Appalachian basin stratigraphic response to convergent‐margin structural evolution

Abstract

From study of Palaeozoic formations in the Appalachian foreland basin, a predictive stratigraphic model is proposed based on facies tract development during convergent‐margin structural evolution. Five major facies tracts are recognized: shallow‐water carbonates that formed during interorogenic quiescence and initial foreland subsidence; deep‐water siliciclastics that accumulated in the proximal foreland basin during early collision; syn‐collisional shallow‐water siliciclastics; syn‐collisional, channellized fluvial sandstones that aggraded in the proximal foreland; and progradational shoreline sandstones that were deposited in response to filling of the proximal foreland. Two other facies tracts that occur are organic‐rich siliciclastics (‘black shales’), which accumulated in oxygen‐deficient areas of low clastic‐sediment influx, and incised valley‐fill deposits, which formed where subsidence rate was low. Because the origin of each facies tract is dependent upon a unique combination of rate of accommodation change and rate of sediment supply, facies tract distribution is predictable from spatial and temporal patterns of subsidence and uplift associated with plate convergence. Alternating phases of thrust loading and quiescence caused fluctuations between underfilled and overfilled conditions during Palaeozoic evolution of the Appalachian basin. Along‐strike variations in stratigraphic thickness, facies tract distribution, and development of unconformities in the Appalachian basin reflect the influence of structural irregularities along the collisional margin. In distal parts of the Appalachian foreland and in areas of structural recesses, eustatic influence on stratigraphic patterns is expressed more clearly than in areas of higher subsidence rate.

Detrital zircon U–Pb ages of the Proterozoic metaclastic-sedimentary rocks in Hainan Province of South China: New constraints on the depositional time, source area, and tectonic setting of the Shilu Fe–Co–Cu ore district

“…4d in Xu et al, 2013), consistent with the occurrence of most foreland basins (Castle, 2001); (2) the sedimentary facies of both successions changes from neritic fine-grained siliciclastics intercalated with thin carbonate (the First to Fifth members of the Shilu Group), through neritic-thalassic impure carbonate intercalated with siliciclastics (the Sixth member of the Shilu Group), to shoreline-channelized fluvial sandstone (the Shihuiding Formation; Fig. 2), typical of foreland basin deposition (Castle, 2001); (3) there was no contemporaneous magmatic activity; and (4) both successions are defined by two major ductile shear zones, i.e. E-trending Changjiang-Qionghai and NE-trending Gezhen (Fig.…”

Chemical, Physical, and Risk Characterization of Natural Gas Storage Produced Waters

“…This high salinity is consistent with published values of formation water resistivities for the Oriskany Sandstone (Roen and Walker 1996). High salinity waters of the Oriskany Sandstone and other deeply buried sedimentary formations of the Appalachian basin are interpreted as basinal brines, consistent with accumulation of thousands of feet of sedimentary strata in a tectonically active basin (Castle 2001). As the waters remain buried deeply for an expanse of geologic time, ionic concentrations would be expected to increase beyond the normal salinity of seawater trapped in the formation at the time of sediment deposition.…”

Geochemistry and depositional history of the Union Springs Member, Marcellus Formation in central Pennsylvania

“…The Marcellus Formation was deposited during the Middle Devonian in the northeast-southwest-trending Acadian foreland basin, which is estimated to have water depths of at least 140 m (450 ft) in the deeper parts of the basin at the onset of deposition (Ettensohn, 1985a;Castle, 2001;Kohl et al, 2014). Formation of the basin resulted from thrust-loading subsidence due to the oblique collision of the Avalonia microcontinent with Laurentia during the Acadian Orogeny in the Late Silurian though the Late Devonian (Lash and Engelder, 2011).…”