闽西南地区晚三叠-中侏罗世沉积岩矿物和元素地球化学特征：对盆地构造背景转变的约束

闽西南地区上三叠统-中侏罗统文宾山组、梨山组和漳平组经历了一次大规模的海侵-海退事件.泥岩的常量元素分析和ICP-MS微量、稀土元素测试结果显示的地球化学特征表明,该套沉积物源岩主要为沉积岩和花岗岩.文宾山组和梨山组沉积物源岩是来自被动大陆边缘物源区和酸性岛弧源区的沉积岩和花岗岩(Rb＞ 100×10-6; K20＞ 1％;Hf=5.38×10-6～ 14.17×10-6;La/Th=1.64 ～4.94).漳平组源岩来自酸性岛弧源区和长英质、基性岩混合物物源区的花岗岩(Rb＞300×10-6; K20 ＞2％;Hf=3.75 ×10-6～6.64×10-6; La/Th =2.73 ～4.21).砂岩骨架成分研究表明,文宾山组物源主要来自火山弧造山带;梨山组和漳平组物源来自火山弧造山带和岩浆弧物源区,这与泥岩地球化学特征显示的物源区吻合.不同时代岩性岩相组合、泥岩地球化学特征和砂岩矿物成分特征,以及样品在Zr-Th、La-Th-Sc、Th-Co-Zr/10构造环境判别图解中的位置,说明文宾山组沉积物沉积于既有被动大陆边缘特性,也有大陆岛弧(∑REE =22.51×10-6～152.6×10-6;LREE/HREE=7.21～ 15.01,8Eu =0.69 ～0.90,La/Yb =5.64～ 16.93;(La/Yb)N=3.66～10.99)特性的弧后伸展盆地.梨山组沉积物沉积于靠近大陆岛弧的活动大陆边缘(∑REE=140.4×10-6 ～335.5×10-6,LREE/HREE =9.52～15.90,δEu=0.48 ～0.62,La/Yb=11.04 ～21.13;(La/Yb)N =7.17 ～ 13.72),同时具有被动大陆边缘(∑REE=115.4×10-6～383.4×10-6,LREE/HREE=8.30 ～20.27,δEu =0.55～0.67,La/Yb=8.42 ～30.12;(La/Yb)N =5.47 ～ 19.56)特性的弧后挤压盆地.漳平组沉积物沉积于靠近大陆岛弧的活动大陆边缘(∑REE=98.34×10-6～260.5×10-6,LREE/HREE=11.28～19.38,δEu=0.56 ～0.64,La/Yb=10.19 ～23.91;(La/Yb)N =6.62 ～15.52)特性的弧后挤压盆地.     

西藏班公湖-怒江缝合带西段去申拉组泥质硅质岩的发现及其地质意义

首次在班公湖-怒江缝合带西段去申拉组中发现了泥质硅质岩,呈2个层位产出。为探讨泥质硅质岩的沉积环境、成因及与班-怒特提斯洋西段构造演化的关系,进行岩石学和地球化学分析,结果显示,第一层位泥质硅质岩Al_2O_3/(Al_2O_3+Fe_2O_3)、Ce/Ce~?、(La/Ce)_N、V/(Ni+V)、Ce/La、Ce_(anom)、Eu_(anom)平均值分别为0.60、0.80、1.24、0.72、1.84、-0.08、0.01,第二层位泥质硅质岩相应比值平均值分别为0.65、0.83、1.16、0.77、1.97、-0.07、0.02。结合泥质硅质岩的Fe_2O_3/TiO2-Al_2O_3/(Al_2O_3+Fe_2O_3)、(La/Ce)N-Al_2O_3/(Al_2O_3+Fe_2O_3)、Hf/3-Th-Ta关系图解,表明第一、二层位泥质硅质岩形成于活动大陆边缘,沉积时水-岩界面为水体分层不强烈的厌氧环境。U-Th、Zn-Ni-Co、La-Ce、La/Yb-REE关系图解和稀土元素特征指示了第一、二层位泥质硅质岩为热水成因,热水活动与玄武岩岩浆活动有关,第二层位泥质硅质岩沉积时热水活动更强烈。去申拉组泥质硅质岩的岩石学、地球化学特征表明,狮泉河地区班-怒特提斯洋至少在早白垩世仍具有一定规模的洋盆,其闭合时间应晚于约109Ma,进一步限定了洋盆的闭合时间。     

