题的讨论

受地物影响，炮点的理论变观方法(恢复性放炮法)只能是三维地震数据采集过程中的一种补救措施而已，它只保证了设计覆盖次数不变的目的，而不能保证道集内炮检距和方位角不变的目的。一方面，变观后要求所有的炮检距均满足最大炮检距的限定条件显得过于苛刻；另一方面，对地层倾角较大或煤层埋藏较浅的勘探区，一个区的最大炮检距允许值也不一定是一个确定的值，通常的做法是取平均值。据此，提出了三维变观80原则，即在变观炮点不多或不集中时，只要变观炮点记录中有80％的炮检距或不低于80％的道满足最大炮检距要求，就可认为变观是成功的。这种实用的变观方法，对三维地震勘探野外数据采集工作有较明确的指导意义。     

试论会计信息的作用

立足会计信息在国民经济中的地位，分析了会计信息的作用，提出了会计信息质量是建立诚信社会的保障。     

大坂山隧道地下水动态分析及对隧道作用评估

Base on the groundwater yield, water temperature and hydrochemistry change of the groundwater, we can analyze that the summer water content is obviously greater than winter water content where the in and-out wall rock of the Daban Mountain tunnel. The groundwater supply has the extensity and the seasonality. The groundwater content of the middle tunnel wall rock changes relatively steady, mainly supply through horizontal direction. And the total groundwater content is relatively little and steady in winter. The water pressure of the wall rock cranny is little. It has the fluent drainage system to dredge groundwater, which cannot constitute a threat to the tunnel lining. And the cold-proof sluice hole can normally work to drain water.     

湖北蕲春花岗岩类锆石SHRIMP年龄：大别山造山带内弱变质—未变质晋宁期花岗岩类的发现

蕲春花岗质杂岩体包括斑状二长花岗岩和花岗岩两部分,它们之间在化学性质上存在着很大的差异,前者表现为高Al 2O3(15.73%)、相对高CaO(2.46%)、Na2O含量明显高于K2O(Na2O/K2O=1.27),尤以强烈亏损重稀土元素和极强的轻、重稀土元素分馏程度[(La/Yb)N=46.8]为特征而类似于太古宙高Al2O3的TTG岩石.而后者则以较低的Al2O3含量(14.05%)、贫CaO(0.82%)、K2O含量明显高于Na2O(Na2O/K2O=0.81)为特征,轻、重稀土元素的分馏程度[(La/Yb)N=10.89]也较片麻状二长花岗岩中弱得多.两类岩石中锆石的U-PbSHRIMP年龄分别为824.6±17.6 Ma和784±20 Ma,该时代与大别山造山带内花岗片麻岩的原岩形成年龄类似.大别山造山带内弱变质-未变质晋宁期花岗岩的出现表明扬子板块印支期向北俯冲时,该花岗质杂岩处于俯冲板片的后缘,可代表造山带内扬子基底的原地露头.而岩体周围的高压变质杂岩应是折返上来的无根构造岩片,大别山造山带内高压超高压变质杂岩的出露不是整体性抬升剥蚀的结果.     

Geometric form of Haiyuan fault zone in the crustal interior and dynamics implications

The deep seismic reflection data on profile HY2 are reprocessed by the method of simultaneous inversion of velocity distribution and interface position. By the travel-time inversion with the data of the diving wave Pg and fault plane reflection wave, we determine the geometric form and velocity of Haiyuan fault zone interior and surrounding rock down to 10 km depth. The measured data show that the amplitudes have strong attenuation in the range of stake number 37–39 km, suggesting the fault zone has considerable width in the crustal interior. The results of this paper indicate that to the north of the fault zone the crystalline basement interface upheaves gradually from southwest to northeast and becomes shallow gradually towards northeast, and that to the south of the fault zone, within the basin between Xihua and Nanhua mountains, the folded basement becomes shallow gradually towards southwest. The obliquity of the fault zone is about 70° above the 3 km depth, about 60° in the range of the 3–10 km depths. From the results of this paper and other various citations, we believe that Haiyuan fault zone is in steep state from the Earth’s surface to the depth of 10 km. Foundation item: Joint Seismological Science Foundation of China (201001) and State Key Basic Research Development and Programming Project (95-13-02-02). Contribution No. RCEG200308, Exploration Geophysical Center, China Earthquake Administration.     

Large aftershocks triggering by Coulomb failure stress following the 2001<Emphasis Type="Italic">M</Emphasis><Subscript>S</Subscript>=8.1 great Kunlun earthquake

The great Kunlun earthquake occurred on Nov. 14, 2001 in Qinghai Province, China. Five large aftershocks with magnitude larger than 5.0 occurred near the Kunlun fault after main shock. Calculations of the change in Coulomb failure stress reveal that 4 of 5 large aftershocks occurred in areas with Δσ_f>0 (10^?2–10^?1 MPa) and one aftershock occurred in an area with Δσ_f=?0.56 MPa. It is concluded that the permanent fault displacement due to the main shock is the main cause of activity of large aftershocks, but not the whole cause.     

Large aftershocks triggering by Coulomb failure stress following the 2001 M_S=8.1 great Kunlun earthquake

IntroductionItisshowedbyresearchesonearthquakestresstriggeringrecentlythatsmall'static'stresschangesduetopermanentfaultdisplacementcanalterthelikelihoodof,ortrigger,earthquakesonnearbyfaults(Harris,1998).Manystudiesoftriggeringinthenear-field,particularlyofaftershocks,showthesestaticchangesaretriggeringagent(Kilb,etal,2000).ReasenbergandSimpson(1992)studiedthere-sponseofregionalseismicitytothestaticstresschangeproducedbyLomaPrietaearthquake,andtheresultsshowedthataftershockratesincreasedinre…     

Method of high-density seismic imaging ex-ploration and application samples

Introduction Now, shallow seismic reflection wave technique has been used extensively in geological ex-plorations of bridge, dam, high building and so on. Since shallow seismic reflection wave tech-nique is often implemented in industrial zone or city with dense population, the background dis-turbance including industrial noise, life noise, etc is very serious. Furthermore, the disturbance of seismic source is also serious due to short array length and offset of the method. In general, shal-lo…     

土壤的冷生构造及其对阿拉斯加土地利用的意义

Cryogenic structure (patterns made by ice inclusions) in seasonally frozen and permafrost-af-fected soils result from ice formation during freezing. Analysis of cryogenic structures in soils is essential to our understanding of the cryogenic processes in soils and to formulating land use management interpretations. When soils freeze, the freezing front moves downward and attracts water moving upward resulting in mainly horizontal lenticular ice formation. Platy and lenticular soil structures form between ice lenses in upper active layer. The reticular soil structure usually forms above the permafrost table caused by freeze-back of the permafrost. The upward freeze-back resulted in platy soil structure and the volume changes following the annual freeze-thaw cycle resulted in vertical cracks. The combined result is an ice-net formation with mineral soils embedded in the ice net. The upper permafrost layer that used to be a part of the active layer has an ice content exceeding 50% due to repeated freeze-thaw cycles over time. The mineral soils appear in blocks embedded in an ice matrix. The permafrost layer that never experienced the freeze-thaw cycle often consists of alternate layers of thin ice lens and frozen soils with extreme hard consistence and has relatively lower ice content than the ice-rich layer of the upper permafrost. Ice contents and thaw settling potentials associated with each cryogenic structure should be considered in engineering and land use interpretations.