Sequence Stratigraphy, Emery & Myers - Free ebook download as PDF File .pdf) or read book online for free. 4 - Sequence Stratigraphy, Emery _ Myers aracer.mobi - Free download as PDF File .pdf), Text File .txt) or read online for free. Sequence Stratigraphy. Editor(s). Dominic Emery; Keith Myers. First published: 27 August Print ISBN |Online ISBN
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Sequence Stratigraphy, Emery & Myers Report. Post on Oct Views. Category: Documents. Downloads. prev. next. out of 4 - Sequence Stratigraphy, Emery _ Myers aracer.mobi Siliclastic Sequence Stratigraphy: Application to Sequence Stratigraphy: Application. Blackwell Science, v p. The innovation and refinement of the techniques and concepts of sequence stratigraphy has been one of the most exciting.
Elsevier, Amsterdam, p. Posamentier, H. Siliciclastic sequence stratigraphy: Catuneanu, O. Precambrian sequence stra- concepts and applications. Sedimentary Geology 1—2 , 67— Eustatic controls on clastic deposition II — Eriksson, P. In: Wilgus, C. SEPM Spec. Eustatic controls on clastic depo- Tucker, M. Towards the standardization of sequence stra- sition I — conceptual framework.
Earth-Science Reviews 92, 1— Flooding surfaces, depositional elements, and accumulation Integrated Approach, vol. Rift-related linked depositional systems and their seismic Basin, northeast Brazil. Unpublished Ph. Geological Society Special Publication 71, 35— Emery, D. Sequence Stratigraphy.
Blackwell, Oxford, p.
Vail, P. Seismic stratigraphy and global changes of sea- overview. Special Publication of the International Association of Sedimentolo- level. In: Payton, C. AAPG Memoir 26, pp. Frostick, L. Sedimentation in divergent plate-margin basins. Special Van Wagoner, J. Silici- Publication of the International Association of Sedimentologists 20, — Quantitative geological modeling of siliciclastic rock sequences High-Resolution Correlation of Time and Facies.
In: American Association of and their seismic expression. Chronostratigraphic charts are a means of showing the time relationships of these systems, and their relationships to surfaces of non-deposition, condensation and erosion. These surfaces have little or no thickness in the rock record, and their true significance can be appreciated better by considering them in the time dimension.
The construction of chronostratigraphic charts provides a check for the interpreter, ensuring that the interpretation makes sense in time as well as in space. It also ensures construction of a time-framework for measuring variables such as sediment flux, subsidence, etc. In addition, chronostratigraphic plots of the proximal limit of topset deposf.
The basic procedures for producing chronostratigraphic charts and coastal onlap plots from seismic data were described initially by Wheeler ; chronostratigraphic charts arc also known as Wheeler diagrams , Mitchum et al. A terminology for the description of rock units in time was proposed by Schultz , who introduced the term chronosome for a rock unit bounded by time planes.
A chronostratigraphic chart has time as the vertical axis, with a spatial horizontal axis. On the chart are plotted the distribution of systems tracts, bounded by surfaces of onlap, toplap, downlap, etc. Within the systems tracts, the limits in time and space of the facies units may be shown. Chronostratigraphic charts are most easily and accurately constructed from seismic data, where the relative positions of the depositional units in time and space can be determined more clearly.
The principles of chronostratigraphic construction, like many of the principles of seismic stratigraphy, are based on the assumption that seismic reflectors follow bedding, that bedding planes are isochronous, and hence seismic reflections approximate to time-lines section 3. The corollary of these assumptions is that reflection-bounded packages are chronosomes. This process will be illustrated by reference to Fig.
Note that anyone seismic line does not necessarily sample all of the stratigraphy, and the chronostratigraphic section constructed from it will not be a complete representation of deposition within the basin. It uses the chronostratigraphic range of fossil species to correlate stratigraphic sections, and their palaeoenvironmental preference to provide information on depositional setting.
Prior to the advent of seismic data, biostratigraphy was the only means by which geologists could correlate timeequivalent depositional sections accurately. However, many of the fossil groups favoured by early palaeontologists, certainly prior to the middle of this century, tended to be forms that inhabited the sea-bed benthos rather than the water column plankton. As a consequence, these benthic correlations often had a greater affinity to palaeoenvironmental conditions and depositional facies rather than chronostratigraphy Loutit et al.
