CHARACTERISTICS AND SEDIMENTOLOGICAL SIGNIFICANCE OF THE FORMS, BODlES AND STRUCTURES ORIGINATED BY FLUID AGENTS.

Abstract

A review of tractive· sedimentary structures, such as ripples, megaripples and cross-bedding, and the definition of sedimentary bodies and sedimentary forms are considered in this paper. Sedimentary bodies are groups of strata which can be differentiated from adjacent beds beca use of the presence of first order bounding surfaces. Sedimentary forms are features (such as bars, ribbons, crests, ridges, channels, dunes, etc.) originated by the agents of clastic deposition. Sedimentary forms are difficult to recognize in ancient sequences, but they may be inferred by analyzing both the type and distribution of sedimentary structures and sedimentary bodies. Sedimentary bodies are generally the features of sedimentary forms preserved in the geological record. The scale and significance of first, second ancl third order bouncling surfaces developecl in f1uviatile, marine and eolian seclimentary sequences are also treatecl in this contribution.