Texture prograding

Shape bank Texture prograding, sigmoid Shape slope front fill Texture parallel, even... 

Detailed mineralogical and textural analysis of Ugnu Formation has been conducted by Mowatt et al. (1991) and Hallam et al. (1991). The sand bodies with good reservoir parameters in the Lower Ugnu Formation were deposited by the distributary channels of a prograding delta. The coarse channel sands are... 

All the shapes mentioned above can consist of different textures. A sheet geometry, for example, can contain several textures simultaneously, e.g. a chaotic texture and a parallel texture side by side. On the other hand, there is no texture that is restricted only to a certain shape. Prograding textures, for example, can occur in almost all shapes. 

Prograding sub-Texture Sigmoid. This texture shows S-shaped reflections with thin, gently dipping upper and lower segments. The upper segments show almost horizontal dips. The middle segments are thicker and form lenses. 

Prograding sub-Texture Tangential-Oblique. The dips of the clinoforms decrease in lower portions forming concave-upward strata which pass into gently dipping bottomset strata. This texture indicates low to moderate energy and points to a decrease in grain size downslope. 

Prograding sub-Texture Hummocky Clinoforms. This texime consists of irregular discontinuous subparallel reflections forming a practically random hummocky pattern marked by nonsystematic reflection terminations and splits. Hummocky clinoforms are indicative for deltaic lobes prograding into shallow water. 

Fig. 10. Different channel fiU textures (a) onlap fill, (b) mounded onlap fill, (c) divergent fill, (d) prograded fiU, (e) chaotic fiU, and (f) complex fill (modified after...

Channels can show different types of textures due to various Ailing mechanisms and size, aspect ratio, sinuosity, etc. We can differentiate onlap All, prograded fill (progradational clinoforms can have all the shapes described in Subsection 4.2), mounded onlap fill (in this case the channel top is convex upward), chaotic fill, divergent fill, and complex fill. 

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