includes the texture
of a rock
and the small scale rock structures. The words "texture" and "microstructure" are interchangeable, with the latter preferred in modern geological literature. However, texture is still acceptable because it is a useful means of identifying the origin of rocks, how they formed, and their appearance.
Textures are penetrative fabric
of rocks; they occur throughout the entirety of the rock mass on a microscopic, hand specimen and often on an outcrop scale. This is similar in many ways to foliations
, except a texture does not necessarily carry structural information in terms of deformation events and orientation information. Structures
occur on hand-specimen scale and above.
Microstructure analysis describes the textural features of the rock, and can provide information on the conditions of formation, petrogenesis, and subsequent deformation, folding or alteration events.
Description of sedimentary rock
microstructure aims to provide information on the conditions of deposition of the sediment
, the paleo-environment
, and the provenance of the sedimentary material.
Methods involve description of clast size, sorting, composition, rounding or angularity, sphericity and description of the matrix. Sedimentary microstructures, specifically, may include microscopic analogs of larger sedimentary structural features such as cross-bedding
, syn-sedimentary faults, sediment slumping,... Read More