Sequence Stratigraphy Framework for “Conceptual Models” Used to Interpret Depositional Systems - beauty but not truth? Christopher G.
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Sequence Stratigraphy
Framework for “ Conceptual Models ” Used to Interpret Depositional Systems
beauty but not truth
?
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Christopher G. St. C. Kendall University of South Carolina [email protected] 803 978 7523
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Sequence Stratigraphy
A framework of genetically related stratigraphic facies geometries and their bounding surfaces used to determine depositional setting Establish Setting
Sequence Stratigraphy Defined
Sequence Stratigraphy – Terminology Stratigraphers’ position on terminology similar to Humpty Dumpty's from Lewis Carroll’s “Through the Looking Glass ” “When I use a word, it means just what I choose it to mean nothing more nor less”.
Sequence Stratigraphy Defined
Why provide ‘rules’ for sequence stratigraphic nomenclature?
We use common terms and know their meaning Have a standard hierarchy of subdivisions Have a uniform methodology Guidance for revision Teaching resource : each new generation of pupils & practitioners have a common understanding
Sequence Stratigraphy Defined
Sequence Stratigraphy – Terminology After all “eggs” are all “eggs”…..
Sequence Stratigraphy Defined
Sequence Stratigraphy – Terminology Perspective of precedence &/or copyright?
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Sequence Stratigraphy
– The process
Interpretation of the Sedimentary section involves: From oldest to youngest, identify the subdividing that envelope & enclose the discrete geometric bodies of sediment of the sedimentary section & build a surfaces template Backstrip these geometries & then use the template surfaces to reassemble of them in order of their accumulation The subdividing surfaces, geometry, lithofacies & fauna are input to a conceptual model to determine the evolving character of the depositional setting ‘‘Each stratal unit is defined and identified only by physical relationships of the strata, including lateral continuity and geometry of the surfaces bounding the units, vertical stacking patterns, and lateral geometry of the strata within the units." (Van Wagoner et al., 1990).
Sequence Stratigraphy Defined
'Depositional' sequence Vail et al 1971
Sequence Stratigraphy Defined
SB mfs TS
Establish a framework of genetically related stratigraphic facies geometries and their bounding surfaces to determine depositional setting
Sequence Stratigraphy Defined
Sequence Stratigraphy Defined
Coast Types
Clastic Depositional Systems
Sequence Stratigraphy Defined
Clastic Depositional Systems
Sequence Stratigraphy Defined
Clastic Depositional Systems
Sequence Stratigraphy Defined
Clastic Depositional Systems MOVIE TIME!!!!!
Sequence Stratigraphy Defined
Sedimentary Analysis Potential flow of interpretation data data Scheme used to characterize depositional systems so they can be compared interpretation interpretation interpretation
Sequence Stratigraphy Defined
Power of Sequence Stratigraphy
Determines depositional setting by: Establishing the order in which strata were laid down in Explains the the elements geometric hierarchy formed by the strata of sedimentary strata & Uses the major surfaces marking breaks in the character of sedimentary section as a template for conceptual depositional models , independent of time (relative ages) Geologic time derived from: Radiometric markers Biostratigraphic markers
Sequence Stratigraphy Defined
Sedimentary Fill Hierarchy
Jeroen Schokker, Wim Westerhoff & Henk Weerts after Heinz & Aigner, 2003
Sequence Stratigraphy Defined
Building Block Sedimentary Fill Hierarchy Sediment body characterization in order of decreasing complexity Complex Set Complex Story Element Bed These are the fundamental components of Sequences and System tracts
Sequence Stratigraphy Defined
Sequence Stratigraphy Defined
Bedding Planes
Sequence Stratigraphy Defined
Hierarchy of Carbonate Shelf Architectural Elements
COMPONENT GRAINS & DIAGENESIS BED, LITHOLOGY BEDS STACKED CYCLES OF BEDS STACKED BED CYCLES PROGRADING MARGIN HST MARGIN COMPLEX SHELF MARGIN COMPLEX MARGIN COMPLEX ONLAPPING MARGIN
Sequence Stratigraphy Defined
PROGRADING MARGIN SHELF COMPLEX
Fluvial - Architectural Elements
Sequence Stratigraphy Defined
Deepwater - Architectural Elements
Sequence Stratigraphy Defined
Deepwater - Architectural Elements
Sequence Stratigraphy Defined
Deepwater - Architectural Elements
Sequence Stratigraphy Defined
Elements – Sequence Building Blocks
