雪峰山西侧地区下寒武统牛蹄塘组烃源岩特征 与油气地质意义

通过对雪峰山西侧地区下寒武统牛蹄塘组烃源岩的系统观测、采样和有机地球化学研究,总结了烃源岩的分布规律、有机质母质类型、烃源岩形成与沉积环境的关系、有机质成熟度等。牛蹄塘组烃源岩具有高有机碳、低氯仿沥青“A”、低生烃潜能的特征,有利烃源岩主要分布在黔北遵义、黔东天柱—城步、渝东南—湘西酉阳—麻阳一带及鄂西咸丰—张家界一带。干酪根镜下鉴定表明,有机质以腐泥组为主(75%~93%),饱和烃/芳烃占0.84%~27%,平均5.77%,牛蹄塘组烃源岩有机质类型为Ⅰ型。干酪根δ13Corg较轻,为-34.99‰~-25.36‰,平均-31.80‰,显示沉积母质以浮游生物及海洋性自养菌为主,部分样品有机质来源以藻类为主,结合Pr/ph分析,烃源岩主要形成于缺氧且通常是超盐度的环境中。沥青反射率为2.23%~4.32%,平均3.45%,等效镜质体反射率为1.84%~3.23%,平均2.43%,表明大部分样品已达到过成熟阶段。     

中国华南陡山沱组烃源岩的形成机制与分布预测

震旦系(埃迪卡拉系)陡山沱组是成冰系(南华系)极端冰期事件结束后首次沉积的泥岩和碳酸盐岩地层,大规模的海侵活动导致在全球广泛发育富有机质黑色页岩,可能是未来深层油气和页岩气勘探的重要烃源岩层.中国华南陡山沱组烃源岩分布广泛,由于受古构造格局、沉积相带等因素影响,烃源岩非均质性强、平面上分布差异大.本文在前人研究基础上,结合3个剖面的有机地球化学、古生物学和沉积地球化学等分析,对比华南10个典型剖面,分别对陡二段和陡四段烃源岩的沉积环境开展分析对比,认为陡二段烃源岩形成于海侵背景下的贫氧环境,陡四段烃源岩形成于海退背景下的缺氧滞留环境;多细胞藻类和疑源类是主要有机质母源.不同相带对比研究表明,台地相烃源岩主要发育在陡四段(TOC平均值为3.61％),斜坡相烃源岩在陡二段(TOC均值为2.20％)和陡四段均发育(TOC平均值为3.66％).烃源岩质量和厚度明显受控于沉积环境和古裂陷地质结构等.结合露头和钻井资料,对华南陡山沱组烃源岩分布及厚度开展预测和编图,提出了优质烃源岩分布的有利区域,为深层油气勘探和页岩气富集区预测提供了依据.     

富有机质的黑色页岩和油页岩的有机岩石学特征与生、排烃意义

用近代有机岩石学与有机地球化学分析相结合的方法，对比研究了我国四川盆地等下古生界富有机质沉积的海相黑色页岩,和渤海湾盆地下第三系湖相油页岩的显微有机组成特征与热演化生烃、排烃作用的关系。观测分析结果表明:黑色页岩热演化程度很高，目前热解烃含量很低，但残余有机碳含量达1％～3％，黑色页岩中保存了早期生油阶段由无定型有机质生油作用转化而形成的微粒体有机质，和未排出的石油演变而来的残余沥青，表明其为原始生烃性能很好的烃源岩。根据黑色页岩中微粒体和残余沥青的含量，可用来了解已生—排烃量和再沉降埋深过程中古油藏储层沥青、微粒体和残余沥青再生气对古生界碳酸盐气藏的贡献。富有机质沉积的下第三系湖相油页岩热演化程度不高，游离烃（S1为0.2～1.4 mg/g）和热解烃（S2为8～44 mg/g），有机碳含量达2.4％～8％，是生油性能很好的烃源岩，油页岩中不仅存在强荧光的藻和无定型有机质，而且油页岩的纹层中广泛存在富有机质的荧光沥青，反映了有利于排烃运移的信息，表明是本区生油贡献最大的烃源岩。富有机质黑色页岩和油页岩的沉积结构构造特征、有机质的赋存形式、热演化中变化过程的对比观察结果表明:其生烃、排烃作用既有很多相似性，又有一定差别。     

当阳复向斜上组合生烃潜力及其含油气系统

当阳复向斜上组合存在志留系、二叠系及下三叠统三套烃源层，以碳酸盐岩及泥质岩为主。以志留系底部厚约５０ｍ的黑色页岩生油条件最好，在王家湾剖面有机碳含量平均达３．７７％；次为二叠系碳酸盐岩，全区有机碳平均含量为０．３６％。干酪根碳同位素特征和扫描电特征均显示该区烃源岩母质类型主要为Ⅰ型和Ⅱ型。有机质热演化程度普遍较高，应以天然气勘探为主。利用“二维源岩评价系统”软件进行了盆地模拟，三套烃源层的累积生烃     