内蒙古乌兰沟埃达克岩锆石U-Pb年龄及构造环境

内蒙古中部贺根山缝合带的梅劳特乌拉蛇绿岩中,新发现乌兰沟埃达克岩,岩性为花岗闪长岩。LA-ICP-MS锆石UPb测年结果表明,乌兰沟埃达克岩的侵位年龄为279.3±1.4Ma,其形成时代为早二叠世。乌兰沟埃达克岩SiO_2含量为65.92%~69.65%,MgO为1.34%~2.16%,Al_2O_3为15.30%~17.33%,Na_2O/K_2O值为3.95~14.09,Sr=359.60×10~(-6)~734.00×10~(-6),Yb=0.83×10~(-6)~2.02×10~(-6),Y=6.65×10~(-6)~12.84×10~(-6);富集K、Rb、Sr等大离子亲石元素,亏损Nb、Ta、Ti、P等高场强元素;稀土元素总量为32.18×10~(-6)~65.41×10~(-6),明显较低,轻、重稀土元素分馏明显,(La/Yb)N值为2.84~7.56,无明显Eu异常,显示出高硅埃达克岩(HSA)的地球化学特征。该埃达克岩具有岛弧型岩浆岩特征,形成于俯冲带岛弧环境,可能为洋内俯冲洋壳+俯冲深积物部分熔融并与上覆地幔楔橄榄岩反应成因。根据乌兰沟埃达克岩与梅劳特乌拉蛇绿岩的时空分布与演化特征,贺根山缝合带在早二叠世可能存在洋内俯冲作用。     

松树南沟金矿区玄武安山岩锆石U-Pb年代学地球化学及其动力学意义

对松树南沟金矿区大面积出露的玄武安山岩进行了年代学和地球化学研究,厘定了成岩时代探讨了岩石形成的构造环境。研究表明,玄武安山岩中岩浆锆石LA-MC-ICP-MS U-Pb加权平均年龄为450±2 Ma,MSWD=1.8,属晚奥陶世。主量元素显示玄武安山岩样品Si O2含量介于51.1%⁵5.4%,平均52.8%,属中-基性的钙碱性火山岩。岩石稀土总量较低,ΣREE为29.6×10-655.4%,平均52.8%,属中-基性的钙碱性火山岩。岩石稀土总量较低,ΣREE为29.6×10-6¹63.8×10-6,平均114.2×10-6。岩石的(La/Yb)N为3.70163.8×10-6,平均114.2×10-6。岩石的(La/Yb)N为3.70¹2.17,平均7.73,显示出轻稀土元素相对富集、重稀土元素相对亏损的特征。样品δEu为0.6112.17,平均7.73,显示出轻稀土元素相对富集、重稀土元素相对亏损的特征。样品δEu为0.61⁰.89,平均0.78,具有弱的负铕异常。微量元素显示出富集大离子亲石元素(Rb、Th、U),相对亏损Nb、Ta、Ti,无明显的Zr和Hf异常,具有岛弧玄武岩的地球化学特征。该文认为松树南沟金矿区玄武安山岩形成于北祁连洋向南侧中祁连陆块俯冲的构造环境,其成因可能与洋壳俯冲环境下流体交代的岩石圈地幔部分熔融有关。     

青藏高原班公湖地区晚白垩世埃达克岩年代学、地球化学及构造意义

青藏高原西部班公湖地区的日松岩体和甲维酸性岩脉位于班公湖蛇绿混杂岩带南侧,岩石类型为英云闪长岩,花岗闪长玢岩和花岗闪长岩,显示中钾钙碱性-高钾钙碱性过渡的特征.元素地球化学组成表明,岩石均具有埃达克岩特征,表现为高的SiO₂(63.05%~70.72%)、高Al₂O₃(≥15%)、低MgO(0.97%~2.33%)＜3%、高Sr含量(380.4×10-6~625.0×10-6)、Sr/Y(＞35)、低HREE、Y(5.64×10-6~13.80×10-6)和Yb(0.46×10-6~1.25×10-6),轻重稀土分异明显(17.09＜(La/Yb)_N＜48.51).日松花岗闪长岩体LA-ICP-MS锆石U-Pb年龄为82.0±1.1 Ma;甲维近东西走向的花岗闪长岩脉和近南北走向的花岗闪长玢岩脉LA-ICP-MS锆石U-Pb年龄分别为90.7±1.2 Ma和82.9±1.2 Ma.日松和甲维处埃达克岩均富钾贫钠,低Cr、Ni,高Th、Th/La、Th/U、Rb/Sr以及相对低的Sr/Y和高Mg#(43.09~54.35)等特征显示其为玄武质岩浆底侵加厚下地壳部分熔融形成.91~82 Ma的埃达克岩形成于后碰撞初期阶段,为中特提斯洋闭合后板内热隆伸展、壳幔相互作用的产物,可以作为班公湖地区由板块构造体制转向板内构造体制的标志.      

