Changes

[[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:M126CH03-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:M126CH03-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-Table11.jpeg|thumb|300px|’’Table 11.’’ Definitions of Systems Tracts With Stacking Patterns and Recognition Criteria (after Abreu et al.<ref name=Abrea2014 />).]]

[[file:M126Ch3-Table11.jpeg|thumb|300px|'''Table 11.''' Definitions of Systems Tracts With Stacking Patterns and Recognition Criteria (after Abreu et al.<ref name=Abrea2014 />).]]

[[file:M126CH03-Figure4.jpeg|thumb|300px|{{figure number|4}}Schematic diagram of using a gamma-ray spectrometer in the field (after Schwalbach and Bohacs<ref name=SchwlbchBhcs1992 /><ref>Schwalbach, J. R., and K. M. Bohacs, 1995, Stratigraphic sections and gamma-ray spectrometry from five outcrops of the Monterey Formation in southwestern California; Naples Beach, Point Pedernales, Lion’s Head, Shell Beach, and Point Buchon: US Geological Survey Bulletin 1995, p. Q1–Q39.</ref>).]]

[[file:M126CH03-Figure4.jpeg|thumb|300px|{{figure number|4}}Schematic diagram of using a gamma-ray spectrometer in the field (after Schwalbach and Bohacs<ref name=SchwlbchBhcs1992 /><ref>Schwalbach, J. R., and K. M. Bohacs, 1995, Stratigraphic sections and gamma-ray spectrometry from five outcrops of the Monterey Formation in southwestern California; Naples Beach, Point Pedernales, Lion’s Head, Shell Beach, and Point Buchon: US Geological Survey Bulletin 1995, p. Q1–Q39.</ref>).]]

====Key Concepts of Sequence Stratigraphy====

====Key Concepts of Sequence Stratigraphy====

Sequence stratigraphy is the study of rocks within a framework in which the vertical succession of rocks is subdivided into genetically related 3-D units that have characteristic stacking patterns and physical, biogenic, and chemical properties, and are bounded by surfaces, including unconformities and their correlative conformities<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Abrea2010 /><ref name=MtchmVl1977 /><ref name=Vl1975 /><ref name=Vl1977a /><ref name=Vl1977b /><ref name=Vl1977c /><ref name=Vlea1991 /><ref name=Mtchm1977>Mitchum Jr., R. M., 1977, Seismic stratigraphy and global changes of sea level, Part 11: Glossary of terms used in seismic stratigraphy, in C. E. Payton, ed., Seismic stratigraphy—Applications to hydrocarbon exploration: AAPG Memoir 26, p. 205–212.</ref><ref name=Psmntr1988>Posamentier, H. W., M. T. Jervey, and P. R. Vail, 1988, Eustatic controls on clastic deposition. I. Conceptual framework, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes-an integrated approach: SEPM Special Publication 42, p. 110–124.</ref><ref name=VnWgnres1988>Van Wagoner, J. C., H. W. Posamentier, R. M. Mitchum, P. R. Vail, P. R., J. F. Sarg, T. S. Loutit, and J. Hardenbol, 1988, An overview of sequence stratigraphy and key definitions, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes—an integrated approach: SEPM Special Publication 42, p. 39–45.</ref>. Sequence stratigraphy has five major components<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Abrea2010 />:

Sequence stratigraphy is the study of rocks within a framework in which the vertical succession of rocks is subdivided into genetically related 3-D units that have characteristic stacking patterns and physical, biogenic, and chemical properties, and are bounded by surfaces, including unconformities and their correlative conformities<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Abrea2010 /><ref name=MtchmVl1977 /><ref name=Vl1975 /><ref name=Vl1977a /><ref name=Vl1977b /><ref name=Vl1977c /><ref name=Vlea1991 /><ref name=Mtchm1977>Mitchum Jr., R. M., 1977, Seismic stratigraphy and global changes of sea level, Part 11: Glossary of terms used in seismic stratigraphy, in C. E. Payton, ed., Seismic stratigraphy—Applications to hydrocarbon exploration: AAPG Memoir 26, p. 205–212.</ref><ref name=Psmntr1988>Posamentier, H. W., M. T. Jervey, and P. R. Vail, 1988, Eustatic controls on clastic deposition. I. Conceptual framework, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes-an integrated approach: SEPM Special Publication 42, p. 110–124.</ref><ref name=VnWgnres1988>Van Wagoner, J. C., H. W. Posamentier, R. M. Mitchum, P. R. Vail, P. R., J. F. Sarg, T. S. Loutit, and J. Hardenbol, 1988, An overview of sequence stratigraphy and key definitions, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes—an integrated approach: SEPM Special Publication 42, p. 39–45.</ref>. Sequence stratigraphy has five major components<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Abrea2010 />:

* ‘’Method’’ that recognizes a hierarchy of various types of stratal surfaces, rock packages, and stacking patterns.