西藏南羌塘坳陷泥质烃源岩评价及有利生烃区预测

羌塘盆地是中国特提斯域面积最大、最具有含油气远景的沉积盆地,盆地内沉积有多套泥质烃源岩层,其中上三叠统土门格拉组、中—下侏罗统曲色—色哇组以及上侏罗统安多组三个层段生烃潜力巨大。本文在充分收集前人资料基础上,通过有机地球化学分析对南羌塘坳陷中生界上述三套泥质烃源岩层进行了综合评价研究,并对它们的生烃有利区进行了预测,探讨了优质烃源岩形成的主控因素。结果显示土门格拉组烃源岩有机质丰度中等偏低,有机质类型主为Ⅱ型,热演化程度较高,整体为差—中等生油岩,主力生烃坳陷位于分布在双湖多普勒乃—查郎拉和安多达卓玛—土门一带;曲色—色哇组有机质类型较好（Ⅱ1型）,但有机质丰度偏低,且处于高成熟—过成熟阶段,属差生油岩,有利生烃区主要位于西部昂达尔错、中部扎曲乡和东部达玛尔地区,同时在双湖毕洛错地区发育一个相对局限的优质烃源岩区;安多组有机质丰度高,且有机质类型好（Ⅱ1型）,处于生油高峰的成熟阶段,为好生油岩,但分布局限,主要位于安多114道班地区。沉积环境是南羌塘坳陷优质泥质烃源岩形成的主控因素：土门格拉组时期,温暖、潮湿的气候条件以及海—陆过渡环境相对较高的沉积速率,为该套优质泥质烃源岩的形成提供了条件;对于曲色—色哇组,广海边缘外陆棚体系不利于有机碳的沉积和埋藏,而相对局限的障壁—潟湖沉积环境则是优质烃源岩的有利形成区;上侏罗统安多组深水台沟相低能、静水的还原环境,以及浅水区稳定的有机质供给促进了该区富有机质黑色岩系的形成。这些研究对进一步明确羌塘盆地主力烃源岩特征与分布及下一步油气勘探具有重要参考价值。     

利用偏光显微镜反射光系统观察黑色生油岩电子探针薄片中的生烃母质特征

鄂尔多斯盆地上三叠统延长组长7油层组的黑色泥岩、油页岩等黑色生油岩薄片中的生烃母质,因黑色石油、沥青等黑色有机质的覆盖或不透明,导致其在偏光显微镜透射光系统下观察常局部或整体呈现为黑色。因此,建立一种黑色生油岩薄片中生烃母质有效观察的方法,对致密油、页岩油的生烃研究具有重要的理论和实际意义。本文提出了一种利用电子探针薄片和偏光显微镜的反射光系统观察黑色生油岩中生烃母质特征的方法。该方法能够克服黑色生油岩薄片中生烃母质因被黑色有机质覆盖或不透明,而在偏光显微镜的透射光系统下局部或整体呈黑色的弊端,能够对生烃母质的大小、形态、结构、分布和物质成分等特征进行整体且清晰的观察。实践表明,本文提出的利用偏光显微镜反射光系统观察黑色生油岩电子探针薄片中生烃母质特征的方法,简单有效,易在致密油、页岩油的生烃研究领域推广使用。     

地质条件下湖相烃源岩生排烃效率与模式

烃源岩排烃研究是油气地球化学研究中最薄弱的环节,而排烃效率又是准确评价常规油气与非常规页岩油气资源的关键参数。目前对于烃源岩排烃效率的认识差异很大,尚未建立完整的各种类型有机质湖相烃源岩在地质条件下生排烃效率与模式。本文以中国渤海湾、松辽等4个大型湖相含油气盆地以及酒泉青西凹陷、泌阳凹陷等9个中小型湖相富油盆地/断陷为对象,通过15000余个湖相烃源岩样品在自然热演化过程中热解生烃潜力指数的变化研究,揭示了湖相烃源岩在地质条件下的生排烃特征,构建了湖相烃源岩在地质条件下的生排烃效率与模型。无论是大型湖相沉积盆地还是中小型断陷盆地,甚至是盐湖相沉积盆地,烃源岩生排烃特征基本一致。随着成熟度的增高,湖相烃源岩排烃效率逐渐增高,在低成熟阶段排烃效率较低,在成熟与高成熟阶段具有高或很高的排烃效率。Ⅰ型、Ⅱ型有机质类型烃源岩排烃模式相似,相对排烃效率在低成熟阶段小于45%,成熟生油高峰时达85%~90%,至生油窗下限时达90%以上;累积排烃效率在低成熟阶段小于10%,生油高峰时达50%~60%,生油窗下限时达75%~85%,主要的排烃阶段在镜质组反射率0.7%~1.2%之间,生油窗阶段生成并排出了绝大部分烃类。湖相Ⅲ型有机质烃源岩排烃效率明显低于Ⅰ、Ⅱ型有机质烃源岩,生油窗阶段累积排烃效率仅为50%左右,主要生排烃阶段在镜质组反射率0.8%~2.0%之间。控制湖相烃源岩排烃量和排烃效率的主要因素是有机质丰度、类型和成熟度,而盆地类型、断裂发育程度、烃源岩沉积环境、相邻输导层孔渗条件等因素均不影响烃源岩排烃与排烃效率。     

