卡塔尔鲁卜哈利盆地古生界生储盖组合特征

卡塔尔鲁卜哈利盆地古生界碎屑岩是油气勘探的新领域,在区域地质研究的基础上,利用石油地质学、储层地质学等理论对古生界的生储盖组合进行研究,并重点分析了盖层发育特征.研究结果表明,卡塔尔鲁卜哈利盆地古生界发育良好的生储盖组合,志留系Qusaiba热页岩是主力烃源岩,泥盆系Jauf组滨岸相砂岩和二叠系Unayzah组河流—三角洲相砂岩是主要储层,二叠系Khuff组膏岩及底部的海侵泥岩为区域盖层,同时还发育多套局部盖层.盖层的封盖能力是古生界油气勘探的主要风险之一,区域盖层横向分布稳定,且含膏岩,封盖性好,但局部盖层厚度较薄并且泥岩质不纯,夹薄层白云质泥岩和少量粉砂岩,对封盖能力影响较大,盖层风险不容忽视.     

三塘湖盆地卡拉岗组火山岩储层成岩作用*

通过岩芯宏观观察、显微镜下铸体薄片精细观察,讨论了三塘湖盆地卡拉岗组火山岩储层的岩性岩相特征、储集空间发育特征及成岩作用特征,分析了成岩作用类型与孔洞形成机制。结合火山岩岩石化学分析,并依据火山岩成岩变化特征和过程与火山岩储层储集空间形成的相互关系,将三塘湖盆地石炭系火山岩成岩作用归纳为9种类型、4个成岩期或阶段。冷凝结晶固结成岩作用期和埋藏-热液成岩作用期沸石类杏仁体和充填缝是风化壳储层形成的关键物质基础,早期和晚期表生成岩作用期在各类缝的沟通系统内易溶组分的强烈溶蚀作用是风化壳储层形成的关键作用,并由此形成喷发间期风化壳储层和区域构造抬升剥蚀风化壳储层两类风化壳储层。     

Lasing on pyroclastic rocks: A case study of <Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar dating on Moshishan Group,eastern Zhejiang Province

It is difficult to date pyroclastic rocks, for almost all the dating methods, due to the multiple sources during their formation. ^40Ar/^39gAr incremental heating results on groundmass selected from the samples show that the age spectra are meaningless geologically. However, singe crystal total fusions of CO2 lasing on the sanidine separates could yield rational 4^40Ar/^39Ar results and distinguish their sources in this study. Timing on three formations of the Moshishan Group, after avoiding the exotic and altered grains by lasing on the single sanidine separate, was reported in this paper. The lowermost portion of the Chawan Formation gives an age of 113.7±0.3 Ma; the lower part of the Xishantou Formation was formed 116.4±0.4 Ma ago and the bottom of the Gaowu Formation took its shape at 118.4±0.4 Ma. These new ages are much younger than the previous ones, suggesting that these thick volcanic formations had been formed in very short durations.     

LA-ICP-MS dating of Zhangjiakou Formation volcanic rocks in the Zhangjiakou region and its geological significance

The geological cross section of the Zhangjiakou Formation is originally established in the Zhangjiakou region. From the dating of four samples from typical cross sections of the Zhangjiakou Formation in the Zhangjiakou region, the age range is found to be mainly from 143.0 ± 3.7 Myr to 136.1 ± 1.4 Myr, which almost equals the sum of the age range of the Zhangjiakou Formation （136-135 Myr） and that of the Tuchengzi Formation （143-136 Myr） in the Luanping region, and the Zhangjiakou and Tuchengzi Formations in Zhang- jiakou-Luanping of North Hebei are found to be conformable. The evidence above indicates that the Zhangjiakou and Tuchengzi Formations, which are distributed in Zhangjiakou-Luanping, were formed under the same geological setting. Volcanic activity was earlier and longer （143-136 Myr） in the western region （Zhangjiakou） than that in the eastern region （Luanping）. The ＂Zhangjiakou Formation＂ in Chengde and Pingquan formed in the period in which the Yixian Formation in West Liaoning formed, so should be renamed the Yixian Formation.     

Evidence for metasomatic mantle carbonatitic magma extrusion in Mesoproterozoic ore-hosting dolomite rocks in the middle Kunyang rift, central Yunnan, China

