Changes

Sequence-stratigraphic analyses rely on a firm understanding of the nature and character of the rocks under consideration to properly recognize the expression of stratigraphic surfaces and stratal packages in particular depositional systems. In addressing the nature of FGRs, there has been a significant variation in the usage of some of the terms used to describe these rocks. For a detailed discussion and comparison of different terms and classifications of FGRs, see [[Mudstone nomenclature]], as well as Ingram<ref>Ingram, R. L., 1953, Fissility of mudrocks: Bulletin of Geological Society of America, v. 64, p. 869–878.</ref>; Tourtelot<ref>Tourtelot, H. A., 1960, Origin and use of the word “shale”: American Journal of Science, v. 258A, p. 335–343.</ref>; Folk<ref> Folk, R. L., 1965, Petrology of sedimentary rocks, 1st edition: Austin, Texas, Hemphill’s, 159 p.</ref><ref>Folk, R. L., 1968, Petrology of sedimentary rocks, 2nd edition: Austin, Texas, Hemphill’s, 170 p.</ref>; Picard<ref>Picard, D. M., 1971, Classification of fine-grained sedimentary rocks: Journal of Sedimentary Petrology, v. 41, p. 179–195.</ref>; Blatt et al.<ref>Blatt, H., G. Middleton, and R. Murray, 1980, Origin of sedimentary rocks: Englewood Cliffs, New Jersey, Prentice-Hall, Inc., 782 p.</ref>; Lundegard and Samuels<ref>Lundegard, P. D., and N. D. Samuels, 1980, Field classification of fine-grained sedimentary rocks: Journal of Sedimentary Petrology, v. 50, p. 781–786.</ref>; Potter et al.<ref>Potter, P. E., J. B. Maynard, and W. A. Pryor, 1980, Sedimentology of shale: Study guide and reference source: New York, Springer-Verlag, 303 p.</ref><ref>Potter, P. E., J. B. Maynard, and P. J. Depetris, 2005, Mud and mudstones: Introduction and overview: New York, Springer, 297 p.</ref>; Spears<ref>Spears, D. A., 1980, Towards a classification of shales: Journal of the Geological Society of London, v. 137, p. 125–129.</ref>; Stow<ref>Stow, D. A., 1981, Fine-grained sediments: Terminology: Quarterly Journal of Engineering Geology and Hydrology, v. 14, p. 243–244.</ref>; Macquaker and Adams<ref>Macquaker, J. H. S., and A. E. Adams, 2003, Maximizing information from fine-grained sedimentary rocks: An inclusive nomenclature for mudstones: Journal of Sedimentary Research, v. 73, p. 735–744.</ref>; Lazar et al.<ref name=Lzr2010>Lazar, O. R., K. M. Bohacs, J. H. S. Macquaker, and J. Schieber, 2010, Fine-grained rocks in outcrops: Classification and description guidelines, in J. Schieber, O. R. Lazar, and K. M. Bohacs, eds., Sedimentology and stratigraphy of shales: Expressions and correlation of depositional sequences in the Devonian of Tennessee, Kentucky, and Indiana: AAPG Field Guide for SEPM Field Trip 10, p. 3–14.</ref>/><ref name=Lzr2015a /><ref name=Lzr2015b>Lazar, O. R., K. M. Bohacs, J. Schieber, J. H. S. Macquaker, and T. M. Demko, 2015b, Mudstone primer: Lithofacies variations, diagnostic criteria, and sedimentologic/stratigraphic implications at lamina to bedset scales: SEPM Concepts in Sedimentology and Paleontology 12, 200 p.</ref>. Here, we recommend the use of “mudstone” as a class name for all FGRs based on their key attribute of grain size, in direct analogy with other sedimentary rock names such as “sandstone” and “limestone.” The following are the key attributes of mudstone to keep in mind throughout this book and in your interpretation of mudstone strata.