* '''Method''' that recognizes a hierarchy of various types of stratal surfaces, rock packages, and stacking patterns.

* ‘’Observations’’ of physical, biological, and chemical aspects of surfaces and rocks within a 3-D framework.

* '''Observations''' of physical, biological, and chemical aspects of surfaces and rocks within a 3-D framework.

* ‘’Models’’ that summarize and generalize detailed observations.

* '''Models''' that summarize and generalize detailed observations.

* ‘’Mechanisms’’ that seek to explain the origin of stratal patterns and facies distributions in terms of small-to-large-scale processes and to provide predictive capabilities.

* '''Mechanisms''' that seek to explain the origin of stratal patterns and facies distributions in terms of small-to-large-scale processes and to provide predictive capabilities.

* ‘’Prediction and Testing’’ that uses further observations to test predictive capabilities, refine models, and enhance the understanding of key mechanisms.

* '''Prediction and Testing''' that uses further observations to test predictive capabilities, refine models, and enhance the understanding of key mechanisms.

Sequence stratigraphy allows the construction of a comprehensive stratigraphic framework based on a single criterion—the physical relations of the strata themselves—that reveals genetically related rocks. Additionally, a comprehensive sequence-stratigraphic framework is ideal for integrating all types of data, from reflection seismic, through well-log, core, outcrop, thin section, to organic and inorganic geochemistry. This integrated response allows recognition, correlation, and prediction of sequence-stratigraphic units and surfaces in all these datasets across all scales.

Sequence stratigraphy allows the construction of a comprehensive stratigraphic framework based on a single criterion—the physical relations of the strata themselves—that reveals genetically related rocks. Additionally, a comprehensive sequence-stratigraphic framework is ideal for integrating all types of data, from reflection seismic, through well-log, core, outcrop, thin section, to organic and inorganic geochemistry. This integrated response allows recognition, correlation, and prediction of sequence-stratigraphic units and surfaces in all these datasets across all scales.

Stratal Units—Sequence-stratigraphic stratal units are defined using geometric criteria, with the supporting evidence of other physical, biogenic, and chemical attributes. Although thickness, areal extent, and time for formation are neither essential attributes nor part of the definition of sequence-stratigraphic units, these units do tend to have characteristic spatial and temporal scales as well as common modes of formation. Note that characteristic thicknesses tend to be a function of grain size and are typically thinner in mudstones. Characteristic timescales tend to be strongly related to depositional setting and basin size, with relatively short intervals in small lacustrine basins and relatively long intervals in large marine basins (according to the response time of the basin, which scales to the second power of its characteristic length scale; see Paola et al.<ref>Paola, C., P. L. Heller, P. L., and C. L. Angevine, 1992, The large-scale dynamics of grain-size variation in alluvial basins, 1: Theory: Basin Research, v. 4, p. 73–90.</ref>).

Stratal Units—Sequence-stratigraphic stratal units are defined using geometric criteria, with the supporting evidence of other physical, biogenic, and chemical attributes. Although thickness, areal extent, and time for formation are neither essential attributes nor part of the definition of sequence-stratigraphic units, these units do tend to have characteristic spatial and temporal scales as well as common modes of formation. Note that characteristic thicknesses tend to be a function of grain size and are typically thinner in mudstones. Characteristic timescales tend to be strongly related to depositional setting and basin size, with relatively short intervals in small lacustrine basins and relatively long intervals in large marine basins (according to the response time of the basin, which scales to the second power of its characteristic length scale; see Paola et al.<ref>Paola, C., P. L. Heller, P. L., and C. L. Angevine, 1992, The large-scale dynamics of grain-size variation in alluvial basins, 1: Theory: Basin Research, v. 4, p. 73–90.</ref>).

