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Standardizing texture and facies codes for A process-based classification of clastic sediment and rock

Kathleen M. Farrell, W. Burleigh Harris, David J. Mallinson, Stephen J. Culver, Stanley R. Riggs, Jessica Pierson, Jean M. Self-Trail and Jeff C. Lautier
Standardizing texture and facies codes for A process-based classification of clastic sediment and rock
Journal of Sedimentary Research (June 2012) 82 (6): 364-378


Proposed here is a universally applicable, texturally based classification of clastic sediment that is independent from composition, cementation, and geologic environment, is closely allied to process sedimentology, and applies to all compartments in the source-to-sink system. The classification is contingent on defining the term "clastic" so that it is independent from composition or origin and includes any particles or grains that are subject to erosion, transportation, and deposition. Modifications to Folk's (1980) texturally based classification that include applying new assumptions and defining a broader array of textural fields are proposed to accommodate this. The revised ternary diagrams include additional textural fields that better define poorly sorted and coarse-grained deposits, so that all end members (gravel, sand, and mud size fractions) are included in textural codes. Revised textural fields, or classes, are based on a strict adherence to volumetric estimates of percentages of gravel, sand, and mud size grain populations, which by definition must sum to 100%. The new classification ensures that descriptors are applied consistently to all end members in the ternary diagram (gravel, sand, and mud) according to several rules, and that none of the end members are ignored. These modifications provide bases for standardizing vertical displays of texture in graphic logs, lithofacies codes, and their derivatives--hydrofacies. Hydrofacies codes are nondirectional permeability indicators that predict aquifer or reservoir potential. Folk's (1980) ternary diagram for fine-grained clastic sediments (sand, silt, and clay size fractions) is also revised to preserve consistency with the revised diagram for gravel, sand, and mud. Standardizing texture ensures that the principles of process sedimentology are consistently applied to compositionally variable rock sequences, such as mixed carbonate-siliciclastic ramp settings, and the extreme ends of depositional systems.

ISSN: 1527-1404
EISSN: 1938-3681
Serial Title: Journal of Sedimentary Research
Serial Volume: 82
Serial Issue: 6
Title: Standardizing texture and facies codes for A process-based classification of clastic sediment and rock
Affiliation: North Carolina Geological Survey, Raleigh Field Office and Core Repository, Raleigh, NC, United States
Pages: 364-378
Published: 201206
Text Language: English
Publisher: Society for Sedimentary Geology, Tulsa, OK, United States
References: 40
Accession Number: 2012-073163
Categories: Sedimentary petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 plate, charts
Secondary Affiliation: University of North Carolina Wilmington, USA, United StatesEast Carolina University, USA, United StatesU. S. Geological Survey, USA, United StatesNorth Carolina Division of Water Resources, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States
Update Code: 201238
Program Name: USGSOPNon-USGS publications with USGS authors
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