Definition of element hierarchy Framework for systematic description & comparison of deposits of a depositional setting (reef, carbonate shelf, fluvial, deltaic, deepwater etc) Based on physical organization of strata (geometry) & the surfaces bounding them Genetically-related stratigraphic elements form the hierarchy Independent of type of setting Applicable at all scales & to all sedimentary systems Purpose Analysis & comparison of the elements of similar depositional systems Provide the detailed character of a sequence and/or system tract Net to-gross, aspect ratio, & connectivity Lithofacies type & aquifer/reservoir quality Application Better defined depositional geometries and so depositional models More accurate aquifer/resource assessment Optimize strategy for depletion of aquifer/resource
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
History of Sequence Stratigraphy
Sloss recognized intercontinental unconformities them to eustasy & related Vail extrapolated eustatic signals to seismic sequence boundaries Jervey’s simulations showed seismic sequences product of cyclic sea level (base level) change Van Wagoner & Posamentier related unconformities, transgressive surfaces & maximum flooding surfaces to boundaries of system tracts in depositional sequences responding to sea level change Hydrocarbon exploration models & production reservoir models use bounding surfaces, facies assemblages & system tracts as templates for depositional models & lithofacies geometry predictions
Sequence Stratigraphy Defined
Sloss Unconformities & Eustasy
Sequence Stratigraphy Defined
After Lowell Thwaite
History of Sequence Stratigraphy
Sloss recognized intercontinental unconformities them to eustasy & related Vail extrapolated eustatic signals to seismic sequence boundaries Jervey’s simulations showed seismic sequences product of cyclic sea level (base level) change Van Wagoner & Posamentier related unconformities, transgressive surfaces & maximum flooding surfaces to boundaries of system tracts in depositional sequences responding to sea level change Hydrocarbon exploration models & production reservoir models use bounding surfaces, facies assemblages & system tracts as templates for depositional models & lithofacies geometry predictions
Sequence Stratigraphy Defined
1st Seismic Sequence Interpretation
Vail et al, 1976 Mesozoic through Tertiary of Offshore Morocco
Sequence Stratigraphy Defined
History of Sequence Stratigraphy
Sloss recognized intercontinental unconformities them to eustasy & related Vail extrapolated eustatic signals to seismic sequence boundaries Jervey’s simulations showed seismic sequences product of cyclic sea level (base level) change Van Wagoner & Posamentier related unconformities, transgressive surfaces & maximum flooding surfaces to boundaries of system tracts in depositional sequences responding to sea level change Hydrocarbon exploration models & production reservoir models use bounding surfaces, facies assemblages & system tracts as templates for depositional models & lithofacies geometry predictions
Sequence Stratigraphy Defined
History of Sequence Stratigraphy
Sloss recognized intercontinental unconformities them to eustasy & related Vail extrapolated eustatic signals to seismic sequence boundaries Jervey’s simulations showed seismic sequences product of cyclic sea level (base level) change Van Wagoner & Posamentier related unconformities, transgressive surfaces & maximum flooding surfaces to boundaries of system tracts in depositional sequences responding to sea level change Hydrocarbon exploration models & production reservoir models use bounding surfaces, facies assemblages & system tracts as templates for depositional models & lithofacies geometry predictions
Sequence Stratigraphy Defined
'Depositional' sequence Vail
Jervey Posmentier Van Wagoner
Sequence Stratigraphy Defined
History of Sequence Stratigraphy
Sloss recognized intercontinental unconformities them to eustasy & related Vail extrapolated eustatic signals to seismic sequence boundaries Jervey’s simulations showed seismic sequences product of cyclic sea level (base level) change Van Wagoner & Posamentier related unconformities, transgressive surfaces & maximum flooding surfaces to boundaries of system tracts in depositional sequences responding to sea level change Hydrocarbon exploration models & production reservoir models use bounding surfaces, facies assemblages & system tracts as templates for depositional models & lithofacies geometry predictions
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Sequence stratigraphy
Analytical protocol marries rules of thumb conceptual models (heuristics) to Interprets general depositional setting of layered carbonate & clastic sedimentary strata Models developed to interpret variety of datasets Work best with combination of – Outcrop – Core & well log – Seismic data May work with two or more of these data sources but are least reliable for a single data source Local differences in depositional processes, topography, and tectonics and, base level position, mean a model more appropriate to one setting, than others?
