甘肃靖远─景泰泥盆系湖相风暴岩及其古地理意义

甘肃靖远景泰一带泥盆系雪山组和沙流水组以河湖相碎屑岩为主 ,内发育典型的风暴沉积构造 (包括渠铸型、槽筑型、丘状交错层理和洼状交错层理、平等层理、块状层理和递变层理等 )。雪山组和沙流水组的风暴沉积主要包括 3种岩相类型 :A底部具渠铸型或槽筑型的块状层理和递变层理砂岩。 B具丘状或洼状交错层理及平行层理的砂岩。C具均质层理的粉砂岩、泥质岩。上述岩相 A,B,C分别代表风暴事件沉积中风暴流行作用 -风暴后的快速悬浮沉积 (事件沉积 ) ,它们组合成典型的风暴沉积序列。甘肃靖远一带晚加里东 -早海西期位于北祁连造山带北缘同造山盆地的构造背景下 ,泥盆纪雪山组 -沙流水组以河湖相沉积为主。泥盆纪湖相风暴岩的发现表明该区处于低纬度 (5°～ 2 0°)的风暴作用带。中、晚泥盆世北祁连造山带构造隆升渐弱 ,海拔不高 ,不足以阻隔风暴作用对山后湖盆的侵扰。因此在近海湖盆中形成风暴岩沉积。该沉积对于认识北祁连 -河西走廊泥盆纪的古地理、古气候及古构造具有重要意义     

贵州紫云地区上泥盆统风暴重力流沉积特征及地质意义

贵州紫云地区上泥盆统代化组以海相碳酸盐岩为主,该组地层发育多套重力流沉积及两套风暴岩的沉积,其中重力流沉积主要以多期块状杂基支撑的砾屑灰岩组成的碎屑流充填为特征,而风暴岩沉积特征主要包括侵蚀构造、洼状交错层理、递变层理及泄水构造等。通过研究发现,本区风暴重力流共发育3种沉积序列组合,这3种序列组合代表了较深水的古地理环境,这就证实了滇黔桂盆地在泥盆纪台地间槽盆环境的存在,其风暴岩的发现指示了研究区晚泥盆世应位于赤道附近的低纬度区域,气候温暖,水体清洁。     

Significance of pot and gutter casts in a Middle Triassic carbonate platform, Betic Cordillera, southern Spain

Pot casts and gutter casts are described for the first time in the lower part of the Majanillos Formation, a Middle Triassic carbonate unit located in the External Zones of the Betic Cordillera (southern Spain). Their identification, as well as their relation to tempestites, enables the better interpretation of the depositional environments and the shoreline-to-offshore facies transition on the Anisian muddy carbonate ramp of the southern Iberian Massif. The Majanillos Formation contains three members, which become progressively more marly towards the top. Well-preserved pot and gutter casts and thin intercalations of calcarenite, which are interpreted as tempestites, are abundant in the lowest member. Above the pot and gutter casts, thicker calcarenite beds, which locally contain hummocky cross-stratification, predominate. Bioturbated nodular limestones are prevalent at the top of the member. The remaining succession, which records a long-term Triassic transgressive cycle, consists mostly of fine-grained limestones deposited in very shallow-marine environments. Calcarenitic sediments only accumulated within potholes and gutters in the nearshore. They developed during storms when strong currents transported sediment to the outer shelf, where it was deposited as tempestite beds. Pot and gutter casts characterize sedimentation in the bypass zone. It is concluded that storm deposits provide important constraints for the interpretation of palaeobathymetry; it is proposed that gutter casts display a trend of increasing width/thickness ratios towards the outer shelf. The identification of these structures in marine successions elsewhere should prove useful in the interpretation of depositional environments.     

