2 Mudstone Nomenclature
O. R. Lazar, Kevin M. Bohacs, Jüergen Schieber, J. H. S. Macquaker, Timothy M. Demko
Abstract
ABSTRACT This chapter introduces the key aspects of mudstone and the naming scheme we recommend and use when characterizing mudstone in outcrops, cores, and thin sections. This naming scheme is based on three key rock attributes: texture, bedding, and composition. This scheme has been designed to enable textural (grain size), bedding, compositional, and grain origin attributes to be captured and compared consistently for the entire spectrum of fine-grained sedimentary rocks and across a range of scales—from hand specimen to scanning electron microscopy image. Texture, composition, bedding, and grain origin are important for the following reasons: This chapter presents the key aspects of texture, bedding, and composition; guidelines for describing these aspects; and applications and complications of this approach. Lazar et al. (2022a, Chapter 3 this Memoir) provides an overview of the tools and practical workflows we use to facilitate consistent, repeatable, and efficient capture of mudstone texture, bedding, and composition in outcrops, cores, and thin sections.