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三角洲朝海洋一侧的能量条件,可分成河流作用为主的、波浪作用为主的,以及潮汐作用为主的三种三角洲。每种三角洲具有各自互不相同的骨架方向及沉积模式,因而形成了各自特有的地震反射模式。河流作用为主的三角洲具有倾斜反射模式的特征,这类模式包括:斜交(切向)、复合斜交(切向)、反S形及复合反S形一斜交几种。地震相分析可用来确定含砂的地震相。波浪作用为主的三角洲具有迭瓦状地震反射模式的特征。这种三角洲的地震相分析对鉴定那些很可能是富砂相无效。迭瓦状反射可以用来判定滨岸砂的可能位置及其沉积形态。潮汐作用为主的三角洲尚未采用过地震地层学方法进行鉴定,因此本文不涉及这一内容。浊积扇是在盆地或海底峡谷中沉积下来的砂和页岩层序。浊积砂一般可分为水道砂与冲积扇砂两种。以各种不同组合形式出现的某些地震同相轴和反射模式可以揭示有浊积岩的存在。这些揭示包括海槽、海底峡谷、丘状构造、厚度变化的河流作用为主的前积三角洲反射模式以及沉积斜坡上的上超一退复模式。区域研究是鉴定沉积层序并绘制成图的最佳途径。北海,墨西哥湾沿岸及圣克利门特河谷的例子均阐明了三角洲与浊积层序的这种地质和地球物理表现形式及其相互关系。
The energy conditions on the delta side toward the ocean can be divided into three kinds of rivers, mainly wave-based and tidal-based. Each delta has its own different skeleton orientation and deposition mode, thus forming their own unique seismic reflection mode. The river-dominated deltas are characterized by oblique reflection patterns. These patterns include skew (cross), compound skew (tangential), inverse S-shaped and compound inverse S-shaped skew. Seismic facies analysis can be used to determine the sand-containing seismic facies. The wave-dominated delta has the characteristics of a Diego-like seismic reflection mode. Seismic facies analyzes of this delta are not valid for identifying those that are likely to be sand-rich phases. Diego-like reflection can be used to determine the possible location of shore sand and its sedimentary morphology. The tidal-dominated delta has not been identified by seismic stratigraphy, so this article does not cover this. Turbidite fans are sand and shale sequences deposited in basins or submarine canyons. Turbidity sand can generally be divided into channel sands and alluvial fan sand two. Some seismic events and reflection patterns that occur in various combinations reveal the presence of turbidite. These revelations include the pre-delta reflection model dominated by troughs, submarine canyons, mound-shaped structures, river with varying thickness, and the suprasperitoneal pattern of retrogradation on sedimentary slopes. Regional studies are the best way to identify sedimentary sequences and map them. Examples of such geological and geophysical manifestations of delta and turbidity sequences and their relationships are illustrated in the North Sea, Gulf Coast, and St Clement Valley.