Sequence Stratigraphy Defined
Sequence stratigraphy
Analytical protocol marries rules of thumb conceptual models (heuristics) to Interprets general depositional setting of layered carbonate & clastic sedimentary strata Models developed to interpret variety of datasets Work best with combination of – Outcrop – Core & well log – Seismic data May work with two or more of these data sources but are least reliable for a single data source Local differences in depositional processes, topography, and tectonics and, base level position, mean a model more appropriate to one setting, than others?
Sequence Stratigraphy Defined
Outcrop Interpretation Pleistocene Miocene Reef Complex Majorca - Spain
Sequence Stratigraphy Defined
after Jeff Yarus
Movie time …… Miocene Outcrop
Sequence Stratigraphy Defined
Sequence stratigraphy
Analytical protocol marries rules of thumb conceptual models (heuristics) to Interprets general depositional setting of layered carbonate & clastic sedimentary strata Models developed to interpret variety of datasets Work best with combination of – Outcrop – Core & well log – Seismic data May work with two or more of these data sources but are least reliable for a single data source Local differences in depositional processes, topography, and tectonics and, base level position, mean a model more appropriate to one setting, than others?
Sequence Stratigraphy Defined
Movie time …… clastic well logs
Sequence Stratigraphy Defined
Sequence stratigraphy
Analytical protocol marries rules of thumb conceptual models (heuristics) to Interprets general depositional setting of layered carbonate & clastic sedimentary strata Models developed to interpret variety of datasets Work best with combination of – Outcrop – Core & well log – Seismic data May work with two or more of these data sources but are least reliable for a single data source Local differences in depositional processes, topography, and tectonics and, base level position, mean a model more appropriate to one setting, than others?
Sequence Stratigraphy Defined
Outcrop & Vertical Seismic Resolution 30 Hz Wavelet 15 Hz Wavelet 15,000 ft/sec.
4,580 m/sec.
Pleistocene 90 Meters ~38 Meters ~76 Meters Miocene Reef Complex Majorca - Spain 152 m wavelength
Sequence Stratigraphy Defined
305 m wavelength after Jeff Yarus
West Bahamas Seismic
Sequence Stratigraphy Defined
Movie time …… Bahamas Platform
Sequence Stratigraphy Defined
Sequence stratigraphy
Analytical protocol marries rules of thumb conceptual models (heuristics) to Interprets general depositional setting of layered carbonate & clastic sedimentary strata Models developed to interpret variety of datasets Work best with combination of – Outcrop – Core & well log – Seismic data May work with two or more of these data sources but are least reliable for a single data source Local differences in depositional processes, topography, and tectonics and, base level position, mean a model more appropriate to one setting, than others?