拉萨地块林周盆地下白垩统塔克那组：新特提斯洋活动陆缘伸展阶段沉积记录

拉萨地块林周盆地下白垩统塔克那组沉积于新特提斯洋壳向拉萨地块俯冲的弧后伸展环境，对重构该时期古地理格局、理解活动陆缘伸展构造对沉积的控制作用具有重要意义。基于野外露头描述和薄片观察，总结塔克那组岩石地层、岩石学和古生物特征，对比同期新特提斯被动陆缘阿拉伯板块Shuaiba组，讨论塔克那组沉积演化和活动陆缘沉积特征。塔克那组发育碎屑岩、硅质碎屑- 碳酸盐混积岩、碳酸盐岩三大类沉积岩十种岩石类型，纵向上划分为四个岩性段，是一个三级相对海平面变化旋回的沉积层系。塔一段砂岩—混积岩—灰岩岩性变化、沉积构造和生物类型均指示潮间- 潮下带潟湖环境；塔二段沉积于海平面快速上升期，主要为风暴浪基面之下厚层泥灰岩；塔三段在玛行西剖面首次识别出代表风暴浪基面之上的风暴成因生物富集层，往西南在甲绒东剖面相变为浅滩相生屑/鲕粒颗粒灰岩；塔四段沉积期海平面持续下降，海水逐渐退出盆地，沉积滨岸和泛滥平原环境的泥页岩夹粉砂岩。与阿拉伯板块同期生物种属对比表明，塔克那组沉积期，南拉萨地块林周盆地与新特提斯洋沟通性好。活动陆缘伸展背景下，具有基底快速差异沉降、陆源沉积物持续输入的特征，导致纵、横向相变快，混积岩发育，厚壳蛤、Lithocodium- Bacinella等浅海喜净水生物和深水浮游生物欠发育。     

甘肃天祝斜壕地区上奥陶统远源钙质风暴岩的发现

甘肃天祝斜壕地区上奥陶统斯家沟组灰泥岩薄互层段和斜壕组黑色页岩段中发育一种间隔性（数十厘米至数米）出现的薄层（数厘米至十几厘米）浅灰色─灰白色的泥─微晶灰岩。其内部往往发育丘状、波纹伏、卷曲优等层理，层面多具波状起伏，底面可见小型槽模、沟模等，并且预底发育属Ｃｒｕｚｉａｎａ－Ｚｏｏｐｈｙｃｏｓ混合相的遗迹化石。其成因是风暴作用形成的，属产于浅海陆架较深水地带的远源钙质风暴岩。     

A Study of Sedimentary Environment and Reservoir Quality of the Carboniferous Donghe Sandstonein the Tarim Basin

Very thick, fine-grained quartzose sandstone of the Lower Carboniferous (called the Donghe sandstone) was discovered in Donghe-1 well in the Tarim basin. Highly-productive commercial oil and gas flows were obtained when a well completion test was conducted. This important discovery proved that the quartzose sandstone is a prospecting target with good prospects. After that, other two paying oil and gas flows were found in the Lower Carboniferous in the Tazhong-4 and Tazhong-10 structures (Tazhong means central Tarim), equivalent to the Donghe sandstone. The Tazhong-4 structural oil field is the biggest oil field ever discovered. Therefore it is of guiding importance in oil and gas exploration to deepen the study of sedimentary and reservoir features and the sedimentary environment of the Donghe sandstone and to build a sedimentary model in order to understand the reservoir distribution pattern.     

新疆英吉沙南克孜勒陶组沉积特征及沉积相

英吉沙南阿克巴西麻扎尔一带的中泥盆统克孜勒陶组，下未见底，与上覆上泥盆统考库亚组之间呈整合接触．从剖面特征分析，自下而上可划分出海岸相及混积陆棚相(包括生物礁、风暴岩)，为一典型的进积沉积体系．各相段中沉移特征明显，沉积构造十分发育，特别是上部具有点礁性质的生物礁不仅礁核、礁翼清晰，而且定殖、拓殖、泛殖、统殖等4阶段特征明显．该剖面为研究滨浅海相沉积的良好剖面。     

