Changes

The steps of the workflow we recommend for examining mudstones in outcrops, cores, and thin sections are:

The steps of the workflow we recommend for examining mudstones in outcrops, cores, and thin sections are:

# ‘’Make observations’’

# '''Make observations'''

## ‘’Establish stratigraphic context’’

## '''Establish stratigraphic context'''

### Step back, examine, and photograph the entire exposure, walking the section several times.

### Step back, examine, and photograph the entire exposure, walking the section several times.

### Check core depths and core box order, clean the core, and photograph the entire core. Step back, examine, and walk the section several times with well logs in hand.

### Check core depths and core box order, clean the core, and photograph the entire core. Step back, examine, and walk the section several times with well logs in hand.

### Look for changes in texture, bedding, composition, thickness, continuity, and stacking; and presence of erosional surfaces. Tentatively identify stratigraphic packages.

### Look for changes in texture, bedding, composition, thickness, continuity, and stacking; and presence of erosional surfaces. Tentatively identify stratigraphic packages.

### Make note of weathering characteristics and their vertical and lateral distribution.

### Make note of weathering characteristics and their vertical and lateral distribution.

## ‘’Start at the base of the section or core, identify, examine, and describe stratigraphic packages and surfaces as you proceed up-section. Integrate outcrop or core observations with thin-section observations.’’ Observe and take pictures of stratigraphic features at all scales (laminae, laminasets, beds, bedsets, parasequences, parasequence sets, and sequences).

## '''Start at the base of the section or core, identify, examine, and describe stratigraphic packages and surfaces as you proceed up-section. Integrate outcrop or core observations with thin-section observations.''' Observe and take pictures of stratigraphic features at all scales (laminae, laminasets, beds, bedsets, parasequences, parasequence sets, and sequences).

### Examine a fresh face of rocks from each potential stratigraphic package; sample each significant facies; mudstones tend to weather deeply and may require much digging to remove the weathered rock and to obtain fresh exposure and samples ([[:file:M91Ch6FG47.JPG|Figure 1]]).

### Examine a fresh face of rocks from each potential stratigraphic package; sample each significant facies; mudstones tend to weather deeply and may require much digging to remove the weathered rock and to obtain fresh exposure and samples ([[:file:M91Ch6FG47.JPG|Figure 1]]).

### Describe the mudstones: ‘’texture, bedding,’’ and ‘’composition’’. Figure 1A–D in [[Mudstone nomenclature]] summarize the terms and definitions we recommend for texture, bedding, and composition. A practical, proxy method, the “scratch test,” we recommend to use to determine the dominant grain size at hand specimen scale is detailed in [[:file:M126Ch3-Table10.jpeg|Table 10]]. Fine-tune outcrop and core estimations of texture, bedding, and composition by integrating observations under optical and electronic microscopes and analytical data obtained on samples taken in sedimentologic and stratigraphic context.

### Describe the mudstones: '''texture, bedding,''' and '''composition'''. Figure 1A–D in [[Mudstone nomenclature]] summarize the terms and definitions we recommend for texture, bedding, and composition. A practical, proxy method, the “scratch test,” we recommend to use to determine the dominant grain size at hand specimen scale is detailed in [[:file:M126Ch3-Table10.jpeg|Table 10]]. Fine-tune outcrop and core estimations of texture, bedding, and composition by integrating observations under optical and electronic microscopes and analytical data obtained on samples taken in sedimentologic and stratigraphic context.

### Describe biogenic sedimentary structures and characterize the degree of bioturbation using a 0–5 scale (figure 1E of [[Mudstone nomenclature]]).

### Describe biogenic sedimentary structures and characterize the degree of bioturbation using a 0–5 scale (figure 1E of [[Mudstone nomenclature]]).

### Describe the type, size, diversity, abundance (figure 1F of [[Mudstone nomenclature]]), preservation, and taphonomy (figure 1G of [[Mudstone nomenclature]]) of body fossils. Similarly, describe trace fossils.

### Describe the type, size, diversity, abundance (figure 1F of [[Mudstone nomenclature]]), preservation, and taphonomy (figure 1G of [[Mudstone nomenclature]]) of body fossils. Similarly, describe trace fossils.

### Describe the type, size, composition, and abundance of diagenetic products (figures 1C, F of [[Mudstone nomenclature]]).

### Describe the type, size, composition, and abundance of diagenetic products (figures 1C, F of [[Mudstone nomenclature]]).