Indeed the dose relationship between the presence of these benthic markers and lithofacies was probably responsible for prolonging the common practice of treating lithostratigraphic correlations as chronostratigraphic events.
Seismic stratigraphy has now largely superceded biostratigraphy as the primary correlative tool in subsurface basin analysis. However, biostratigraphy, together with other dating methods, such as isotope stratigraphy Emery and Robinson, and magnetostratigraphy, play an important role in providing the chronostratigraphic control to seismic correlations Armentrout, , Loutit et al.
Also, without the aid of biostratigraphy, seismic stratigraphy is limited in areas with complex structure. This chapter will show how biostratigraphic data can be integrated with other techniques to enhance and constrain sequence stratigraphic interpretations, beginning with an 6.
This is best obtained through the integration of marker taxa from several different fossil groups. The most useful fossils are those which, as they evolved, exhibited distinct and rapid morphological change, so as to be unequivocally identifiable.
It is also important that they are distributed widely, and therefore correlateable within and between basins, and occur in sufficient abundance that their presence is a statistically viable event. Several macrofossil groups, such as the ammonites and goniatites, together with the larger foraminifera, are of particular value, but the limitation of sample size in the petroleum industry has meant that small fossils, usually less than a few millimetres in diameter and as small as 4!
The three most useful groups include: microfossils e. The advantage of using small fossils is that, in favourable palaeoenvironments, they usually occur in abundance. Figure 6. Recent attempts to apply sequence stratigraphic concepts to fluvial systems has met with less success because the role of relative sea-level fluctuations in fashioning the fluvial stratigraphic record is less clear Posamentier and Vail, ; Posamentier, ; Shanley, ; Shanley and McCabe, , , , ; Westcott, Fluvial systems respond to a bewildering set of external allocyclic and internal autocyclic controls Schumm, , ; Schumm and Ethridge, The problem is compounded by rapid lateral facies changes and a lack of internal features in thick alluvial successions which allow them to be sub-divided into time stratigraphic units.
As a result, the application of sequence stratigraphy to fluvial systems is still in its infancy, with concepts and models still the subject of lively debate Galloway, ; Miall, , ; Boyd et at.
The early sections of this chapter focus on depositional processes and fluvial channel patterns. The concept of the graded river profile is then introduced as the primary control on the development of accommodation in fluvial systems. Finally, the potential role of relative sea-level change in influencing the fluvial record is reviewed and illustrated with a number of examples.
Fluvial systems are one of the best studied of all depositional environments. A detailed review of fluvial depositional environments is beyond the scope of this chapter and the reader is referred to a number of excellent summaries on this subject Cant, b; Miall, , ; Ethridge and Flores, ; Collinson and Lewin, ; Collinson, ; Ethridge et al. Four traditional styles of fluvial channel are commonly recognized; braided, meandering, anastomosing and straight Leopold and Wolman, ; Leopold et al.
These categories are useful but must be considered only as tendencies within a spectrum of channel types or classes see discussion in Miall, River channel patterns are controlled by discharge, sediment supply and gradient Bridge, As a result, changes between channel classes are gradational, with one or a number of different channel patterns containing similar morphological elements.
Straight rivers have well-defined single channel courses with stable banks flanked by levees. Anastomosing rivers form interconnected networks of low gradient, relatively deep and narrow channels of variable sinuosity, characterized by stable, vegetated banks composed of fine-grained silt or clay Smith and Smith, ; Putman, ; Rust and Legun, ; Nanson et at.
Lateral channel migration is limited by the development of fine grained bank material Paralic Successions 8. As such they are extremely sensitive to changes in relative sea-level and are therefore particularly suitable for highresolution sequence stratigraphic analysis.
The chapter commences with a summary of difff'rent paralic depositional systems, and a discussion of highresolution sequence stratigraphy. It proceeds by showing i how stratigraphic signatures vary in distinct paralic environments; and ii how sequence stratigraphy can be applied to paralic petroleum reservoirs.
The chapter concludes with an analysis of the seismic expression of paralic successions, and how paralic successions may vary during a sea-level cycle. Deltas comprise a Western Canadian Basin Table 8. This combined approach based on sequence stratigraphy and sedimentary processes has advanced from early studies of the late , which emphasized simple model-driven interpretations of deep-marine clastic systems based upon seismic data e.
