Changes

A clean, dry rock surface is an essential prerequisite to any form of visual examination. The time spent preparing fine-grained rocks is amply rewarded by the many details revealed ([[:file:M91Ch6FG47.JPG|Figure 1]]). A list of tools and supplies we recommend for preparing fresh rock surfaces and describing mudstones in outcrops and cores is given in Table 1. We recommend the following tools and approaches for preparing mudstone surfaces for visual examination:

A clean, dry rock surface is an essential prerequisite to any form of visual examination. The time spent preparing fine-grained rocks is amply rewarded by the many details revealed ([[:file:M91Ch6FG47.JPG|Figure 1]]). A list of tools and supplies we recommend for preparing fresh rock surfaces and describing mudstones in outcrops and cores is given in Table 1. We recommend the following tools and approaches for preparing mudstone surfaces for visual examination:

''Table 1. Suggested List of Equipment and Supplies for Describing Mudstones (after Lazar et al.<ref name=Lzrea2015b />).''

'''Table 1. Suggested List of Equipment and Supplies for Describing Mudstones (after Lazar et al.<ref name=Lzrea2015b />).'''

* Backpack

* Backpack

* Geologic hammer

* Geologic hammer

¹supplemental gear for core description.

¹supplemental gear for core description.

* ‘’Sharp-rock saw:’’ Prepare a flat, relatively polished surface. A portable concrete saw can be used in the field to acquire continuous, perpendicular-to-bedding slot samples; samples should be stabilized with fiberglass matting and epoxy resin prior to removal<ref name=Schber1998b />.

* '''Sharp-rock saw:''' Prepare a flat, relatively polished surface. A portable concrete saw can be used in the field to acquire continuous, perpendicular-to-bedding slot samples; samples should be stabilized with fiberglass matting and epoxy resin prior to removal<ref name=Schber1998b />.

* ‘’Clean:’’ Scrub and polish using a paint brush, scrub brush, abrasive paper or sponge (polished using a series of sandpaper of grades from no. 80 to no. 800 grit); scrubbing pad (softer—white and harder—green); or pencil eraser (∼1 in. wide, pink or white). Pencil erasers can be quite effective for removing dust, precipitated minerals, or oil-based mud from slabbed-core pieces. Beware of rocks that are sensitive to water—minimize exposure time and dry each piece immediately, using compressed air, if possible, or a clean absorbent material (e.g., paper towel). Use a dilute degreasing solution on cores taken with oil-based mud.

* '''Clean:''' Scrub and polish using a paint brush, scrub brush, abrasive paper or sponge (polished using a series of sandpaper of grades from no. 80 to no. 800 grit); scrubbing pad (softer—white and harder—green); or pencil eraser (∼1 in. wide, pink or white). Pencil erasers can be quite effective for removing dust, precipitated minerals, or oil-based mud from slabbed-core pieces. Beware of rocks that are sensitive to water—minimize exposure time and dry each piece immediately, using compressed air, if possible, or a clean absorbent material (e.g., paper towel). Use a dilute degreasing solution on cores taken with oil-based mud.

* ‘’Contrast enhancement techniques:’’ Several approaches are available that are fast, simple, and useful for visualizing sedimentary details if further geochemical analyses of the studied rocks are not planned. Many of these approaches are summarized in the literature<ref>Ekdale, A. A., R. G. Bromley, and S. G. Pemberton, 1984, Ichnology: Trace fossils in sedimentology and stratigraphy: SEPM Short Course Notes, v. 15, p. 317.</ref><ref name=Mllr1988>Miller, J., 1988, Microscopical techniques: I. Slices, slides, stains and peels, in M. E. Tucker, ed., Techniques in sedimentology: Oxford, U.K., Blackwell Scientific Publications, p. 86–107.</ref><ref>Scholle, P. A., and D. Ulmer-Scholle, 2003, A color guide to the petrography of carbonate rocks: Grains, textures, porosity, diagenesis: [https://archives.datapages.com/data/alt-browse/aapg-special-volumes/m77.htm AAPG Memoir 77], 474 p.</ref><ref name=Flgl2010>Flügel, E., 2010, Microfacies of carbonate rocks: Analysis, interpretation and application, 2nd ed.: Berlin, Springer-Verlag, 984 p.</ref>; some of these approaches are:

* '''Contrast enhancement techniques:''' Several approaches are available that are fast, simple, and useful for visualizing sedimentary details if further geochemical analyses of the studied rocks are not planned. Many of these approaches are summarized in the literature<ref>Ekdale, A. A., R. G. Bromley, and S. G. Pemberton, 1984, Ichnology: Trace fossils in sedimentology and stratigraphy: SEPM Short Course Notes, v. 15, p. 317.</ref><ref name=Mllr1988>Miller, J., 1988, Microscopical techniques: I. Slices, slides, stains and peels, in M. E. Tucker, ed., Techniques in sedimentology: Oxford, U.K., Blackwell Scientific Publications, p. 86–107.</ref><ref>Scholle, P. A., and D. Ulmer-Scholle, 2003, A color guide to the petrography of carbonate rocks: Grains, textures, porosity, diagenesis: [https://archives.datapages.com/data/alt-browse/aapg-special-volumes/m77.htm AAPG Memoir 77], 474 p.</ref><ref name=Flgl2010>Flügel, E., 2010, Microfacies of carbonate rocks: Analysis, interpretation and application, 2nd ed.: Berlin, Springer-Verlag, 984 p.</ref>; some of these approaches are:

** ‘’Etching’’ in dilute hydrochloric acid<ref name=Flgl2010 />: excellent for enhancing texture.

** '''Etching''' in dilute hydrochloric acid<ref name=Flgl2010 />: excellent for enhancing texture.

** ‘’Wetting’’ with water<ref> Frey, R. W., 1970, The Lebenspurren of some common marine invertebrates near Beaufort, North Carolina. 2, Anemone burrow: Journal of Paleontology, v. 44, p. 308–311.</ref>: excellent for emphasizing bioturbation.

