Palynology, petrology, and depositional environments of some early tertiary lignites in Texas

Abstract

Abstract Predominantly nonmarine early Tertiary sediments of the Wilcox Group in Texas include numerous local lignite deposits. Recent subsurface mapping has defined several interrelated depositional systems representing six sedimentary environments, in outcropping and subsurface Wilcox in Texas. Lignite occurs in three of the environments so defined; these are (1) fluvial, (2) deltaic, and (3) lagoonal. Plant microfossils and coal macerals from the Wilcox lignites comprise a relatively homogenous, recurring association, but substantial differences also exist between the lignites from the various environments. Petrographic differences include: (1) greater abundances of certain lithotypes, (2) predominance of certain macerals, (3) relative abundance of mineral matter. Palynologic differences can be summarized in terms of distribution of assemblages and species groups within the flora. Assemblages recognized are the (1) Corylus‐Sphagnum Assemblage, (2) Palm Assemblage, and (3) Marine Influence Assemblage. S...