Part of the Earth Sciences CommonsThis Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska -Lincoln. AbstractSequence stratigraphy emphasizes facies relationships and stratal architecture within a chronological framework. Despite its wide use, sequence stratigraphy has yet to be included in any stratigraphic code or guide. This lack of standardization reflects the existence of competing approaches (or models) and confusing or even conflicting terminology. Standardization of sequence stratigraphy requires the definition of the fundamental model-independent concepts, units, bounding surfaces and workflow that outline the foundation of the method. A standardized scheme needs to be sufficiently broad to encompass all possible choices of approach, rather than being limited to a single approach or model.A sequence stratigraphic framework includes genetic units that result from the interplay of accommodation and sedimentation (i.e., forced regressive, lowstand and highstand normal regressive, and transgressive), which are bounded by "sequence stratigraphic" surfaces. Each genetic unit is defined by specific stratal stacking patterns and bounding surfaces, and consists of a tract of correlatable depositional systems (i.e., a "systems tract"). The mappability of systems tracts and sequence stratigraphic surfaces depends on depositional setting and the types of data available for analysis. It is this high degree of variability in the precise expression of sequence stratigraphic units and bounding surfaces that requires the adoption of a methodology that is sufficiently flexible that it can accommodate the range of likely expressions. The integration of outcrop, core, well-log and seismic data affords the optimal approach to the application of sequence stratigraphy. Missing insights from one set of data or another may limit the "resolution" of the sequence stratigraphic interpretation. 1 2 c a t u n e a n u e t a l . i n e a r t h -science r e v i e w s 92 (2009)

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Distinctive peritidal tepee antiform structures, buckled margins of saucer‐like megapolygons are common in marine vadose fenestral and pisolitic limestones and/or dolomites of carbonate platform sequences and occur in intertidal and supratidal carbonates ranging in age from Silurian to Holocene. These megapolygons commonly form and are sometimes truncated before the deposition of the next sedimentary layer. The megapolygons result from the expansion of surface sediments by as much as 15%. The expansion is caused by the following continuously repeated sequence of processes: (1) Desiccation and thermal contraction causing small fractures; (2) phases of wetting causing enlargement of fractures; (3) phases of crystallization of calcium carbonate and other minerals causing the enlargement, fill and cementation of the fractures. Precipitation is from brines and meteoric waters; (4) hydration of minerals, thermal expansion, breaking waves and faulting may add to this disruption. The development of the tepee fabric can be traced from an initially cemented subaerial fenestral crust, exhibiting expansion and compressional structures, to a completely disrupted and brecciated sediment riddled by a labyrinth of fractures and solution cavities. These spaces are filled by numerous phases of internal marine and fresh‐water cement and sediment, the latter containing penecontemporaneous or younger marine faunas. Peritidal tepees are useful tools for geologic reconstruction and provide evidence of subaerial exposure; a tropical to subtropical climate; and back‐beach or back‐barrier deposition. Proper identification of tepees is of economic importance, because they provide good early porosity and permeability for petroleum entrapment and a site for mineralization. Aesthetically, tepee rocks are a fine kaleidoscopic decorative stone.

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