Sequence Stratigraphy Defined
Sequence Stratigraphy’s Fuzzy Rules Lithofacies geometries & confining surfaces transgress time Different geometries for a specific time interval Local variations in rates & direction of tectonic movement Local rates of sediment supply & accumulation Not all erosional or depositional surfaces are product of base level change Depositional models successfully predict lithofacies geometry for exploration & reservoirs Depositional model is refined as data base grows
Sequence Stratigraphy Defined
Stratal architecture & buildup style in TST vs. HST tract of Albian 19 HFS
Sequence Stratigraphy Defined
After Charlie Kerans
Example: Province of Zeeland
Tidal flat deposits Tidal channel deposits (sand) Tidal channel deposits (shells)
Sequence Stratigraphy Defined
After Jeroen Schokker, Wim Westerhoff & Henk Weerts 20008
Lithostratigraphic modelling
After Jeroen Schokker, Wim Westerhoff & Henk Weerts 20008
Sequence Stratigraphy Defined
Lithofacies modelling
Sequence Stratigraphy Defined
After Jeroen Schokker, Wim Westerhoff & Henk Weerts 20008
Time …… Varying Rates Mississippian downslope fan deposits each bed hours but section hundreds of thousands of years Intertidal Flat Flaser Structures Accumulated in Minutes
Sequence Stratigraphy Defined
Cross Bedded Ordovician Beach Carbonates Accumulation - Several Years
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Sequence stratigraphic analysis
Fundamental to sequence stratigraphic analysis: Strata deposited in order Surfaces subdivide strata into packages of beds with common depositional origin Geometric arrangement of strata & packages of strata reflect Basin filling Erosional events Commonly sequence stratigraphiy applied to sediment accumulation at basin margins in continental, marginal marine, and/or down-slope settings Fill accumulates either as: Unconfined fill over these settings Confined within erosional down-cut topography
Sequence Stratigraphy Defined
Unconfined geometric architecture Stacked layers tend to have three basic patterns : Prograding (inclined in order over and beside one another in a seaward direction) Retrograding (inclined in order over & beside one another in a landward direction) Aggrading (lie above one another vertically)
Sequence Stratigraphy Defined
Stacking Patterns - Unconfined
After Van Wagoner
Sequence Stratigraphy Defined
Stacking Patterns - Unconfined
Sequence Stratigraphy Defined
Stacking Patterns - Unconfined
Sequence Stratigraphy Defined
Confined geometric architecture
Fill post erosional down-cutting expressed by a geometric architecture of stacked layers in either succession of : Organized offset bodies and/or Randomly ordered disorganized bodies offset
Sequence Stratigraphy Defined
Confined Sedimentary Fill - Channels
Sequence Stratigraphy Defined
Stacking Pattern Rules & Problems End member stratal stacking patterns reflect interplay of accommodation accumulation (space available for sediments to fill) & rates of sediment Local vagaries in Depositional processes Topography Tectonics & so base level position mean stacking styles of geometry may merge with one another but are tied to system tracts
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Stacking, Surfaces & System tracts!
Geometric architecture of stacked layers are inferred to be related to eustatic events : Lowstand - Progradation-to-aggradational (PA) Transgression - Retrogradational geometries (R), Highstand - Aggradational-to-progradation geometries (AP) system tracts (Van Wagoner et al., 1988; Neil and Abreu, 2008) As many as five system tracts recognized but above three are most commonly used
Sequence Stratigraphy Defined
System Tracts - Reviewed
Sequence Stratigraphy Defined
System Tracts - Unconfined
3-D facies assemblages of common genetic origin with unconfined geometric architecture are interpreted to form during phases of relative sea-level cycle (Posamentier, et al, 1988) System tracts defined by: Bounding surfaces Position within a sequence Geometric stacking pattern Lowstand - Progradation-to-aggradational (PA) Transgression - Retrogradational geometries (R), Highstand - Aggradational-to-progradation geometries (AP) system tracts (Van Wagoner et al., 1988; Neil and Abreu, 2008) As many as five system tracts recognized but above three are most commonly used
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Surfaces, System tracts & Sequences Role of conceptual depositional models : System tracts are inferred to be related to accommodation generation and fill. This relationship is explained using conceptual models
Sequence Stratigraphy Defined
Bounding Surfaces
Identification & interpretation of bounding surfaces that separate layered clastic and carbonate sedimentary strata into genetically related packages, system tracts, a key to Sequence Stratigraphy Maximum Flooding Surfaces (MFS) Transgressive Surfaces regressive surfaces & transgressive ravinement surfaces) (TS) (maximum Sequence Boundaries (SB) (subaerial unconformities, regressive surfaces of marine erosion & correlative conformities).