** '''Wetting''' with water<ref> Frey, R. W., 1970, The Lebenspurren of some common marine invertebrates near Beaufort, North Carolina. 2, Anemone burrow: Journal of Paleontology, v. 44, p. 308–311.</ref>: excellent for emphasizing bioturbation.

** ‘’Staining’’ with an ink: Alizarin Red S<ref>Hamblin, W. K., 1962, Staining and etching techniques for studying obscure structures in clastic rocks: Journal of Sedimentary Petrology, v. 32, p. 201–210.</ref><ref> Farrow, G. E., 1966, Bathymetric zonation of Jurassic trace fossils: Palaeogeography, Palaeoclimate, Palaeoecology, v. 2, p. 103–151.</ref>, a mixture of India ink and carborundum powder<ref> West, I. M., 1965, A new method of displaying microstructures in porous limestone: Journal of Sedimentary Petrology, v. 35, p. 250–251.</ref>, and periodic acid–Schiff<ref>Risk, M. J., and R. B. Szczuczko, 1977, A Method for Staining Trace Fossils: Journal of Sedimentary Petrology, v. 47, no. 2, p. 855–859.</ref>; excellent for identifying composition and porosity<ref name=Flgl2010 /><ref name=Frdmn1959>Friedman, G. M., 1959, Identification of carbonate minerals by staining methods: Journal of Sedimentary Petrography, v. 29, p. 87–97.</ref><ref name=Evmy1963>Evamy, B. D., 1963, The application of a chemical staining technique to a study of dedolomitisation: Sedimentology, v. 2, no. 2, p. 164–170. doi:10.1111/j.1365-3091.1963.tb01210.x.</ref><ref>Yanguas, J. E., and J. J. Dravis, 1985, Blue fluorescent dye technique for recognition of microporosity in sedimentary rocks: Journal of Sedimentary Petrology, v. 55, no. 4, p. 600–602.</ref>.

** '''Staining''' with an ink: Alizarin Red S<ref>Hamblin, W. K., 1962, Staining and etching techniques for studying obscure structures in clastic rocks: Journal of Sedimentary Petrology, v. 32, p. 201–210.</ref><ref> Farrow, G. E., 1966, Bathymetric zonation of Jurassic trace fossils: Palaeogeography, Palaeoclimate, Palaeoecology, v. 2, p. 103–151.</ref>, a mixture of India ink and carborundum powder<ref> West, I. M., 1965, A new method of displaying microstructures in porous limestone: Journal of Sedimentary Petrology, v. 35, p. 250–251.</ref>, and periodic acid–Schiff<ref>Risk, M. J., and R. B. Szczuczko, 1977, A Method for Staining Trace Fossils: Journal of Sedimentary Petrology, v. 47, no. 2, p. 855–859.</ref>; excellent for identifying composition and porosity<ref name=Flgl2010 /><ref name=Frdmn1959>Friedman, G. M., 1959, Identification of carbonate minerals by staining methods: Journal of Sedimentary Petrography, v. 29, p. 87–97.</ref><ref name=Evmy1963>Evamy, B. D., 1963, The application of a chemical staining technique to a study of dedolomitisation: Sedimentology, v. 2, no. 2, p. 164–170. doi:10.1111/j.1365-3091.1963.tb01210.x.</ref><ref>Yanguas, J. E., and J. J. Dravis, 1985, Blue fluorescent dye technique for recognition of microporosity in sedimentary rocks: Journal of Sedimentary Petrology, v. 55, no. 4, p. 600–602.</ref>.

** ‘’Modified Bushinsky oil technique’’<ref>Bushinsky, G. I., 1947, Textures and structures of Cretaceous chalk and flints (Russian with English summary): Bulletin of Society of Naturalists, Moscow, New Series 52 (Geology), v. 22, p. 37–43.</ref><ref>Bromley, R. G., 1981, Enhancement of visibility of structures in marly chalk: Modification of the Bushinsky oil technique: Bulletin of the Geological Society of Denmark, v. 29, p. 111–118.</ref>: excellent for enhancing the visibility of internal structures and details of fabric in chalk. Samples are slabbed, polished, and then painted with lightweight oil.

** '''Modified Bushinsky oil technique'''<ref>Bushinsky, G. I., 1947, Textures and structures of Cretaceous chalk and flints (Russian with English summary): Bulletin of Society of Naturalists, Moscow, New Series 52 (Geology), v. 22, p. 37–43.</ref><ref>Bromley, R. G., 1981, Enhancement of visibility of structures in marly chalk: Modification of the Bushinsky oil technique: Bulletin of the Geological Society of Denmark, v. 29, p. 111–118.</ref>: excellent for enhancing the visibility of internal structures and details of fabric in chalk. Samples are slabbed, polished, and then painted with lightweight oil.

====Light Sources====

====Light Sources====