Lower Devonian–Lower Mississippian(?) metasedimentary rocks in the southernmost Appalachian orogen near the southeast corner of Laurentia record a period of continental-margin stabilization bracketed by orogenic events best assigned to the early Acadian and earliest Alleghanian orogenies. These strata are in the Talladega belt, a far-traveled allochthon forming the southwestward extent of the western Blue Ridge. In the allochthon, lower Paleozoic trailing-margin carbonate-shelf rocks are unconformably overlain by a >2.5-km-thick early Acadian (Silurian(?)–Lower Devonian) clastic wedge, derived from basement-cored uplifts to the south and southeast. Deposition of this clastic wedge was followed by continental-margin stabilization and deposition of a starved-basin sequence containing widespread Lower Devonian–Lower Mississippian(?) chert near the outer shelf margin. The chert sequence grades northeastward through a shelf–slope–basin-plain transition into a thick black-shale basinal facies. These units were deposited during the classic Acadian orogeny in New England and the Catskill delta's progradation across the central Appalachian foreland—the major clastic response to Acadian uplift. The Talladega sequence subsequently was subjected to low-grade regional metamorphism and pervasive deformation, possibly as late as middle Mississippian, during what were probably the initial stages of the Alleghanian orogeny. Deposition of the Lower Devonian–Lower Mississippian(?) sequence of the Talladega belt thus represents a significant hiatus in deformation along southeast Laurentia, bracketed first by orogenic activity related to early Acadian (Silurian(?)–Early Devonian) foundering of the early Paleozoic shelf and deposition of a clastic wedge and later by earliest Alleghanian regional dynamothermal events.

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