Sequence Stratigraphy Defined
Boundaries
The movie!!
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Conceptual Models
Three conceptual models commonly used in sequence stratigraphy are separated from each other on basis of bounding & subdividing boundaries of system tracts : 'Depositional' sequence of Vail et al 1971 'Genetic Stratigraphic' Galloway, 1989 sequence model of 'Transgressive-Regressive' (T-R) sequence model of Embry and Johannessen, 1992
Sequence Stratigraphy Defined
'Depositional' Sequence (Vail et al 1971) Bounded by subaerial unconformities & marine correlative conformities Bounding surface assumed genetically connected with stratigraphic hiatus associated with subaerial unconformity that is progressively younger in seaward direction No matter systems-tract terminology used bounding surfaces of this sequence enclose: Forced regressive Normal regressive (lowstand and highstand) Transgressive sedimentary packages
Sequence Stratigraphy Defined
'Genetic Stratigraphic' Sequence Galloway, 1989 Bounded by maximum flooding surfaces.
These surfaces interpreted to form as sea level rises rapidly, sediment supply slows & organic matter accumulates sequestering radioactive materials Sequence encloses Forced regressive deposits Normal regressive (lowstand and highstand) deposits Transgressive deposits
Sequence Stratigraphy Defined
'Transgressive-Regressive' (T-R) sequence (Embry & Johannessen, 1992) Composite sequence boundary includes subaerial unconformity & marine portion of maximum regressive surface ‘Normal' & 'forced' regressive deposits are included within the 'regressive systems tract'
Sequence Stratigraphy Defined
Boundaries & Conceptual Models
After Catuneanu, 2007
Sequence Stratigraphy Defined
System Tracts - Reviewed
Sequence Stratigraphy Defined
Sequence Stratigraphy Model Tree
After Catuneanu, 2002
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
Application & nomenclature of conceptual models subject to debate Nomenclature of systems tracts & sequence stratigraphic surfaces Surfaces that should be ranked as 'sequence boundary‘ Framework of surfaces, systems tracts, selection of sequence boundaries may vary with approach, available data sets, & depositional setting Good news!!
Sequence stratigraphic method determines depositional setting of section Identification of genetic units & bounding surfaces mostly model independent. For both non-marine and marine systems, no matter characterization of 'sequence boundary', these boundaries envelope sedimentary section as through-going physical surface from basin margin to depocenter
Caveats
Sequence stratigraphic surfaces serve, at least in part , as boundaries between different genetic types of deposit Not all data lend themselves to identification of all sequence stratigraphic surfaces Not all sequence stratigraphic surfaces are present in every depositional section Depositional settings of generate an array nearshore to just offshore of depositional and erosional surfaces, many of incorporated into sequence stratigraphy In contrast, within either fluvial and/or deep-water systems, conditions favor formation of fewer key bounding sequence stratigraphic surfaces
Sequence Stratigraphy Defined
Why codify ‘rules’ for sequence stratigraphic nomenclature?
We use common terms and know their meaning Have a standard hierarchy of subdivisions Have a uniform methodology Guidance for revision Teaching resource : each new generation of students & practitioners have a common understanding
Sequence Stratigraphy Defined
Terms to Define
Surfaces Separate layered clastic and carbonate sedimentary strata into genetically related packages, system tracts System Tract Specific three-dimensional facies assemblages of common genetic origin, associated with unconfined geometric architecture & interpreted as formed during phases of a relative sea-level cycle Conceptual Models Explains configuration of surfaces and geometries that occur in layered sedimentary record in terms of: Basinal setting Rates of sediment supply & erosion (accumulation) Eustasy Tectonic movement
Sequence Stratigraphy Defined
Terms that Define - Surfaces
Separate layered clastic & carbonate sedimentary strata into genetically related packages, or system tracts Subaerial unconformity Correlative conformity (sensu Posamentier, and sensu Hunt and Tucker; the former have renamend Posamentier’s CC as the “basal surface of forced regression”). (Two different surfaces).