Sequence-stratigraphic analyses rely on a firm understanding of the nature and character of the rocks under consideration to properly recognize the expression of stratigraphic surfaces and stratal packages in particular depositional systems. In addressing the nature of FGRs, there has been a significant variation in the usage of some of the terms used to describe these rocks. For a detailed discussion and comparison of different terms and classifications of FGRs, see [[Mudstone nomenclature]], as well as Ingram<ref>Ingram, R. L., 1953, Fissility of mudrocks: Bulletin of Geological Society of America, v. 64, p. 869–878.</ref>; Tourtelot<ref>Tourtelot, H. A., 1960, Origin and use of the word “shale”: American Journal of Science, v. 258A, p. 335–343.</ref>; Folk<ref> Folk, R. L., 1965, Petrology of sedimentary rocks, 1st edition: Austin, Texas, Hemphill’s, 159 p.</ref><ref>Folk, R. L., 1968, Petrology of sedimentary rocks, 2nd edition: Austin, Texas, Hemphill’s, 170 p.</ref>; Picard<ref>Picard, D. M., 1971, Classification of fine-grained sedimentary rocks: Journal of Sedimentary Petrology, v. 41, p. 179–195.</ref>; Blatt et al.<ref>Blatt, H., G. Middleton, and R. Murray, 1980, Origin of sedimentary rocks: Englewood Cliffs, New Jersey, Prentice-Hall, Inc., 782 p.</ref>; Lundegard and Samuels<ref>Lundegard, P. D., and N. D. Samuels, 1980, Field classification of fine-grained sedimentary rocks: Journal of Sedimentary Petrology, v. 50, p. 781–786.</ref>; Potter et al.<ref>Potter, P. E., J. B. Maynard, and W. A. Pryor, 1980, Sedimentology of shale: Study guide and reference source: New York, Springer-Verlag, 303 p.</ref><ref>Potter, P. E., J. B. Maynard, and P. J. Depetris, 2005, Mud and mudstones: Introduction and overview: New York, Springer, 297 p.</ref>; Spears<ref>Spears, D. A., 1980, Towards a classification of shales: Journal of the Geological Society of London, v. 137, p. 125–129.</ref>; Stow<ref>Stow, D. A., 1981, Fine-grained sediments: Terminology: Quarterly Journal of Engineering Geology and Hydrology, v. 14, p. 243–244.</ref>; Macquaker and Adams<ref>Macquaker, J. H. S., and A. E. Adams, 2003, Maximizing information from fine-grained sedimentary rocks: An inclusive nomenclature for mudstones: Journal of Sedimentary Research, v. 73, p. 735–744.</ref>; Lazar et al.<ref name=Lzr2010>Lazar, O. R., K. M. Bohacs, J. H. S. Macquaker, and J. Schieber, 2010, Fine-grained rocks in outcrops: Classification and description guidelines, in J. Schieber, O. R. Lazar, and K. M. Bohacs, eds., Sedimentology and stratigraphy of shales: Expressions and correlation of depositional sequences in the Devonian of Tennessee, Kentucky, and Indiana: AAPG Field Guide for SEPM Field Trip 10, p. 3–14.</ref>/><ref name=Lzr2015a /><ref name=Lzr2015b>Lazar, O. R., K. M. Bohacs, J. Schieber, J. H. S. Macquaker, and T. M. Demko, 2015b, Mudstone primer: Lithofacies variations, diagnostic criteria, and sedimentologic/stratigraphic implications at lamina to bedset scales: SEPM Concepts in Sedimentology and Paleontology 12, 200 p.</ref>. Here, we recommend the use of “mudstone” as a class name for all FGRs based on their key attribute of grain size, in direct analogy with other sedimentary rock names such as “sandstone” and “limestone.” The following are the key attributes of mudstone to keep in mind throughout this book and in your interpretation of mudstone strata.

[[File:M126-Mudstones-Fig1.jpeg|thumb|500px|{{figure number|1}}Major biological evolutionary events through time and examples of pore types in mudstone. (A) and (F): pores in the mineral matrix; (B–E) and (G): pores in the organic matter. These evolutionary changes influence oil and gas yields and hydrocarbon generation kinetics, porosity development, and the occurrence, composition, and diagenetic behavior of the “hard” components as they influence deformation because of burial, tectonic, and human-induced stress. They also affect essential relations used in formation evaluation models (e.g., total organic carbon [TOC] versus uranium; clay minerals versus thorium or potassium; pyrite and TOC versus bulk density; after Bohacs et al. .<ref name=Bhcs2014a />). Oc. Chem. = ocean chemistry. Green algae photo courtesy of Dr. Yow-Yuh Chen.]]

[[File:M126-Mudstones-Fig1.jpeg|center|framed|300px|{{figure number|1}}Major biological evolutionary events through time and examples of pore types in mudstone. (A) and (F): pores in the mineral matrix; (B–E) and (G): pores in the organic matter. These evolutionary changes influence oil and gas yields and hydrocarbon generation kinetics, porosity development, and the occurrence, composition, and diagenetic behavior of the “hard” components as they influence deformation because of burial, tectonic, and human-induced stress. They also affect essential relations used in formation evaluation models (e.g., total organic carbon [TOC] versus uranium; clay minerals versus thorium or potassium; pyrite and TOC versus bulk density; after Bohacs et al. .<ref name=Bhcs2014a />). Oc. Chem. = ocean chemistry. Green algae photo courtesy of Dr. Yow-Yuh Chen.]]

 

Mudstone, similar to sandstone or grainstone, is deposited layer by layer, in sequential order. Its present-day attributes are the result of the sediment history: provenance, weathering and erosion, transport, deposition, and diagenesis.

Mudstone, similar to sandstone or grainstone, is deposited layer by layer, in sequential order. Its present-day attributes are the result of the sediment history: provenance, weathering and erosion, transport, deposition, and diagenesis.