中上扬子地区上二叠统长兴阶岩石主要为碳酸盐岩，其次为碎屑岩和硅岩，少量煤和火山碎屑岩；其岩相可归纳为碎屑岩型、碎屑岩—石灰岩型、石灰岩型、石灰岩—硅岩型、硅岩—碎屑岩型等五种类型；其生物化石具4个基本生态类型，可划分为5种化石组合。以沉积岩石学理论为指导，以单因素分析多因素综合作图法为方法论，选取了厚度、海相岩含量、浅水碳酸盐岩含量、具灰泥基质的生屑含量、具亮晶胶结的生屑含量、生物礁的分布、薄层硅岩含量和深水沉积岩含量等单因素，对中上扬子地区晚二叠世长兴期岩相古地理进行研究与编图。共编制单因素图件8幅，岩相古地理图1幅。研究表明中上扬子地区晚二叠长兴期岩相古地理格局规律明显，自西向东依次出现剥蚀区、冲积平原、碎屑岩台地、碳酸盐岩台地、斜坡与盆地，其中碳酸盐岩台地中可以划分出低能生物滩、高能生物滩和生物礁等次一级的古地理单元。沉积环境对烃源岩的发育具有明显的控制作用，研究区大隆组优质烃源岩发育；长兴阶储层应以礁相储层为主，环广元—梁平盆地是长兴组潜伏礁型油气藏的最有利勘探区域。

The Xujiajuan Formation of the Lower Xiangshan Group in Ningxia, China, is composed of grayish-green to yellowish-green, fine- to medium-grained sandstone, calcareous sandstone, siltstone, and shale. The upper part is thin-bedded limestone. At the top of the second and third members of the formation, a number of beds intercalated between turbidites and deep-water shale show well-developed cross-bedding. These beds are composed mainly of thin- to medium-bedded calcareous siltstone, fine-grained sandstone, fine-grained calcisiltitic limestone, and silty shale. All bedding types reflect traction-current action. The laminae of the bidirectional and unidirectional cross-bedded units tend to dip either opposite to or at a large angle to the regional slope. The units vary in shape and orientation in both upslope and downslope directions. A comprehensive evaluation of the sedimentary structures and inferred paleocurrents suggests that the cross-bedded intervals were not formed by contour currents or turbidity currents, but most probably represent internal-wave and internal-tide deposits.

宁夏中奥陶统香山群为一套遭受轻微区域变质的灰绿色中2细粒长石石英砂岩、板岩、砾屑灰岩和硅质岩等，从下到上可分为徐家圈组、狼嘴子组和磨盘井组。系统地论述了香山群发育的各种深水沉积的特征及其沉积序列，认为香山群由深水原地沉积和深水异地沉积组成，其中后者主要包括浊流沉积、碎屑流沉积、内波、内潮汐沉积和深水复合流沉积。垂向组成单元自下而上依次为浊流沉积层（Ⅰ）、牵引流沉积层（Ⅱ）和半深海沉积层（Ⅲ）。这些认识不仅对进一步开展香山群的沉积学研究具有重要的意义，而且也可为该地区早古生代构造环境的研究提供重要的信息，同时也为目前在国际上引起注意的深水重力流的流体特征研究提供新的实例。

鄂尔多斯盆地西南缘陕西陇县中奥陶统平凉组主要为一套暗色页岩夹薄层粉砂岩、砂岩、灰岩及凝灰岩，可分为三个岩性段，其中第三段以灰绿、灰黑色页岩、粉砂质页岩、砂质页岩为主，夹深灰色薄层砂岩、粉砂岩、粒屑灰岩及青灰色灰化晶屑凝灰岩等。沉积环境分析表明平凉组主要为斜坡至盆地边缘沉积环境，以深水原地沉积为主，次为碎屑流和浊流沉积。第三段中部分薄层砂岩、粉砂岩中发育双向交错纹理和单向交错层理，纹层倾向既有沿斜坡向上和向下双向倾斜的，也有沿斜坡向下或沿斜坡向上单向倾斜的，但以沿斜坡向上单向倾斜的为主，它们不应是等深流沉积或浊流沉积，而应为内波、内潮汐产生的沿斜坡上下交替的流动所形成的，初步认为应属水道内潮汐沉积。

The study of internal-wave and internal-tide deposits is a new research field on sedimentology during the last ten years. Deep-water traction currents induced by internal waves and internal tides are developed on the modern sea floor, which can form not only all kinds of small scale and dispersal deep-water traction currents deposits, but also large-scale sediment wave in km-size scale. In this paper, the concepts and features of internal waves and internal tides in oceanography are introduced, and the characteristics, sedimentary sequences, sedimentary microfacies and sedimentation models of internal-wave and internal-tide deposits found and the origin of large scale sediment waves in deep sea bottom are summarized. The relationship between internal-wave and internal-tide deposits and petroleum is discussed, and finally internal-wave and internal-tide deposits are shown to be a new potential field for petroleum exploration.