Abstract Outcrop sections containing excellent physical and biogenic sedimentary structures within the Late Permian Ecca Group are exposed within the Tanqua Karoo that show the transition from shelf margin delta through to slope and basin floor fans. The Tanqua submarine fan complex comprises six regionally distinct fan systems, five of which form a progradational stack with the sixth fan, to the south, downlapping onto the fifth fan. Progradation of the deltaic deposits across the basin has been in response to a decrease in accommodation space created by relatively high rates of sedimentation within the foreland basin setting. The sedimentology and sequence stratigraphy of the Hangklip Fan represents a shelf margin delta feeding downdip slope fan deposits. Wave ripples, swaley cross-stratification and trace fossils, including Gyrochorte , suggest substantially shallower depositional conditions than slope fan deposits, which are devoid of such features. Erosional slump scars, cutting into laminated shale with chaotic infill of sand intraclasts, point toward slope depositional processes that are not in evidence in the underlying submarine fan deposits.

Abstract The area of northern Mexico and Texas combines elements from two different tectono-stratigraphic provinces—(a) the Gulf of Mexico province (GOM province), located along the northwest rim of the present-day Gulf of Mexico in northeast Mexico and south Texas, and (b) the western Pacific Mexico province (WPM province), located in northwest Mexico and west Texas—and thereby enables one to compare and contrast Gulf of Mexico-driven versus Pacific-driven tectonostratigraphic processes. The area addressed in this paper (that is, the northwest rim of the Gulf of Mexico) contains elements related to both Gulf of Mexico passive-margin development (principally the stratigraphy) and to the Pacific-related convergent margin (arc) tectonism (chiefly the structure). The emphasis in the paper is on the GOM province, with particular reference made to the Sierra Madre Oriental region in the vicinity of the cities of Monterrey and Saltillo, in northeast Mexico.

Abstract The Late Permian Ecca Group (1300 m thick) in the Tanqua Karoo consists of a basin floor fan complex (400 m thick), overlain by river-dominated deltaic deposits and associated updip fluvial deposits. This succession is subdivided into two “third-order” depositional sequences with several superimposed high-frequency, “fourth-order” depositional sequences. The Tanqua submarine fan complex contains six regionally distinct fan systems (24 to 60 m thick), five of which form a progradational stack, as revealed by their spatial distribution and regional facies variation. The sixth fan is situated to the south and downlaps onto the fifth fan. This long-term (third-order) progradational pattern records a combination of reduced accommodation space and/or increased sediment supply. Each fan system is assigned to the lowstand systems tract of each high-frequency, fourth-order sequence, and the particular attributes of each fan system are a consequence of their respective positions within the lower-frequency third-order sequence.

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Abstract The Middle Triassic Latemar platform (740 m thick, 5–6 km wide) provides a seismic-scale outcrop example of an intact carbonate shelf-to-basin transition, ideal for integrating sequence stratigraphy with facies and cyclic stratigraphy. This subcircular, high-relief buildup records two third-order (1–10 m.y.) accommodation sequences within the platform interior, the Lower Ladinian sequence (8 m.y.; 400 m thick) and the Upper Ladinian sequence (6 m.y.; 340 m thick). The Lower Ladinian sequence developed atop a widespread, low-relief Middle Anisian carbonate bank (60 m thick). Underlying subtidal cycles of the Middle Anisian bank thin upward into the basal, subaerial sequence boundary of the Lower Ladinian sequence reflecting decreasing third-order accommodation. Above this sequence boundary, platform-interior facies of the Lower Ladinian sequence retrograde. This retrogradation results in superimposition of Ladinian basinal and foreslope facies atop the underlying, horizontal, shallow-water bank along its periphery. The transgressive and highstand systems tract of the Lower Ladinian sequence and transgressive systems tract of the Upper Ladinian sequence are marked by long-term, systematic vertical facies changes (subtidal vs. subaerial exposure-dominated facies) and variation in stacking patterns of aggradational high-frequency, 20 k.y. cycles within the platform interior. The maximum flooding surface in the Lower Ladinian sequence is a prominent surface in a platform interior position that loses its identity laterally into reef margin, foreslope, and basinal facies. A stratigraphically transitional sequence boundary caps the Lower Ladinian sequence, marked by an interval of vertically superimposed thin subaerial tepees. Beneath this interval, high-frequency cycles are thinning-upward, and above they are thickening-upward. At this sequence boundary there is no downward shift in overlying facies, no lowstand wedge in the downdip position, particularly in the case of isolated buildups such as the Latemar, and no erosional hiatus. Only the transgressive systems tract of sequence L2 is preserved at the Latemar owing to Late Ladinian-Early Carnian volcanism and tectonism, which terminated carbonate platform deposition.