Mitchum et a! This chapter first reviews the range of sediment transport mechanisms in deep marine settings and the controls on coarse clastic deposition within a basinal setting. The principle large-scale deep-marine clastic depositional syste'ms and the controls on their development are discussed.
Th is information is used to develop a suite of sequence stratigraphic models, which show the variety of depositional systems that may develop within a given systems tract.
Sediment gravity flows form a broad 9. Four basic types of sediment gravity flow are recognized, and include the following Table 9.
The remaining types of sediment gravity flow are regarded as transient phenomena; occurring between the initiation of sediment movement by slides and slumps, and the final stages of sediment and fluid transport by fully turbulent turbidity currents Lowe, , ; Postma, Middleton x The term turhidite facies is used here in the context of Mutti and Ricci-Lueehi to refer ro all sediments deposited hy sediment gravity flows and not just to turhidity eu rrents.
Noel James' apt quotation neatly sums up why carbonates, as living systems, require a rather different sequence stratigraphic approach to their inert siliciclastic counterparts. Fortunately, this has not resulted in a proliferation of new terms and concepts, as many of the existing sequence stratigraphic principles discussed in the first four chapters are valid. However, the range of environmental factors and of carbonate platform geometries add two new dimensions that extend the range of interpretation of any carbonate succession.
Sequence successions, and to show the utility of sequence stratigraphy provides an even more refined way stratigraphy in predicting aquifer geometries and to address stratal architecture, hydrologic distributions. This information is critical in systems, and basin-scale processes. The summ- formulating paleohydrologic models for ary of sequence stratigraphy presented here is sedimentary basins. It is instead intended to have been made in the understanding of basin provide the basic principles of sequence formation and evolution e.
Turcotte and stratigraphy as it applies to basin analysis and Ahern, ; Paola, ; Allen and Allen, paleohydrologic studies. For more compre- ; Miall, The relationships between hensive reviews see Van Wagoner et al.
Paola, , and Miall It is important aquifer lithologies. Paleohydrologic subsidence and changes in the rate of this systems in basin-filling sedimentary successions subsidence that cause the onset of deposition and depend on the shape, size, and internal the systematic changes in stratal architecture that properties of porous and permeable lithologies. Allen and their relatively simple relationship to basin and Allen, , Miall, Subsidence, in evolution.
Such plumbing systems Cloetingh, ; Roberts et al.
Idealized geometries of sand bodies that form the "plumbing systems" of clastic rock-dominated basin-filling successions modified from Galloway and Hobday, Weber, ; Allen and Allen, ; Galloway and Hobday, Diagram showing some of the possible scales of hydrologic heterogeneity in a fluvial basin-filling succession after Weber, For example, fluvial channel sand bodies solution can modify this relationship.
For that form the aquifer systems in many sedimen- spherical grains, porosity and permeability tary basins are actually isolated to amalgamated increase with increased sorting and grain size ribbon-like to sheet-like bodies encased in rela- Krumbein and Monk, As the shape of tively impermeable mudstone layers Galloway the grains becomes more irregular, however, it and Hobday, Such sand bodies in turn becomes difficult to predict hydrologic have internal heterogeneities due to interbedded properties of the sediment Allen and Allen, mudstones, cross bedding, and variations in Elongate and tabular grains, such as fabric, such as grain size and sorting Fig.
Monk, Porosity and permeability is more At the thin section scale micrometer to dramatically lowered as the amount of mud millimeter scale , grain size and sorting are seen matrix increases sorting decreases; e. Barrier Island Succession B. Fining upward and coarsening upward facies successions and their generalized porosity and permeability relationships modified from Selley, At the centimeter-scale, bedding ; Selley, In contrast, fining-upward including laminae, cross-bed foresets, and facies successions characteristic of fluvial graded beds introduces major aquifer environments, such as point bar deposits, show a heterogeneities Fig.
At the decrease in porosity and permeability moving up meter-scale, bedding and lithologic variation the succession Fig 2. At the kilometer-scale anisotropy.
For example, meandering fluvial sub-basin scale , stratigraphic architecture stream systems with pod-like to ribbon-like sand becomes the dominant control over aquifer bodies encased in mudstones show extreme systems. This control is due to major changes in aquifer heterogeneities Fig.
Because porosity processes, such as uplift, subsidence, eustatic and permeability increase with increasing grain sea-level change, and climate Allen and Allen, size and sorting, general facies successions1 or For example, coarsening-up- interlinking e.