The ‘’depositional sequence’’ is the fundamental unit of sequence stratigraphy; it is a relatively conformable succession of strata bounded at base and top by laterally extensive (regional scale) unconformities and their correlative conformities<ref name=Abrea2010 /><ref name=NlABr /><ref name=Mtchm1977 /> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]). Depositional sequences are meters to hundreds of meters thick and extend over many thousands of square kilometers. They are inferred to represent multiple episodes of shoreline progradation with significant shifts in coastal onlap and base level over tens to thousands of millennia. A complete depositional sequence can be subdivided into ‘’systems tracts’’ defined by their position within the sequence and by the stacking patterns of the ‘’parasequence sets’’ within each systems tract. Parasequence sets are bounded by ‘’parasequence set boundaries’’ that are ‘’flooding surfaces’’ and their equivalents. Systems tracts include lowstand, trans-gressive, and highstand (see [[:file:M126Ch3-Table11.jpeg|Table 11]]).

The '''depositional sequence''' is the fundamental unit of sequence stratigraphy; it is a relatively conformable succession of strata bounded at base and top by laterally extensive (regional scale) unconformities and their correlative conformities<ref name=Abrea2010 /><ref name=NlABr /><ref name=Mtchm1977 /> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]). Depositional sequences are meters to hundreds of meters thick and extend over many thousands of square kilometers. They are inferred to represent multiple episodes of shoreline progradation with significant shifts in coastal onlap and base level over tens to thousands of millennia. A complete depositional sequence can be subdivided into '''systems tracts''' defined by their position within the sequence and by the stacking patterns of the '''parasequence sets''' within each systems tract. Parasequence sets are bounded by '''parasequence set boundaries''' that are '''flooding surfaces''' and their equivalents. Systems tracts include lowstand, trans-gressive, and highstand (see [[:file:M126Ch3-Table11.jpeg|Table 11]]).

A ‘’parasequence’’, the main building block of the depositional sequence, is a relatively conformable succession of beds or bedsets bounded below and above by parasequence boundaries (surfaces that record a pause in sediment accumulation, formed by nondeposition, local erosion, or very slow sedimentation and include flooding, abandonment, or reactivation surfaces and their correlative surfaces; after Van Wagoner et al.<ref name=VnWgnrea1990 /><ref name=VnWgnres1988 />; Bohacs<ref name=Bhcs1998 />, Bohacs et al.<ref name=Bhcsea2014 />). Parasequences range from tens of centimeters to tens of meters in thickness and extend over significant parts of a basin, on the order of hundreds to thousands of square kilometers. In shelf or lacustrine settings, they typically represent one episode of shoreline or mudbelt progradation—the dominant depositional “motif” or building block. Equivalent-scale units in other settings include fan “lobes” in submarine-fan settings and channel-belt sets in fluvial or submarine-slope settings. Parasequences are interpreted to form in centuries to millennia.

A '''parasequence''', the main building block of the depositional sequence, is a relatively conformable succession of beds or bedsets bounded below and above by parasequence boundaries (surfaces that record a pause in sediment accumulation, formed by nondeposition, local erosion, or very slow sedimentation and include flooding, abandonment, or reactivation surfaces and their correlative surfaces; after Van Wagoner et al.<ref name=VnWgnrea1990 /><ref name=VnWgnres1988 />; Bohacs<ref name=Bhcs1998 />, Bohacs et al.<ref name=Bhcsea2014 />). Parasequences range from tens of centimeters to tens of meters in thickness and extend over significant parts of a basin, on the order of hundreds to thousands of square kilometers. In shelf or lacustrine settings, they typically represent one episode of shoreline or mudbelt progradation—the dominant depositional “motif” or building block. Equivalent-scale units in other settings include fan “lobes” in submarine-fan settings and channel-belt sets in fluvial or submarine-slope settings. Parasequences are interpreted to form in centuries to millennia.

A ‘’bed’’ is a relatively conformable succession of genetically related laminae or laminasets bounded at base and top by bedding surfaces—surfaces of erosion, nondeposition, or correlative conformity<ref name=Cmpbll1967 />.

A '''bed''' is a relatively conformable succession of genetically related laminae or laminasets bounded at base and top by bedding surfaces—surfaces of erosion, nondeposition, or correlative conformity<ref name=Cmpbll1967 />.

A ‘’lamina’’ is the smallest megascopic layer in a sedimentary succession without internal layers<ref name=Cmpbll1967 /> (typically ≥0.1 mm or so). See [[Mudstone nomenclature]], and [[Laminasets, beds, and bedsets]] for detailed discussions of laminae, beds, and parasequences.

