The Lower Carboniferous Stainmore Basin, N. England: extensional basin tectonics and sedimentation

Abstract

Recently released industry seismic data image a 6 km thick Dinantian succession in the Stainmore Basin, and are used to interpret deposition in response to extensional subsidence. The basin is bounded to the north by the Lunedale–Wigglesworth–Butterknowle en echelon suite of normal faults. An early (?Courceyan–?Arundian) syn-rift sequence more than 4 km thick includes footwall-derived clastic fans. A basinal terrigenous sequence deposited through the Arundian, Holkerian and early Asbian contrasts with coeval carbonates on the Ravenstonedale Shelf and the Askrigg Block. Deposition continued in the basin whilst the Alston block and northern parts of the basin were emergent during early Asbian times. A late Asbian relative base level rise and the possible cessation of active rifting allowed both basin and structural highs to be inundated by shallow marine carbonates. Rhythmic ‘Yoredale’ sedimentation followed. Dinantian depositional patterns reflect the interplay between active extensional faulting, a suspected local inversion event, changes in sediment influx rates, sea level variations and differential rates of compaction between basement highs and the basin. However, error margins on the available biostratigraphy and timing of active faulting prevent the detailed separation of these variables and their impact on sedimentation in the Dinantian.