川东北元坝地区长兴期-飞仙关期碳酸盐岩台地沉积体系及演化

四川盆地东北部元坝地区二叠纪-三叠纪沉积环境主要与北部广旺海槽形成与关闭、米仓山与大巴山隆起及二叠纪峨眉山玄武岩喷发有关.通过野外露头、三维地震数据、钻井资料的综合研究,认为长兴组-飞仙关组沉积为碳酸盐台地沉积体系,可进一步划分为台地蒸发岩、局限台地、开阔台地、台地边缘生物礁滩和台地边缘斜坡5个相带.长兴期沿台地边缘发育了台地边缘礁滩;飞一段早期相对平静,沉积末期广旺海槽全部关闭;飞二段至飞三段早期主要为开阔台地沉积;飞三段晚期-飞四段演变为局限台地-台地蒸发岩相.飞二段浅滩与长兴期礁滩大致处于相同位置,未发生侧向迁移;飞三段台内浅滩的发育有明显的侧向迁移和垂向叠置的特征;从西南向东北方向,飞仙关组早期台地沉积区向陆棚沉积区迁移.     

新疆三塘湖盆地烃源岩特征

新疆三塘湖盆地主要有三套烃源岩:中生界上三叠统和中下侏罗统煤系烃源岩、古生界上二叠统湖相低熟烃源岩和古生界下二叠统和石炭系湖相成熟烃源岩.烃源岩在马朗凹陷、条湖凹陷和汉水泉凹陷均有分布,岩性主要为暗色泥岩、煤和碳质泥岩.最有利的烃源岩为马朗凹陷中有机质丰度高、类型好、油气生成量大且碳酸盐岩含量高的上二叠统芦草沟组烃源岩.     

Discovery of marine fossils in the upper part of the Permian Linxi Formation in Lopingian, Xingmeng area, China

Two important geological issues have a long history of debate in the Xingmeng area. The first concerns the final closure of the North China plate, Siberia plate and several intermediate massifs in the area, and the other con- cerns the folding and lifting of the Xingmeng Trough. Dis- agreements arise because of issues involving the tectonic- palaeogeographical environment of the Upper Permian deposits of the Linxi Formation. The Linxi Formation （Upper Permian） is generally considered to be either an exclusively continental deposit or separated into marine- terrigenous facies deposited during the Lower to Middle Linxi Period and continental deposits in the Upper Linxi Period. However, in this study, large numbers of bryozoan and sponge spicule fossils were discovered for this first time in the thick limestone layers and lenses of the upper part of the Linxi Formation found in the Guandi section of Linxi county in eastern Inner Mongolia. At the same time, abun- dant bryozoan fossils were also found in sedimentary tuff slices that were collected from the upper part of the Tao- huayingzi Formation from the Taohuayingzi section in Ar Horqin Banner, and abundant small connecting body crinoid stem fossils were found in the dark shale of the Yangjiagou Formation from the Yangjiagou section of Jiutai county, Jilin Province. These marine fossils provide the first evidence that the Xingmeng area was still a marine or mainly marine environment at the end of the late Permian. This not only provides conclusive evidence for the recognition of the above two major geological issues but also promotes chan- ges in the approach towards research, exploration and development of oil and gas, shale gas （oil）, and other mineral resources that are preserved in the late Permian layers of the Northeast-Xingmeng area.     

Advance in the study of the Lower Triassic conodonts at Meishan Section, Changxing, Zhejiang Province

Meishan Section in Changxing County of Zhejiang Province is one of the four candidates of the global stratotype section and point (GSSP) of the Permian and Triassic boundary (PTB), and currently the conodonts have been widely accepted as the index fossils to define the Permian and Triassic boundary. The previous studies on the Lower Triassic conodonts at Meishan Section are summarized and the recent discovery of the Lower Triassic conodonts there is reported. The recognized data from the section indicate that Meishan is the best selection of the GSSP of PTB.     

云南澜沧老厂矿区石炭系划分及原中上石炭统碳酸盐岩时代归属探讨

参照目前的石炭纪和二叠纪地层划分方案,笔者将云南澜沧老厂矿区石炭系与滇西凤庆平掌剖面石炭系进行对比,认为老厂矿区只存在相当于平掌组下段的地层;根据在矿区原中上石炭统"C2 3"碳酸盐岩中所采到的化石面貌显示,该套碳酸盐岩应该属于早二叠世紫松期的沉积,即为下二叠统鱼塘寨组的上段,因而矿区平掌组上段的地层及上石炭统缺失.并重新厘定了老厂矿区的地层层序.     