A '''lamina''' is the smallest megascopic layer in a sedimentary succession without internal layers<ref name=Cmpbll1967 /> (typically ≥0.1 mm or so). See [[Mudstone nomenclature]], and [[Laminasets, beds, and bedsets]] for detailed discussions of laminae, beds, and parasequences.

=====Stratal Surfaces=====

=====Stratal Surfaces=====

The two distinct types of widespread and mappable surfaces are parasequence boundaries and sequence boundaries<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=MtchmVl1977 /><ref name=Vl1975 /><ref name=Vl1977a /><ref name=Vlea1991 /><ref name=Psmntr1988 /><ref name=VnWgnres1988 /><ref name=Bhcsea2004>Bohacs, K. M., G. J. Grabowski Jr., and J. E. Neal, 2004, Unlocking geological history: The key roles of mudstones and sequence stratigraphy, in J. Schieber, and O. R. Lazar, eds., Devonian black shales of the Eastern US: New insights into sedimentology and stratigraphy from the subsurface and outcrops in the Illinois and Appalachian basins: Indiana Geological Survey Open File Study 04-05, p. 78.</ref> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]). Identification of these surfaces in a stratal succession relies on both their local character and their lateral extent<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=Lzr2007 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /><ref name=Abrea2010 /><ref name=VnWgnrea1990 /><ref name=Bhcsea2004 />.

The two distinct types of widespread and mappable surfaces are parasequence boundaries and sequence boundaries<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=MtchmVl1977 /><ref name=Vl1975 /><ref name=Vl1977a /><ref name=Vlea1991 /><ref name=Psmntr1988 /><ref name=VnWgnres1988 /><ref name=Bhcsea2004>Bohacs, K. M., G. J. Grabowski Jr., and J. E. Neal, 2004, Unlocking geological history: The key roles of mudstones and sequence stratigraphy, in J. Schieber, and O. R. Lazar, eds., Devonian black shales of the Eastern US: New insights into sedimentology and stratigraphy from the subsurface and outcrops in the Illinois and Appalachian basins: Indiana Geological Survey Open File Study 04-05, p. 78.</ref> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]). Identification of these surfaces in a stratal succession relies on both their local character and their lateral extent<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=Lzr2007 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /><ref name=Abrea2010 /><ref name=VnWgnrea1990 /><ref name=Bhcsea2004 />.

A ‘’parasequence boundary’’ (‘’flooding surface’’ and correlative surfaces) records a supercritical increase in accommodation relative to sediment supply that significantly changes system behavior<ref name=Bhcs1998 /><ref name=Bhcsea2004 />. Commonly, strata above a parasequence boundary are deposited in deeper water, and less energetic and more distal environments, whereas strata below a flooding surface are deposited in shallower water, and more energetic and proximal environments<ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /><ref name=Bhcsea2004 />. Parasequence boundaries are marked by a sharp decrease in coarse sediment supply, increased and laterally extensive accumulation of pelagic and authigenic components (e.g., organic matter, remains of plankton and nekton, volcanic ash, dropstones; cements, nodules, and concretions), early lithification or cementation, and increased continuity of laminae, beds, and bedsets<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=McqkrTlr1996 /><ref name=Bhcs1990><ref name=Bhcsea2004 />. See [[Parasequences]] for a full discussion.

A '''parasequence boundary''' ('''flooding surface''' and correlative surfaces) records a supercritical increase in accommodation relative to sediment supply that significantly changes system behavior<ref name=Bhcs1998 /><ref name=Bhcsea2004 />. Commonly, strata above a parasequence boundary are deposited in deeper water, and less energetic and more distal environments, whereas strata below a flooding surface are deposited in shallower water, and more energetic and proximal environments<ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=Lzrea2015a /><ref name=Lzrea2015b /><ref name=Bhcsea2004 />. Parasequence boundaries are marked by a sharp decrease in coarse sediment supply, increased and laterally extensive accumulation of pelagic and authigenic components (e.g., organic matter, remains of plankton and nekton, volcanic ash, dropstones; cements, nodules, and concretions), early lithification or cementation, and increased continuity of laminae, beds, and bedsets<ref name=BhcSchwlbch1992 /><ref name=Bhcs1998 /><ref name=Bhcsea2014 /><ref name=McqkrTlr1996 /><ref name=Bhcs1990><ref name=Bhcsea2004 />. See [[Parasequences]] for a full discussion.