鄂尔多斯盆地大牛地气田下二叠统下石盒子组盒2及盒3段风暴岩研究

首次提出在鄂尔多斯盆地大牛地气田下二叠统下石盒子组盒2及盒3段发育风暴岩。前人认为该区盒2及盒3段为一套河流相沉积体系,而风暴岩的发现证明还广泛发育一套湖泊沉积。鄂尔多斯盆地大牛地气田盒2及盒3段沉积时期,湖泊水面广阔,地形平缓,总体水体较浅,为浅水湖泊环境,易产生风暴回流。根据岩心观察和粒度分析资料,研究区内发育丰富的浅湖风暴岩沉积构造,主要有截切构造、渠模、丘状交错层理和冲刷面等典型的风暴成因构造。粒度概率累积曲线也反映出重力流和牵引流兼有的复杂的水动力机制。研究区风暴岩理想的沉积单元从下至上可概括为“似鲍马序列”,即：A、递变层理和块状层理段;B、平行层理段;C、丘状交错层理和洼状交错层理段;D、波状层理段;E、泥岩段。风暴岩是湖泊发育的典型标志,所以风暴岩的提出对确定研究区的沉积相类型增加了新的认识,并且对下石盒子组的古地理恢复具有重要意义。     

青岛灵山岛下白垩统湖泊风暴沉积与风暴作用

灵山岛背来石剖面发育了非常典型的湖泊风暴岩和风暴作用。非常典型的丘、洼状构造发育在火山岩底部的砂页岩中。丘状构造呈典型的丘状,规模不一,小者高数厘米,宽数十厘米;大者高2. 4m,宽12. 48m;具有典型的二元结构：底部为灰色或浅灰色的砂砾岩或砂岩;顶部为深灰色 黑色泥岩、页岩或薄层砂岩互层。砂砾岩分选磨圆均很差,砾石主要为片麻岩,直径多在数毫米到3~4cm,呈悬浮式胶结。砾岩底部为凹凸不平的侵蚀面,砾岩向丘状构造两翼变薄甚至尖灭,与下部侵蚀面呈典型的角度交切。丘状构造的上部的细粒层有四个要素：①上凸形态;②丘状交错层理;③下细上粗的二元结构;④底部具侵蚀面。洼状构造也具有典型的洼状,规模也不一,小者高数厘米,宽十余厘米;大者高2. 4m,宽18. 70m,具有下细上粗的（反)二元结构,但底部多为深灰 灰黑色、甚至黑色的泥岩、页岩或夹薄层砂岩,上部多为砂岩、砂砾岩或砾岩。完整的洼状构造也有四个要素：①下凹形态;②或有洼状交错层理;③下细上粗的（反)二元结构;④底部具侵蚀面。丘状构造与洼状构造在空间上相邻共生,但不是同时形成的,一个连续的完整序列是丘状构造形成在先,洼状构造形成在后,其间由一个粒度较细的薄层分隔开（风暴最高水位时的“静”水沉积)。基于实验和丘洼构造参数计算了风暴浪的相关参数。     

峡东地区埃迪卡拉系灯影组风暴岩的发现 及其环境意义

本文首次报道了峡东地区埃迪卡拉系灯影组石板滩段地层中的风暴岩。通过详细的剖面观察、测制和室内研究,识别出石板滩段典型的风暴沉积标志,包括各种丘状交错层理、粒序层理、冲刷 充填构造、平行层理及变形层理等。结合各类风暴沉积标志在剖面上的组合关系将研究区风暴岩划分出4个风暴沉积序列类型：其中类型Ⅰ为风暴流成因的滞留沉积与底面的冲刷面、丘状层理、波状层理、水平层理的组合,属形成于正常浪基面附近的近原地风暴岩; 类型Ⅱ为具颗粒流性质的块状内碎屑灰岩与丘状交错层理的组合,常见变形层理,形成于斜坡上部;类型Ⅲ为以渠模、丘状交错层理与水平层理的频繁叠加为特征,出现在风暴浪基面与正常浪基面之间;类型Ⅳ为具粒序层理的砂 砾屑浊积灰岩,形成于风暴浪基面以下,划归为风暴成因的远源浊流沉积。研究区风暴岩的特征表明：风暴层蕴含了强烈的气候信息,风暴频发是灯影期气候转型的重要响应;该时期构造相对活跃、海底地形复杂化是风暴沉积形成的原因之一;研究风暴岩的特征对等时地层对比研究也具有重要意义。