青藏高原昌都地区马查拉组成煤期构造背景与聚煤模式

为了恢复昌都盆地内早石炭世聚煤环境,对马查拉组内碎屑岩微量元素、稀土元素进行测试,结果显示的地球化学特征（La/Yb=10.04~15.62 μg/g;La/Th=1.33~3.17 μg/g;Hf=4.58~13.90 μg/g）表明,该套沉积岩物源为来自被动大陆边缘沿物源区的沉积岩和酸性岛弧源区的花岗岩。马查拉组在Zr-Th、La-Th-Sc、Th-Co-Zr/10构造环境判别图解中的位置（∑REE=193.96 μg/g,LREE/HREE=6.29;δEu=0.61;La/Yb=13.17;（La/Yb）_N=8.55）,说明马查拉组沉积既有活动大陆边缘的特性,又有向大陆岛弧过渡的趋势。马查拉组主体是一套沉积于大陆边缘的浅海-海陆交互环境的沉积岩,层内煤层多发育在海侵体系域内,属于海侵成煤。煤层具有层数多、厚度薄、连续性差、聚煤中心分散的特点。研究区沉积时,其西缘的澜沧江洋盆已经发生俯冲,其聚煤模式属于活动大陆边缘弧后盆地成煤。研究成果既可以细化早石炭世特提斯演化过程,又有助于揭示昌都地区煤炭资源的赋存规律。      

中祁连西段野马山岩基年代学、地球化学特征及地质意义

野马山岩基位于中祁连地块西段,由早期岩体(花岗闪长岩、斑状二长花岗岩)和晚期岩体(二长花岗岩)组成,二者呈侵入接触。LA-ICPMS锆石U-Pb定年表明,早期岩体侵位时代为中奥陶世((469.0±1.3)Ma),晚期岩体侵位时代为晚奥陶世((450.0±1.0)Ma)。早期岩体Si O2=59.8%~64.2%,K2O/Na2O1,且A/NKC=0.8~1.0,为准铝质岩石;微量元素相对富集Rb、U、Th和亏损Ba、Nb、Ta、Sr、P、Ti;稀土总量为97.7×10-6~185×10-6,且(La/Yb)N=5.57~12.47,LREE/HREE=7.7~11.3,具轻重稀土分馏明显,轻稀土富集,弱Eu负异常(δEu=0.66~0.89)特征。晚期岩体Si O2=69.8%~76.5%、K2O/Na2O=1.2~1.7、A/NKC=1.0~1.1,属弱过铝质花岗岩;稀土总量为78.97×10-6~244.92×10-6,轻重稀土分馏不明显((La/Yb)N=1.90~5.72),强Eu负异常(δEu=0.11~0.24)。岩石地球化学特征表明,野马山岩基早期岩体为I型花岗岩,形成于俯冲环境,晚期岩体为高分异的I型花岗岩,形成于后碰撞环境。结合岩体产出的区域构造位置及区域地质演化,认为早古生代北祁连洋发生了双向俯冲,野马山岩基为其向南俯冲碰撞的产物。     

西藏安多纳茸矿区石英闪长玢岩成因及地质意义

纳茸矿区位于南羌塘南缘东段,是认识班公湖?怒江成矿带构造?岩浆?成矿作用的理想窗口.以纳茸矿区内出露的石英闪长玢岩为研究对象,对其进行了系统的锆石U-Pb定年、全岩地球化学、锆石原位Hf同位素及全岩Sr-Nd同位素研究.结果显示纳茸矿区石英闪长玢岩形成于晚侏罗世（158~155 Ma）,属于钙碱性系列,具有高Sr（178×10-6~1 086×10-6）含量以及高Sr/Y（15~82）和（La/Yb）_N（17~34）比值,亏损重稀土元素（如Yb=1.05×10-6~1.45×10-6,Y=10.50×10-6~14.78×10-6）,整体呈现出与埃达克质岩石相似的地球化学特征.石英闪长玢岩样品低MgO、Cr、Ni,高Th和Th/U,锆石ε_Hf（t）值在-1.7~4.3之间,（87Sr/86Sr）_i比值为0.705 93~0.706 81,ε_Nd（t）值在-2.67~-0.49之间.结合区域地质资料,指示其是俯冲背景下加厚下地壳部分熔融的产物.将本文研究结果与南羌塘中西段的同期岩浆作用相结合,表明班公湖?怒江洋向北俯冲至羌塘地体之下,在晚侏罗世形成了超过1 200 km的近东西向岩浆弧.纳茸矿区与多龙矿集区内成矿岩体具有相似的锆石Hf同位素组成,锆石微量元素具有高Ce/Ce*、Eu/Eu*比值,全岩微量元素具有较高的Sr/Y、V/Sc比值,显示纳茸矿区具有较好的成矿潜力.      

