Mudstone 1 : Natural Disaster. Sedimentary rocks that consist of particles finer than sand grade (less than 0.0625 mm) and include both silt and clay grade material. Also called shales
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}