Within each depositional sequence, two specific parasequence boundaries are interpreted as lower order surfaces, one as the transgressive surface (TS) and another as the maximum flooding surface (MFS), based on their position and geometric relations<ref name=Bhcs22c /> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]).

Within each depositional sequence, two specific parasequence boundaries are interpreted as lower order surfaces, one as the transgressive surface (TS) and another as the maximum flooding surface (MFS), based on their position and geometric relations<ref name=Bhcs22c /> ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]).

The ‘’transgressive surface’’ is the parasequence boundary atop the most basinward position of the shoreline of the progradational-aggradational (PA) or lowstand systems tract. It defines the top of the lowstand systems tract and separates progradationally to aggradationally (stepping basinward) stacked parasequences below from retrogradationally (stepping landward) stacked parasequences above (after Bohacs and Schwalbach<ref name=BhcSchwlbch1992 />, Bohacs<ref name=Bhcs1998 />). It is also known as the maximum regressive surface (MRS) <ref name=Abrea2014 />. The surface is interpreted beneath the first landward shift (backstep) of the shelf–slope break; in vertical successions, at the turn-around in parasequence stacking pattern from progradation or aggradation to retrogradation.

The '''transgressive surface''' is the parasequence boundary atop the most basinward position of the shoreline of the progradational-aggradational (PA) or lowstand systems tract. It defines the top of the lowstand systems tract and separates progradationally to aggradationally (stepping basinward) stacked parasequences below from retrogradationally (stepping landward) stacked parasequences above (after Bohacs and Schwalbach<ref name=BhcSchwlbch1992 />, Bohacs<ref name=Bhcs1998 />). It is also known as the maximum regressive surface (MRS) <ref name=Abrea2014 />. The surface is interpreted beneath the first landward shift (backstep) of the shelf–slope break; in vertical successions, at the turn-around in parasequence stacking pattern from progradation or aggradation to retrogradation.

A ‘’maximum flooding surface’’ is the one particular parasequence boundary representing the maximum landward extent of basinal facies within a sequence. It defines the top of the transgressive systems tract and separates retrogradationally (stepping landward) stacked parasequences below from aggradationally to progradationally (stepping basinward) stacked parasequences above (after Bohacs and Schwalbach<ref name=BhcSchwlbch1992 />, Bohacs<ref name=Bhcs1998 />). It is also known as the maximum transgressive surface (MTS)<ref name=Abrea2014 />. The presence of prograding strata above identifies the maximum flooding surface as a downlap surface on reflection seismic profiles. It represents the greatest landward extent of the sea or lake within a depositional sequence<ref name=BhcSchwlbch1992 /><ref name=Lttitea1988><ref>Posamentier, H. W., and P. R. Vail, 1988, Eustatic controls on clastic deposition II—sequence and systems tract models, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes-an integrated approach: SEPM Special Publication 42, p. 125–154</ref>.

A '''maximum flooding surface''' is the one particular parasequence boundary representing the maximum landward extent of basinal facies within a sequence. It defines the top of the transgressive systems tract and separates retrogradationally (stepping landward) stacked parasequences below from aggradationally to progradationally (stepping basinward) stacked parasequences above (after Bohacs and Schwalbach<ref name=BhcSchwlbch1992 />, Bohacs<ref name=Bhcs1998 />). It is also known as the maximum transgressive surface (MTS)<ref name=Abrea2014 />. The presence of prograding strata above identifies the maximum flooding surface as a downlap surface on reflection seismic profiles. It represents the greatest landward extent of the sea or lake within a depositional sequence<ref name=BhcSchwlbch1992 /><ref name=Lttitea1988><ref>Posamentier, H. W., and P. R. Vail, 1988, Eustatic controls on clastic deposition II—sequence and systems tract models, in C. K. Wilgus, B. S. Hastings, C. G. St. C. Kendall, H. W. Posamentier, C. A. Ross, and J. C. Van Wagoner, eds., Sea level changes-an integrated approach: SEPM Special Publication 42, p. 125–154</ref>.

