俯冲带榴辉岩的变形作用及其对俯冲-折返过程的意义   总被引：1，自引：0，他引：1  

曹毅  宋述光 《地质通报》2008,27(10):1646-1653

榴辉岩是大洋和大陆俯冲带的重要岩石类型,在研究俯冲带的形成过程、热结构、壳幔相互作用等方面有重要意义。通过对天然和实验样品中石榴子石、绿辉石等矿物的变形特征、变形机制、变形的影响因素等的综合分析,系统总结了高压变质带中榴辉岩矿物显微和超微变形研究的进展,探讨了榴辉岩的变形特征在恢复俯冲与折返过程研究中的意义及一些尚待解决的一些问题。  相似文献   

双作用水泵泡沫增压装置应用及前景分析   总被引：1，自引：0，他引：1  

彭新明  刘大军  柴尔慧  朱继东  孙友宏 《吉林大学学报(地球科学版)》2008,38(4)

双作用水泵泡沫增压装置是利用双缸双作用水泵的高压能力将低压空气和泡沫液二次增压至水泵的额定压力,并混合产生泡沫.采用BWZ-1200双作用水泵泡沫增压装置在北京地区深度为1 000 m以下的地热井钻探中,成功地克服了地热井钻进中井内漏失和洗井的难题;在极度缺水的宁夏南部地区水井钻探中,采用BWZ-1100双作用水泵泡沫增压装置解决了水井孔内严重漏失和施工用水的难题.该装置可代替价格昂贵的高压空压机实现气举反循环钻探,应用于深地热井、深水井和油气井钻探.  相似文献   

燕山构造带中段早白垩世盆地特征   总被引：2，自引：2，他引：0  

张英利  孟庆任 《吉林大学学报(地球科学版)》2008,38(4)

燕山构造带中段主要包含3个早白垩世盆地,即滦平盆地、凤山盆地、石人沟盆地.通过对盆地的沉积相分析、古水流的恢复以及盆地构造-沉积演化研究,认为燕山构造带中段早白垩世盆地发育分为三个阶段,即早期火山喷发阶段、中期强烈断陷阶段和晚期填平阶段.早期发育强烈的火山作用,形成以酸性火山岩为主的张家口组;中期盆地主体呈半地堑状,受单一边界主断层控制,盆地相互独立,盆地边缘以冲积扇砾岩和扇三角洲砂岩、砾岩沉积为主,盆地中心为湖泊细粒沉积.古流向和物源恢复结果证明,盆地沉积物主体来自于北部和/或西部的变质岩基底.盆地构造沉降和沉积充填过程主要受边界正断层的控制,断层下盘基底岩石的抬升与盆地边界正断层活动相关,从而成为盆地主要的物源区.  相似文献   

洞穴完井工艺在寿阳地区煤层气钻井中的应用   总被引：4，自引：0，他引：4  

黄勇  熊涛 《中国煤炭地质》2008,20(2):61-64

洞穴完井工艺包括钻井、完井、排水采气等工序,为提高煤层渗透率,最大限度的保证煤层气解析与运移,洞穴完井一般要求有效井径3-4m,及一定范围的破碎带。远东能源公司为开采寿阳地区15#煤层中的煤层气,部署了4口生产井．其井身设计为三开结构。钻井主要设备为T685WS顶驱车载钻机及多台不同型号的空压机,采用潜孔锤冲击钻进．以空气、空气泡沫为冲洗介质,钻进至15#目标煤层底板以下46m处完钻,然后利用可伸缩式扩孔器进行扩孔。在扩孔至距三开井底8～10m时．开始采用空气和清水憋压,通过瞬间释放压力,使煤层坍塌,如此反复,至造穴直径达到要求。由于严格按照技术标准及操作流程作业,采取的技术措施合理,4口井均已顺利投入生产,增产效果显著。可见该种洞穴完井技术的应用,不仅可以保护煤层原生结构及环境,并且还能减少煤层气射孔、压裂等环节的费用．对于煤层气井施工具有重要的经济意义。  相似文献   

Markoff链在市场预测中的应用     

周俐麟 《华东地质学院学报》1996,19(1):96-100

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200～300N高强度合成金刚石及其在钻探中的应用          下载免费PDF全文

方啸虎  张龙 《探矿工程》1996,(4):38-40

对会“打滑”地层,国内外均为难题,新研究的技术是：（１）用特殊的新构思,运用内设备,压制出可批量２供应的高强度金刚石,这种高强度金刚石可承受比目前高得多的钻压;（２）运用强力钻进的配套技术,用上述高强度金刚石制作头。  相似文献   

SOME NEW UNDERSTANDINGS OF LAND-SURFACE PROCESSES IN ARID AREA FROM THE HEIFE^*          下载免费PDF全文

Hu Yinqiao  Gao Youxi 《Acta Meteorologica Sinica》1996,10(2):233-246

The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe River Basin,Western China) is given in the paper.The following basic subjects for land-surface processes in arid areas are studied:(1) the general characteristics of the energy budget on ground surface in arid areas;(2) the parameterization of the land surface processes;(3) the interaction between oasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that the sensible heat flux in the surface energy budget is in the majority,and the latent heat flux may be neglected.The influence of atmospheric stratification stability on the turbulent transfer of energy and substance must be considered in parameterization of land surface processes in arid areas.The "cold island effect" phenomenon in oasis and the "humidity inversion" phenomenon in desert near oasis are the result of the interaction between them.The results would improve the understanding of land surface processes in arid areas.  相似文献   

