Changes

=====Bioturbation-Index Estimator=====

=====Bioturbation-Index Estimator=====

The degree of bioturbation can be assessed using a 0–5 scale<ref name=Lzrea2015a /><ref name=Lzrea2015b /> (figure 1E of [[Mudstone nomenclature]]). Bioturbation tends to be subtle in mudstone strata; do not expect too many textbook-style ichnofossils because burrows tend to be obscure where matrix and fill do not differ in composition and rheology<ref name=Lzrea2015b />. Prior to mud compaction, benthos do not burrow but swim through muddy sediment with high water content (70%–90%) and disturb the sediment fabric, producing deformational structures<ref name=LbzSchbr /><ref name=Schbr2003 />. For in-depth discussions and reviews of trace fossils and trends in depth, and extent of bioturbation in fine-grained rocks, see, for example, Bromley and Ekdale<ref>Bromley, R. G., and A. A. Ekdale, 1984, Chondrites: A trace fossil indicator of anoxia in sediments: Science, v. 224, p. 872–874.</ ref>, Bromley<ref>Bromley, R. G., 1990, Trace fossils: London, Unwin Hyman, 280 p.</ref>, Pemberton et al.<ref>Pemberton, S. G., M. Spila, A. J. Pulham, T. D. Saunders, and J. A. MacEachern, D. Robbins, I. K. Sinclair, 2001, Ichnology and sedimentology of shallow to marginal marine systems: Ben Nevis and Avalon reservoirs, Jeanne d’Arc Basin: Geological Association of Canada Short Course Notes 15, 343 p.</ref><ref name=Pmbrtnea2008 />, Droser and Bottjer<ref>Droser, M. L., and D. J. Bottjer, 1986, A semiquantitative field classification of ichnofabric: Journal of Sedimentary Research, v. 56, p. 558–559</ref><ref>Droser, M. L., and D. J. Bottjer, 1988, Trends in depth and extent of bioturbation in Cambrian carbonate marine environments, western United States: Geology, v. 16, p. 233–236.</ref><ref>Droser, M. L., and D. J. Bottjer, 1989, Ordovician increase in extent and depth of bioturbation: Implications for understanding early Paleozoic ecospace utilization: Geology, v. 17, p. 850–852.</ref><ref> Droser, M. L., and D. J. Bottjer, 1991, Ichnofabric and basin analysis: Palaios, v. 6, p. 199–205.</ref>, Bottjer et al.<ref> Bottjer, D. J., M. L. Droser, and D. Jablonski, 1988, Paleoenvironmental trends in the history of trace fossils: Nature, v. 333, p. 252–255.</ref>, Bottjer and Droser<ref> Bottjer, D. J., and M. L. Droser, 1992, Paleoenvironmental patterns of biogenic sedimentary structures, in C. G. Maples, and R. R. West, eds., Trace fossils: Short Courses in Paleontology v. 5, p. 130–144.</ref>, Schieber<ref name=Schbr2003 />, Hasiotis<ref> Hasiotis, S. T., 2004, Reconnaissance of Upper Jurassic Morrison Formation ichnofossils, Rocky Mountain region, USA: Environmental, stratigraphic, and climatic significance of terrestrial and freshwater ichnocoenoses: Sedimentary Geology, v. 167, p. 177–268.</ref>, and Gerard and Bromley<ref>Gerard, J., and R. Bromley, 2008, Ichnofabrics in clastic sediments: Applications to sedimentological core studies: A practical guide: Madrid, Spain, Ibergraphi 2002 SLL, 100 p.</ref>.

The degree of bioturbation can be assessed using a 0–5 scale<ref name=Lzrea2015a /><ref name=Lzrea2015b /> (figure 1E of [[Mudstone nomenclature]]). Bioturbation tends to be subtle in mudstone strata; do not expect too many textbook-style ichnofossils because burrows tend to be obscure where matrix and fill do not differ in composition and rheology<ref name=Lzrea2015b />. Prior to mud compaction, benthos do not burrow but swim through muddy sediment with high water content (70%–90%) and disturb the sediment fabric, producing deformational structures<ref name=LbzSchbr /><ref name=Schbr2003 />. For in-depth discussions and reviews of trace fossils and trends in depth, and extent of bioturbation in fine-grained rocks, see, for example, Bromley and Ekdale<ref>Bromley, R. G., and A. A. Ekdale, 1984, Chondrites: A trace fossil indicator of anoxia in sediments: Science, v. 224, p. 872–874.</ref>, Bromley<ref>Bromley, R. G., 1990, Trace fossils: London, Unwin Hyman, 280 p.</ref>, Pemberton et al.<ref>Pemberton, S. G., M. Spila, A. J. Pulham, T. D. Saunders, and J. A. MacEachern, D. Robbins, I. K. Sinclair, 2001, Ichnology and sedimentology of shallow to marginal marine systems: Ben Nevis and Avalon reservoirs, Jeanne d’Arc Basin: Geological Association of Canada Short Course Notes 15, 343 p.</ref><ref name=Pmbrtnea2008 />, Droser and Bottjer<ref>Droser, M. L., and D. J. Bottjer, 1986, A semiquantitative field classification of ichnofabric: Journal of Sedimentary Research, v. 56, p. 558–559</ref><ref>Droser, M. L., and D. J. Bottjer, 1988, Trends in depth and extent of bioturbation in Cambrian carbonate marine environments, western United States: Geology, v. 16, p. 233–236.</ref><ref>Droser, M. L., and D. J. Bottjer, 1989, Ordovician increase in extent and depth of bioturbation: Implications for understanding early Paleozoic ecospace utilization: Geology, v. 17, p. 850–852.</ref><ref> Droser, M. L., and D. J. Bottjer, 1991, Ichnofabric and basin analysis: Palaios, v. 6, p. 199–205.</ref>, Bottjer et al.<ref> Bottjer, D. J., M. L. Droser, and D. Jablonski, 1988, Paleoenvironmental trends in the history of trace fossils: Nature, v. 333, p. 252–255.</ref>, Bottjer and Droser<ref> Bottjer, D. J., and M. L. Droser, 1992, Paleoenvironmental patterns of biogenic sedimentary structures, in C. G. Maples, and R. R. West, eds., Trace fossils: Short Courses in Paleontology v. 5, p. 130–144.</ref>, Schieber<ref name=Schbr2003 />, Hasiotis<ref> Hasiotis, S. T., 2004, Reconnaissance of Upper Jurassic Morrison Formation ichnofossils, Rocky Mountain region, USA: Environmental, stratigraphic, and climatic significance of terrestrial and freshwater ichnocoenoses: Sedimentary Geology, v. 167, p. 177–268.</ref>, and Gerard and Bromley<ref>Gerard, J., and R. Bromley, 2008, Ichnofabrics in clastic sediments: Applications to sedimentological core studies: A practical guide: Madrid, Spain, Ibergraphi 2002 SLL, 100 p.</ref>.

=====Consistency of Marine Substrate=====

=====Consistency of Marine Substrate=====