Changes

=====Grain-Size Charts=====

=====Grain-Size Charts=====

These charts classify sediments and sedimentary rocks based on the range of the diameter of individual grains<ref>Udden, J. A., 1914, Mechanical composition of clastic sediments: Geological Society of America Bulletin, v. 25, p. 655–744.</ref><ref>Wentworth, C. K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology, v. 30, p. 377–392.

These charts classify sediments and sedimentary rocks based on the range of the diameter of individual grains<ref>Udden, J. A., 1914, Mechanical composition of clastic sediments: Geological Society of America Bulletin, v. 25, p. 655–744.</ref><ref>Wentworth, C. K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology, v. 30, p. 377–392.

</ref><ref>Krumbein, W. C., and L. L. Sloss, 1963, Stratigraphy and sedimentation, 2nd ed.: San Francisco, Freeman Press, 660 p.</ref>. See [[Mudstone nomenclature]] for a discussion and definitions of mud grain-size boundaries. As a reminder, before examination of mudstone strata, it is important to obtain and examine fresh surfaces of rocks from each potential stratigraphic package. Then, estimate the percentage of sand-size grains with visual comparison to percentage charts. If less than 50 % are sand-sized grains, the rock is a mudstone and next, a scratch test can be performed to determine the dominant grain size<ref name=Lzrea2022a>.

</ref><ref>Krumbein, W. C., and L. L. Sloss, 1963, Stratigraphy and sedimentation, 2nd ed.: San Francisco, Freeman Press, 660 p.</ref>. See [[Mudstone nomenclature]] for a discussion and definitions of mud grain-size boundaries. As a reminder, before examination of mudstone strata, it is important to obtain and examine fresh surfaces of rocks from each potential stratigraphic package. Then, estimate the percentage of sand-size grains with visual comparison to percentage charts. If less than 50 % are sand-sized grains, the rock is a mudstone and next, a scratch test can be performed to determine the dominant grain size<ref name=Lzrea2022a />.

=====Percentage-Estimation Charts=====

=====Percentage-Estimation Charts=====