四川盆地震旦系陡山沱组烃源岩地球化学特征与有机质富集机制

深层古老层系在油气勘探中的重要性正越来越受到重视,四川盆地震旦系陡山沱组是中国南方这一领域的潜在烃源岩层系,但过去因关注少而研究程度低。为加深对其理解,文章以样品条件较好的四川盆地东北缘城口明月乡剖面为例,采用岩石学、主、微量及稀土元素等综合分析的方法,系统探讨了陡山沱组泥页岩的地球化学特征和有机质富集机制。结果表明,陡山沱组发育了一套富有机质的泥页岩,主体沉积于次氧化—还原水体环境,显著的Eu 正异常表明沉积时受热液活动影响明显。烃源岩有机质富集显著受控于沉积环境,同时由于沉积时整体处于较低的沉积速率,使得自下而上随沉积速率增大,有机质逐渐富集。此外,热液活动促进了有机质富集。陡山沱组具有资源潜力,但非均质性发育,可能与冰期—间冰期的海平面升降有关。     

准噶尔盆地吉木萨尔凹陷二叠系芦草沟组优质烃源岩特征及其生烃机制研究

准噶尔盆地吉木萨尔凹陷芦草沟组发育凝灰物质,凝灰物质在页岩油形成过程中具有的重要作用,其发育层段也是页岩油分布最好的层段,凝灰物质的分布及与有机质生烃关系的研究对于吉木萨尔页岩油油气成藏规律的认识和深入研究具有重要意义。本文通过对吉木萨尔芦草沟组烃源岩精细评价及沉积环境分析,与烃类活动具有成因关系的成岩矿物解剖,探讨了形成优质页岩油源岩的控制因素和生烃机制。烃源岩定性评价结果表明,泥晶白云岩是吉木萨尔凹陷芦草沟组主要生油岩,烃源岩有机质丰度高,有机质类型以Ⅰ型和Ⅱ_1型为主,生烃潜力较好,R_o值分布在0.6%～1.1%,C_(29)αααS/(S+R)值范围在0.3～0.5,显示烃源岩处于成熟阶段;芦草沟组烃源岩中规则甾烷C_(27)、C_(28)、C_(29)分布为C_(27)C_(28)C_(29),结合微观分析认为其生烃母质以藻类和超微生物为主,Ts/Tm值较低,分布在0.05～0.18,具有高含量的β-胡萝卜烷,反映其母质处于半咸水的弱氧化—弱还原的沉积环境之中,而这一时期火山活动提供的凝灰物质对烃源岩的生烃环境及热演化进程都有重要影响,热演化突然增大的层段与有机质成熟的"甜点段"的分布深度一致。凝灰物质与含超微生物及藻类的泥晶白云岩的混合是导致生烃和早期生烃的重要原因,两者混合的不均一性导致页岩油分布与成熟度的不均匀性。     

扬子板块伊迪卡拉(震旦)纪多细胞生物的发展与烃源岩的形成

生物的生产量以及被保存的沉积有机质是烃源岩形成的重要条件。多细胞生物出现并广泛地生活于扬子地区伊迪卡拉纪陡山沱期晚期的浅海中,生物之间相互依赖和共存的多层次化和复杂化生态系统的建立,使陡山沱期成为扬子地区生命演化和发展重要时期。陡山沱期的黑色泥(页)岩在沉积时为富含水份的粥性沉积物,同时当时海洋中的氧化-还原界面较浅,生物遗体可迅速地被沉积物所覆盖而形成烃源岩。伊迪卡拉纪陡山沱期是化学、气候和环境变化的剧烈时期,也是扬子地区生命演化、有机质生产力发展和烃源岩形成的一个重要时期。     

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.     

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.     

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″.     

The Tendencies of the Development of the Mineral-Resources Sector at the Turn of the Century

Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.     

Causes of the famine among the rural population of the Sahelian zone of the Sudan

Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators.     

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。     

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。     

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.