Walker and Cant, ; Kraus, ward facies successions typical of prograding ; Shanley and McCabe, ; Wright and shoreface and deltaic environments show Marriott, ; Shanley and McCabe, ; increasing porosity and permeability within each Galloway and Hobday, ; Miall, In marine settings these include upper modified through diagenetic processes.
These are systems in which progradation of sand Channel-filling sands and gravels form the over mud-rich units typically occurs e. The porosity, hydraulic conductivity, Galloway and Hobday, ; Miall, There are two types of fluvial at their bases Fig. Aquifer heterogeneity and compartmen- properties: braided and meandering. Braided talization depend on the depositional environ- streams are marked depositionally by variable ment, with wave-dominated deltaic systems discharge rates, flow that is not confined to a typically having the most complex potential single channel, high sediment load transported vertical and lateral heterogeneities and degree of as bedload, and minor mud deposition e.
It is impor- Schumm, ; Best and Bristow, ; Miall, Braided streams produce sand and gravel Table 2. Comparison of general vertical and lateral aquifer heterogeneity in common sedimentary environments.
Note that these relationships can be very different after burial diagenesis Modified from Tyler and Finley Vertical Lateral heterogeneity heterogeneity Low High Positive effect Moderate Negative effect on aquifer properties on aquifer properties Low Wave-dominated delta front Channel-mouth bar Fluvial-dominated Positive Barrier core and shoreface Muddy strandplain delta front effect Sandy strandplain Mixed-load meanderbelt Back barrier lagoon on aquifer Suspended-load properties meanderbelt Cross-bedded sand sheet Alluvial fans, Shelf bars Braided channel bed- Moderate Aeolian dunes Fan delta load Wave-modified delta front Distal shoreface, tidal Tide-dominated delta estuary fill front High Turbidite lobes Coarse-grained Turbidite channel fill Negative Turbidite sheets meanderbelts Estuary effect Shelf sand sheets Sandy tidal flats on aquifer Braid delta lobes properties 23 A.
Meandering Stream System Avulsion Aluvial fans Lens-like, semi-isolated sand bodies in cross-section; ribbon-like in map view Figure 2.
Block model showing attributes of a braided fluvial depositional system. The cross sectional view shows the amalgamation of channel sands and gravels in the near absence of mud that produces sheet- like geometries. Block model showing attributes of a meandering stream system. The cross section shows channel sands surrounded by mud producing isolated pod- and ribbon-like geometries modified from Walker and Cant, Such coarse-grained, laterally continuous Walker and Cant, ; Galloway and Hobday, systems of amalgamated channel deposits result 24 in high porosity, high degree of hydraulic basin-filling stratigraphic successions has been conductivity, and a relatively low degree of to apply a simple lithostratigraphic model in aquifer compartmentalization.
Thin interbedded which similar lithologies are correlated across mudstone beds, paleosoil horizons, and clay basins.
Implicit in this approach is the infiltration from surrounding units can, however, assumption that similar lithologies formed at the increase the degree of compartmentalization same stage of basin evolution. This may lead to Weber, ; Galloway and Hobday, In fact, some basin-filling successions to one sinuous channel, have a lower gradient exhibit simple fining-upward trends when and velocity than braided systems, and deposit viewed at a large scale hundreds of meters to large quantities of mud e.
Walker and Cant, kilometers , but are complex internally when ; Bridge, ; Miall, Because viewed on a smaller scale meters to tens of meandering streams often produce ribbon- to meters.
This reflects the evolution of the basin pod-like bodies that are encased in mud-rich from the onset of subsidence sometimes layers, they exhibit a high degree of aquifer tectonically driven to a state of gradual and compartmentalization and a variable hydraulic simple subsidence. However, basin evolution conductivity Fig. Posamentier and The degree of channel amalgamation is Allen, b; Miall, Bridge, ; Kraus and Sequences and their components Aslan, , and 3 the amount of space The basic stratigraphic unit of available for sediment deposition Shanley and sedimentary basin-fill is the depositional McCabe, Vail et al.
Posamentier et al. Sequence to trace across a sedimentary basin because they stratigraphy provides a means to understand can grade laterally into a conformable surface stratigraphic successions and paleohydrologic toward the basin depocenter Posamentier et al.