Oil and gas resource assessment: The linkage between geological analysis and discovery process model results     

Lawrence J. Drew  John H. Schuenemeyer 《Natural Resources Research》1996,5(1):33-42

Two widely-used techniques to estimate the volume of remaining oil and gas resources are discovery process modeling and geologic assessment. Both were used in a recent national assessment of oil and gas resources of the United States. Parallel estimates were obtained for 27 provinces. Geological-based estimates can typically see into areas not available to discovery process models (that is areas with little or no exploration history) and thus, on average, yield higher estimates. However, a linear relation does exist between the mean estimates obtained from these two methods. In addition, other variables were found in a multiple regression model that explained much of the difference. Thus, it is possible to perform discovery process modeling and adjust the estimates to yield results that might be expected from geological-based assessments.  相似文献   

Rupture process of large earthquakes in the northern Mexico subduction zone     

Larry J. Ruff  Angus D. Miller 《Pure and Applied Geophysics》1994,142(1):101-172

The Cocos plate subducts beneath North America at the Mexico trench. The northernmost segment of this trench, between the Orozco and Rivera fracture zones, has ruptured in a sequence of five large earthquakes from 1973 to 1985; the Jan. 30, 1973 Colima event (M _s 7.5) at the northern end of the segment near Rivera fracture zone; the Mar. 14, 1979 Petatlan event (M _s 7.6) at the southern end of the segment on the Orozco fracture zone; the Oct. 25, 1981 Playa Azul event (M _s 7.3) in the middle of the Michoacan gap; the Sept. 19, 1985 Michoacan mainshock (M _s 8.1); and the Sept. 21, 1985 Michoacan aftershock (M _s 7.6) that reruptured part of the Petatlan zone. Body wave inversion for the rupture process of these earthquakes finds the best: earthquake depth; focal mechanism; overall source time function; and seismic moment, for each earthquake. In addition, we have determined spatial concentrations of seismic moment release for the Colima earthquake, and the Michoacan mainshock and aftershock. These spatial concentrations of slip are interpreted as asperities; and the resultant asperity distribution for Mexico is compared to other subduction zones. The body wave inversion technique also determines theMoment Tensor Rate Functions; but there is no evidence for statistically significant changes in the moment tensor during rupture for any of the five earthquakes. An appendix describes theMoment Tensor Rate Functions methodology in detail.The systematic bias between global and regional determinations of epicentral locations in Mexico must be resolved to enable plotting of asperities with aftershocks and geographic features. We have spatially shifted all of our results to regional determinations of epicenters. The best point source depths for the five earthquakes are all above 30 km, consistent with the idea that the down-dip edge of the seismogenic plate interface in Mexico is shallow compared to other subduction zones. Consideration of uncertainties in the focal mechanisms allows us to state that all five earthquakes occurred on fault planes with the same strike (N65°W to N70°W) and dip (15±3°), except for the smaller Playa Azul event at the down-dip edge which has a steeper dip angle of 20 to 25°. However, the Petatlan earthquake does prefer a fault plane that is rotated to a more east-west orientation—one explanation may be that this earthquake is located near the crest of the subducting Orozco fracture zone. The slip vectors of all five earthquakes are similar and generally consistent with the NUVEL-predicted Cocos-North America convergence direction of N33°E for this segment. The most important deviation is the more northerly slip direction for the Petatlan earthquake. Also, the slip vectors from the Harvard CMT solutions for large and small events in this segment prefer an overall convergence direction of about N20°E to N25°E.All five earthquakes share a common feature in the rupture process: each earthquake has a small initial precursory arrival followed by a large pulse of moment release with a distinct onset. The delay time varies from 4 s for the Playa Azul event to 8 s for the Colima event. While there is some evidence of spatial concentration of moment release for each event, our overall asperity distribution for the northern Mexico segment consists of one clear asperity, in the epicentral region of the 1973 Colima earthquake, and then a scattering of diffuse and overlapping regions of high moment release for the remainder of the segment. This character is directly displayed in the overlapping of rupture zones between the 1979 Petatlan event and the 1985 Michoacan aftershock. This character of the asperity distribution is in contrast to the widely spaced distinct asperities in the northern Japan-Kuriles Islands subduction zone, but is somewhat similar to the asperity distributions found in the central Peru and Santa Cruz Islands subduction zones. Subduction of the Orozco fracture zone may strongly affect the seismogenic character as the overlapping rupture zones are located on the crest of the subducted fracture zone. There is also a distinct change in the physiography of the upper plate that coincides with the subducting fracture zone, and the Guerrero seismic gap to the south of the Petatlan earthquake is in the wake of the Orozco fracture zone. At the northern end, the Rivera fracture zone in the subducting plate and the Colima graben in the upper plate coincide with the northernmost extent of the Colima rupture zone.  相似文献   

硅质碎屑砂岩中胶结物来源的新认识     

杨香华 《地质科技情报》1993,12(4):34-39

分析了浅埋藏砂岩的成岩环境,并从岩石学、矿物学、同位素及质量平衡估算方面论证硅质碎屑砂岩中的胶结物主要来源于砂岩浅埋藏期间的地下水,进而分析浅埋藏带内地下水的流动机制及早期胶结作用对晚期成岩作用的影响。  相似文献