‘’Sequence boundaries’’ are the laterally extensive (regional scale) unconformities and correlative conformities that bound a depositional sequence<ref name=Mtchm1977 />; they are fundamentally different from flooding surfaces. Sequence boundaries (in contrast to flooding surfaces) record a supercritical decrease in accommodation relative to sediment supply, commonly accompanied by an increase in depositional energy or a significant change in sediment supply (e.g., erosional bypass in marine environments), over hundreds to thousands of square kilometers<ref name=Bhcs1998 /><ref name=Lzr2007 /><ref name=Bhcsea2004 /><ref name=BhcsLzr2008>Bohacs, K. M., and O. R. Lazar, 2008, The role of sequence stratigraphy in unraveling and applying the complex controls from mudstone reservoir properties: AAPG Search and Discovery article #90078.</ref><ref>Bohacs, K. M., and O. R. Lazar, 2010, Sequence stratigraphy in fine-grained rocks, in J. Schieber, O. R. Lazar, and K. M. Bohacs, eds., Sedimentology and stratigraphy of shales: Expression and correlation of depositional sequences in the Devonian of Tennessee, Kentucky, and Indiana: SEPM Field Trip Guidebook, p. 15–30.</ref>. They are easiest to recognize in medial reaches of the shelf. Common attributes of sequence boundaries are summarized in [[:file:M126Ch3-Table7.jpeg|Table 7]] and discussed further in [[Parasequence sets and depositional sequences]]. Sequence boundaries are surfaces across which there is a basinward shift in coastal onlap, marked by laterally extensive erosional truncation of underlying strata (with evidence of exposure and presence of reworked clastics in lag deposits) and toplap below and onlap and downlap above<ref name=Bhcs1998 /><ref name=Schbr1998a /><ref name=Lzr2007 /><ref name=SchwlbchBhcs1992 /><ref name=Mtchm1977 /><ref name=Bhcsea2004 /><ref name=BhcsLzr2008 />. It occurs below the abrupt basinward shift in shoreline position at the base of a depositional sequence. It is placed at the surface beneath the first increase in accommodation above progradationally or degradationally stacked parasequences, at the break in shoreline sandstone trajectory ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]).

'''Sequence boundaries''' are the laterally extensive (regional scale) unconformities and correlative conformities that bound a depositional sequence<ref name=Mtchm1977 />; they are fundamentally different from flooding surfaces. Sequence boundaries (in contrast to flooding surfaces) record a supercritical decrease in accommodation relative to sediment supply, commonly accompanied by an increase in depositional energy or a significant change in sediment supply (e.g., erosional bypass in marine environments), over hundreds to thousands of square kilometers<ref name=Bhcs1998 /><ref name=Lzr2007 /><ref name=Bhcsea2004 /><ref name=BhcsLzr2008>Bohacs, K. M., and O. R. Lazar, 2008, The role of sequence stratigraphy in unraveling and applying the complex controls from mudstone reservoir properties: AAPG Search and Discovery article #90078.</ref><ref>Bohacs, K. M., and O. R. Lazar, 2010, Sequence stratigraphy in fine-grained rocks, in J. Schieber, O. R. Lazar, and K. M. Bohacs, eds., Sedimentology and stratigraphy of shales: Expression and correlation of depositional sequences in the Devonian of Tennessee, Kentucky, and Indiana: SEPM Field Trip Guidebook, p. 15–30.</ref>. They are easiest to recognize in medial reaches of the shelf. Common attributes of sequence boundaries are summarized in [[:file:M126Ch3-Table7.jpeg|Table 7]] and discussed further in [[Parasequence sets and depositional sequences]]. Sequence boundaries are surfaces across which there is a basinward shift in coastal onlap, marked by laterally extensive erosional truncation of underlying strata (with evidence of exposure and presence of reworked clastics in lag deposits) and toplap below and onlap and downlap above<ref name=Bhcs1998 /><ref name=Schbr1998a /><ref name=Lzr2007 /><ref name=SchwlbchBhcs1992 /><ref name=Mtchm1977 /><ref name=Bhcsea2004 /><ref name=BhcsLzr2008 />. It occurs below the abrupt basinward shift in shoreline position at the base of a depositional sequence. It is placed at the surface beneath the first increase in accommodation above progradationally or degradationally stacked parasequences, at the break in shoreline sandstone trajectory ([[:file:M126Ch3-Figure3.jpeg|Figure 3]]).

====Constructing and Testing a Sequence-Stratigraphic Framework for Mudstones====

====Constructing and Testing a Sequence-Stratigraphic Framework for Mudstones====