Groundmass (s-matrix of Brewer) is a general term used for the coarse and/or fine material which forms the base material of teh soil, other than that in pedological features except in the following two cases: 1) where the pedofeatures have arisen through impregnation of the groundmass and the groundmass is still evident; 2) on a rather different level, when making a detailed description of a pedofeature, it is sometimes convenient to refer to the base material of the pedofeature as groundmass.; Groundmass is thus a partial fabric but not of pedofeatures other than in the cases noted above. Some soil materials consist only of groundmass (e.g. very young soils without pedofeatures).
The arrangement of teh Coarse Material is described using terms for basic or referred distribution patterns to be discussed later. The arrangement of detrital grains in soil materials is usually random.
List of the most important detrital grains and most important pedogenic minerals in soils. Copied from Tables 6.1 and 6.2 of Bullock, P. et al. (eds.) 1985. handbook for thin section description. WAINE Research Publication. Albrighton, Woverhampton, England.
Micromass is a general term for the finer material in the groundmass. This term is used in preference to "matrix", which has had various definitions.
The fabric of the Fine Material is concerned with the arrangement (orientation and distribution), size and shape of the constituents of the fine material. The individual particles in the fine material cannot normally be seen with the optical microscope because fo their relatively small size. However, the arrangement of teh micromass particles exhibit patterns of interference colors giving information on the orientation patterns of anisotropic clay minerals. Using the opticla phenomena of clay aggregates under the polarizing microscope, the fabric of the fine mass can be described by the orientation and distribution of the patterns of interference colors and their optical natrue. This observed fabric is called the birefringence fabric or b-fabric of the fine material. It is related to the plasmic fabric of Brewer.
This page (http://www.ces.ncsu.edu/plymouth/programs/ground.html) created by
Vera MacConnell, Research Technician, I on February 4, 1998.
Last Updated on February 4, 1998.