### Organize recurring, representative, and diagnostic facies attributes into ‘’facies associations’’.

### Organize recurring, representative, and diagnostic facies attributes into '''facies associations'''.

### Identify and describe ‘’stratal packages and key surfaces’’ (sequence boundaries and flooding surfaces; [[:file:M126CH03-Figure3.jpeg|Figure 3]]; Tables 7, 11). Obtain a spectral gamma-ray profile to further characterize stratigraphic units ([[:file:M126CH03-Figure4.jpeg|Figure 4]]).

### Identify and describe '''stratal packages and key surfaces''' (sequence boundaries and flooding surfaces; [[:file:M126CH03-Figure3.jpeg|Figure 3]]; Tables 7, 11). Obtain a spectral gamma-ray profile to further characterize stratigraphic units ([[:file:M126CH03-Figure4.jpeg|Figure 4]]).

### Record all information consistently in an appropriate format, designed for your particular setting or unit.

### Record all information consistently in an appropriate format, designed for your particular setting or unit.

# ‘’Make interpretations’’

# '''Make interpretations'''

## ‘’Integrate’’ outcrop, core, or thin-section observations with analytical, well-log, and seismic data as available. Make a hierarchical interpretation of stratal units (laminae, laminasets, beds, bedsets, parasequences, parasequence sets, sequences; significant stratal boundaries).

## '''Integrate''' outcrop, core, or thin-section observations with analytical, well-log, and seismic data as available. Make a hierarchical interpretation of stratal units (laminae, laminasets, beds, bedsets, parasequences, parasequence sets, sequences; significant stratal boundaries).

## ‘’Make interpretations’’ of dominant sediment provenance, input mode, physical reworking, sediment accumulation rate, completeness of sedimentary record, bottom-water redox conditions, and environment of deposition<ref name=Bhcsea2005 /><ref name=Bhcsea2014 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /> (e.g., [[:file:M126Ch3-Table2|Table 2]] ; see also [[Laminasets, beds, and bedsets]], [[Parasequences]], and [[Parasequence sets and depositional sequences]]).

## '''Make interpretations''' of dominant sediment provenance, input mode, physical reworking, sediment accumulation rate, completeness of sedimentary record, bottom-water redox conditions, and environment of deposition<ref name=Bhcsea2005 /><ref name=Bhcsea2014 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /> (e.g., [[:file:M126Ch3-Table2|Table 2]] ; see also [[Laminasets, beds, and bedsets]], [[Parasequences]], and [[Parasequence sets and depositional sequences]]).

[[file:M126Ch3-Table10.jpeg|thumb|300px|’’Table 10.’’ Scratch Test (After Lazar et al.<ref name=Lzrea2015a /><ref name=Lzrea2015b />).]]

[[file:M126Ch3-Table10.jpeg|thumb|300px|'''Table 10.''' Scratch Test (After Lazar et al.<ref name=Lzrea2015a /><ref name=Lzrea2015b />).]]

[[file:M126Ch3-Figure3.jpeg|thumb|300px|{{figure number|3}}Accommodation succession showing key stratigraphic surfaces, stacking patterns, and depositional sequence expression using definitions outlined in [[:file:M126CH03-Table7.jpeg|Tables 7]] and [[:file:M126Ch3-Table11.jpeg|11]]<ref name=Abrea2010 /> (after Neal and Abreu<ref name=NlABr>Neal, J., and V. Abreu, 2009, Sequence stratigraphy hierarchy and the accommodation succession method: Geology, v. 37, p. 779–782.</ref>, and Abreu et al.<ref name=Abrea2014>Abreu, V., K. Pederson, J. Neal, and K. M. Bohacs, 2014, A simplified guide for sequence stratigraphy: Nomenclature, definitions and method: Geological Society of America Annual Meeting, 19–22 October 2014, Vancouver, British Columbia, Abstracts with Programs, v. 46, no. 6, p. 832.</ref>).]]

[[file:M126Ch3-Figure3.jpeg|thumb|300px|{{figure number|3}}Accommodation succession showing key stratigraphic surfaces, stacking patterns, and depositional sequence expression using definitions outlined in [[:file:M126CH03-Table7.jpeg|Tables 7]] and [[:file:M126Ch3-Table11.jpeg|11]]<ref name=Abrea2010 /> (after Neal and Abreu<ref name=NlABr>Neal, J., and V. Abreu, 2009, Sequence stratigraphy hierarchy and the accommodation succession method: Geology, v. 37, p. 779–782.</ref>, and Abreu et al.<ref name=Abrea2014>Abreu, V., K. Pederson, J. Neal, and K. M. Bohacs, 2014, A simplified guide for sequence stratigraphy: Nomenclature, definitions and method: Geological Society of America Annual Meeting, 19–22 October 2014, Vancouver, British Columbia, Abstracts with Programs, v. 46, no. 6, p. 832.</ref>).]]