四川盆地页岩气藏和连续型-非连续型气藏基本特征

四川盆地是一个多旋回叠合盆地,发育了两套海相优质烃源岩(下寒武统牛蹄塘组页岩,下志留统龙马溪组页岩),其有机质成熟度高(R_o=1.5%～6%),绝大多数地区普遍不利于页岩气藏的形成;另发育两套海陆过渡相(上二叠统龙潭组和上三叠统须家河组)优质烃源岩,其成熟度相对较低(R_o=0.7%～3%),在川西南-川南地区具有较有利的页岩气勘探前景.四川盆地页岩烃源岩排烃效率高, 为大规模油气藏提供了烃源;多存在晚期快速隆升调整过程, 为吸附气的解吸创造了条件.页岩气藏经历了早期地质条件优越、生物气高效成藏,中期深埋地腹、原油裂解气快速成藏,晚期快速隆升、脱溶气和解吸气调整成藏等过程.四川叠合盆地油气藏具有多样性特征, 发育了从非连续型到连续型完整序列的油气藏类型.典型的非连续型气藏主要是指构造圈闭(以及部分构造-岩性圈闭)气藏,其圈闭相对独立,非连续分布, 储集空间类型以孔隙型为主.震旦系威远气田、川东石炭系气田群及川东北下三叠统飞仙关组气藏群等具有相对典型的非连续型气藏特征.非连续型-连续型过渡气藏介于连续型气藏与非连续型气藏之间,呈分散状或连续状分布, 圈闭类型多以复合圈闭为主,可发育有裂缝圈闭(川东南二叠系阳新统气藏)及岩性圈闭(上三叠统须家河组气藏).储集空间以裂缝型或次生溶孔为主,非均质性强,普遍存在异常高压.四川盆地连续型气藏应以页岩气藏为主, 但现今未有成功勘探开发页岩气藏的实例.四川叠合盆地具有多旋回构造-沉积演化、优质烃源岩分布的区域性、储层的非均质性和天然气的活动性,及油气成藏经历了生物气、吸附气、裂解气、脱溶气和解吸气演替等多样性特征.因此,四川盆地的油气勘探和研究应形成常规与非常规、连续型与非连续型、原生与次生油气藏的立体勘探和研究局面, 尤其应加强非连续型-连续型过渡油气藏特征、形成机理和分布规律的研究.     

福建二叠纪介形类两新属

报道产自福建二叠纪的化石介形类两新属．Ｄａｔｉａｎｉａ　ｇｅｎ．ｎｏｖ，产自大田崆峒山晚二叠世长兴组上部，其共生化石主要有丰富的介形类、蜒、非蜒有孔虫和牙形刺．Ｈｅｔｅｒｏｂａｉｒ　ｄｉａ ｇｅｎ．ｎｏｖ．产自大田广平早二叠世栖霞组近中部．其共生化石主要有极丰富的介形类和非蜓有孔虫．根据它们的构造特征和壳面装饰特点，分别将Ｄａｔｉａｎｉａ　ｇｅｎ．ｎｏｖ．和Ｈｅｔｅｒｏｂａｉｒｄｉａ　ｇｅｎ．ｎｏｖ．归入Ａｒｃｙｚｏｉｄａｅ科．结合其共生化石内容和岩性特征，两新属应营正常浅海底栖生活方式．     

四川马角坝地区飞仙关组的双壳类动物群

文章简述了四川江油马角坝地区下三叠统飞仙关组中的双壳类化石组合特征，描述了１新种（Ｃｌａｒａｉａｊｉａｎｇｙｏｕｅｎｓｉｓ）和１新亚种（Ｃｌａｒａｉａｓｏｎｇｐａｎｅｎｓｉｓｍａｇｎｕｓ），划分出两个双壳类化石带（Ｐｓｅｕ－ｄｏｃｌａｒａｉａｗａｎｇｉ带和Ｅｕｍｏｒｐｈｏｔｉｓｍｕｌｔｉｆｏｒｍｉｓ－Ｃｌａｒａｉａａｕｒｉｔａ－Ｃｌａｒａｉａｓｔａｃｈｅｉ带），刊出了主要化石图版     

四川盆地南部嘉陵江组烃源研究

四川盆地南部地区嘉陵江组中具有较大天然气储量的气井在天然气组分上与储量较小的微气井有明显差异,前者天然气以高成熟的甲烷为主.烃类碳同位素特征证明天然气来源于深层二叠系高熟-过熟的烃源岩.地球化学指标反映出嘉陵江组基本不具备生成大量烃类的条件.作者将向下断达二叠系或更深、向上断达嘉陵江组的断层称为嘉陵江组气藏的"烃源断层".烃源断层为二叠系或更深层烃源岩中的天然气向嘉陵江组储层中运移提供了通道,是嘉陵江组天然气富集的关键要素之一.     

北祁连东段天祝冷龙岭一带三叠纪地层

近年来的调查研究表明，分布于北祁连东段天祝冷龙岭一带的叠系可划分为上三叠统和中三叠统两部分。前者含较丰富的我国北方晚三叠世Ｄ－Ｂ植物群化石，与甘肃靖远晚三叠世南营儿群最接近，同属温湿气候条件下的河流相至湖泊沼泽相含煤碎屑沉积。后者化石少，但能显示出较老的中三叠世面貌，与白银丁家窑组一致，建议用南营儿群和丁家窑组分别代表本区的晚三叠世和中三叠世地层。