Regressive surface of marine erosion Maximum regressive surface Maximum flooding surface Transgressive ravinement surfaces
Sequence Stratigraphy Defined
Terms to Define – Systems Tracts
Specific three-dimensional facies assemblages of common genetic origin, associated with unconfined geometric architecture & interpreted as formed during phases of a relative sea-level cycle Falling Stage Systems Tract (FSST) Lowstand Systems Tract (LST) Transgressive Systems Tract (TST) Highstand Systems Tract (HST) Regressive System Tract Low-accommodation systems Tract High-accommodation Systems Tract Forced regression Normal regression Transgression
Sequence Stratigraphy Defined
Terms to Define – Conceptual Models Models that explain surfaces & geometries of layered sediments in terms of basinal setting, rates of supply & erosion (accumulation), eustasy, and tectonics 'Depositional' sequence of Vail et al 1971 'Genetic Stratigraphic' Galloway, 1989 sequence model of 'Transgressive-Regressive' (T-R) sequence model of Embry and Johannessen, 1992
Sequence Stratigraphy Defined
Definitions – Points to consider
Definition Alternate terms Origin of Feature Absolute time or Fuzzy time significance if any?
Sequence Stratigraphy Defined
Talk Organization
What is Sequence Stratigraphy Sedimentary Analysis & Sequence Stratigraphy History of Sequence Stratigraphy Sequence Stratigraphy Analysis Defined Geometries & Stacking Patterns System Tracts & Relative Sea Level Bounding Surfaces Conceptual Models Terminology That Should be Defined Conclusions
Sequence Stratigraphy Defined
WHAT, YOU THINK I’M AN IDIOT?
OF COURSE I WROTE DOWN WHAT WENT WHERE. OH….. WAIT…… IS THAT AN “H” OR AN “I”
"What's in a name? That which we call a rose. By any other name would smell as sweet.“ Shakespeare's
Romeo and Juliet (II, ii, 1-2)
Sequence Stratigraphy Defined
Sequence Stratigraphy – Conclusions
The fundamental key to sequence stratigraphic interpretation is the surfaces that subdivide the sedimentary section. Unfortunately the nomenclature stratigraphic surfaces is constantly understanding of sedimentary systems & their interpretation improves of each of these sequence changing as our Though changes in nomenclature are well intentioned they add to the confusion to a scientific methodology that is already overlaid with complex multi-syllable terminology A surface can be given a name that has been used before for a different surface. The innocent, not knowing the terminology has been changed, may lack understanding of the reason for the change, & feel that they are going stark raving mad
Sequence Stratigraphy Defined
Sequence Stratigraphy – Conclusions Subdivision & interpretation of sedimentary record using a framework surfaces seen in outcrops, well logs, & 2-D and 3-D seismic. Include: Surfaces of erosion & non-deposition ( Regressive Surface of Marine Erosion ) Sequence Boundaries, Forced Regression Erosion Surface, Flooding ( Trangressive Surfaces [TS or Max Regressive Surface] &/or maximum flooding surfaces [mfs] Ravinement Surfaces [RS- transgressive ) This template is used to predict the extent of sedimentary facies geometry, lithologic character, grain size, sorting & reservoir quality
Which way now?
Paul Dimitri Krynine’s alleged mantra was that: “Stratigraphy is the triumph of terminology over common sense“ Our collective hope is to circumvent this cynical position & propose a more consistent & practical set of terminology!
Sequence Stratigraphy Defined
TIME TO RELAX!
Sequence Stratigraphy Defined
Sequence Stratigraphy Defined