内蒙古查干拜兴晚石炭世埃达克岩的成因及其洋内俯冲作用的约束

由于缺少可靠的埃达克岩石的发现和系统研究,内蒙古索伦地区有无洋内初始弧火成岩组合和洋内俯冲作用尚不清楚,制约了古亚洲洋东段古生代古大洋俯冲消亡过程的进一步认识.本文报道在内蒙古苏尼特右旗蛇绿混杂岩带中新发现的晚石炭世埃达克岩,岩性为英云闪长岩.锆石LA-ICP-MS U-Pb定年显示,查干拜兴埃达克岩的形成时间为322.3±5.2 Ma,时代为晚石炭世.该埃达克岩属于低钾拉斑系列-中钾钙碱性系列岩石,SiO2含量为65.57％～67.89％,Al2O3为15.48％～16.55％,MgO为0.76％～1.63％,Na2O/K2O为2.39～18.09,Sr为371×10-6～486×10-6,Yb为0.60×10-6～1.76×10-6,Y为4.87×10-6～7.82×10-6.相对富集大离子亲石元素K、Rb和Sr等,亏损高场强元素Nb、Ta、Zr、Ti和P,稀土元素总量(∑REE)较低(22.83×10-6～80.63×10-6),贫重稀土元素,无明显的Eu异常,显示了典型埃达克岩的地球化学特征.查干拜兴埃达克岩具有岛弧型岩浆岩特征,形成于俯冲带岛弧环境,可能为俯冲洋壳部分熔融而形成的埃达克质熔体,经俯冲带上升过程中与地幔楔橄榄岩发生相互作用而形成.根据查干拜兴埃达克岩与区域石炭纪蛇绿岩的时空分布与演化特征,表明古亚洲洋东段索伦缝合带在晚石炭世存在洋内俯冲作用.     

西秦岭北缘达加勒埃达克质花岗岩地球化学特征及构造意义

西秦岭北部广泛分布中酸性岩体,时代多属于印支期和燕山期,并多具有埃达克岩的特点。本次研究分析了达加勒花岗岩的岩石学和岩石地球化学特征,发现该岩体主要是以花岗岩、二长花岗岩为主,属于高钾钙碱性系列; ACNK值在1. 1～1. 25之间,平均1. 17,属于过铝质;岩石富SiO2(67. 98%～74. 89%)和Al2O3(13. 27%～15. 50%),高Sr(773. 70×10-6～824. 30×10-6),低Yb(0. 48×10-6～1. 32×10-6)、Y(2. 79×10-6～14. 24×10-6),(La/Yb)N比值24. 39～45. 73,无负Eu异常(δEu=0. 57～1. 08),具有典型的埃达克岩地球化学特征。研究认为花岗岩浆起源于下地壳的部分熔融,源岩主要是变质杂砂岩,有少量的泥质岩,其形成时代可能为燕山早期。这与研究区印支—燕山期存在陆陆碰撞或者陆陆俯冲导致地壳加厚,加厚的下地壳发生部分熔融结果一致。     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.     

郯庐断裂南段研究进展与断裂性质讨论

据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。     

塘口水电站坝基岩体透水性和渗漏问题分析

塘口水电站大坝基础座落在断层和裂隙较发育的龟裂纹灰岩上,岩体完整性差、透水性强,多年运行后,大坝灌浆廊道和排水廊道出现多处集中性漏水,为确保大坝安全和电站正常发电,根据渗漏性质和成因,采用对灌浆廊道补充帷幕灌浆,对排水廊道进行固结+帷幕+回填灌浆。通过灌浆处理后,效果良好,表明灌浆工程有效的将导致坝基渗漏的上下游的裂隙通道封闭,并顺利的经受了随后的汛期洪水考验,大坝安全得到保障。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

Report of the restudy of the defined global stratotype of the base of the Silurian System

The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.     

Calculation of the Inverse of the Covariance

In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T ₃ = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.     

Artemia in the Salt Lakes of Russia:the Productivity of Populations,the Reserves of the Cysts and the Fisheries

正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the