The Kunyang rift lying on the western margin of the Yangtze platform is a rare Precambrian Fe-Cu mineralization zone. Wuding- Lufeng basin that is an important part of the zone is located on the west edge in the middle of the rift. The most important ore-hosting rocks are Mesoproterozoic dolomite rocks in the basin controlled by a ring fracture system, which is a fundamental structure of the basin. Plenty of silicate minerals and acicular apatite, feldspar phenocrysts and small vesicular, flown line and flown plane structures, melt inclusion and high temperature fluid inclusion found in most ore-hosting dolomites suggest that this kind of rocks could not be sedimentary dolomite, marble or hydrothermal carbonate rocks. The Zr/Hf and Nb/Ta values of the rocks are identical with those of associated mantle-derived rocks, and vary widely. For the monomineral dolomite, δ^18OSMOW‰=＋5.99 to ＋18.4 and δ^13CPDB‰ = -3.01 to ＋0.94, which fall within the range for all carbonatitic volcanic rocks of the world. As for the accessory minerals, the values of δ^18OSMOW‰ of magnetite （=＋3.47 to ＋5.99‰） are close to that of the mantle （〈5.7%）, and the δ^34S‰ values of sulfides （-5.09 to ＋5.78, averaging ＋1.50） are close to that of meteorite. For all the ore-bearing dolomite rocks, εNd = ＋0.19 to ＋2.27, and the calculated Isr=0.699143, while for the associated mantle-derived rocks, εnd = ＋3.18 to ＋3.72. All the data suggest that the mineral assemblage is not only igneous but also of metasomatic mantle origin. And the presence of acicular apatite indicates that the rocks were formed by magma rapidly cooling. And the phenocryst texture and vesicular, flown and ropy and pyroclastic structures suggest that the igneous rocks were extrusive. Therefore, the ore-bearing dolomite rocks are carbonatitic volcanic rocks. This conclusion implies that most iron and copper ore deposits hosted in the dolomite rocks should be of the carbonatite type.     

大庆徐家围子断陷火山岩储集性控制因素分析

为预测大庆徐家围子断陷营城组火山岩储层有利相带的分布,对火山岩储集性的控制因素进行了分析。岩芯和薄片观察表明,原生孔隙是火山岩储集空间形成的基础,次生孔隙是储集空间的重要组成部分。通过对火山岩孔隙类型的统计,结合对岩芯物性的对比分析,发现控制火山岩储集性的主要因素有火山岩岩相、构造裂缝和酸性流体的溶蚀作用等。不整合面下方火山机构地貌突出且火山岩溶蚀强烈的部位应该成为今后重点勘探的区域。     

川西坳陷孝-新-合地区须家河组烃源岩地化特征对比及评价

川西坳陷孝泉-新场-合兴场地区须家河组发育大套优质烃源岩．通过一系列有机地球化学分析方法对其各个层段的有机质丰度、有机质类型和有机质成熟度进行了研究对比,认为该区须家河组烃源岩除小塘子-马鞍塘组和须三、须五段主要的烃源岩段较为发育外,须二、须四段也发育相对较好的烃源岩,这些储层段中发育的烃源岩构成了成藏子系统发育的基础;烃源岩有机质丰度高,有机质类型主要为Ⅲ型、部分为Ⅱ,型,有机质成熟度高,且随深度增大各项反映成熟度的指标值均逐渐增大;有机碳含量和成熟度的平面分布除丰谷地区须三段相对最高外,其他层段均表现为西高东低的特征。     

煤巷大厚度泥岩顶板围岩裂隙演化规律数值试验研究

运用数值试验系统,研究了煤巷大厚度泥岩顶板围岩裂隙萌生-扩展-贯通-破坏的演化规律。根据围岩裂隙的分布和演化,结合地质力学与环境条件,揭示出大厚度泥岩顶板垮落是由于煤帮上方的剪张裂隙及顶板上方的水平裂隙所形成的裂隙拱造成的,提出大厚度泥岩顶板煤巷支护的三个主要特点:及时封闭围岩、加大锚杆支护系统刚度、锚杆(索)沿裂隙方向斜向布置。研究结果有利于了解巷道围岩内部破裂的产生和发展规律,为巷道锚固方案的选择和锚固参数的优化提供了依据,可为类似条件矿井的支护提供理论依据与应用性指导。     

贵州乌当地区泥盆系乌当组下部粘土岩成因的初步研究

于贵州乌当地区泥盆系乌当组下部发现了3层粘土岩,运用X射线衍射（XRD）、湿化学法和电感耦合等离子体质谱（ICP—MS）等分析方法分别对其矿物组成、主量元素及微量元素含量进行分析。结果显示这3层粘土岩中的粘土矿物主要为蒙脱石和伊利石,同时含少量高岭石。粘土岩的K2O含量范围为5．60％～7．77％,平均值为6．92％,...     

西藏阿翁错盆地古近系牛堡组烃源岩地球化学特征

在西藏阿翁错盆地古近系牛堡组实测剖面的基础上,对烃源岩有机质丰度、有机质类型、有机质成熟度等方面进行研究,结果表明牛堡组烃源岩有机质丰度中等偏低,泥页岩和泥晶灰岩有机碳平均质量分数分别为0.26%和O.15%,泥页岩表现出较差烃源岩特征,泥晶灰岩则表现为中等烃源岩特征.泥页岩有机质类型以Ⅱ1型和Ⅱ2型为主,泥晶灰岩有机...