sea water is the agent responsible for the deposition of sediments.
name the agents responsible for the deposition of sediments?
sea water
na
na
starting at the basement of the structure, the area of interest overlies variscan externides consisting of devonian and carboniferous sediments in imbricated thrust sheets. the hercynian basement was rather thin in origin with the thrust emplacement in a north-northwest trend developed most likely with a strike-slip fault. after the conclusion of the initial hercynian deformation, normal reactivation of these same faults occurred along with differential subsidence beginning in the late carboniferous as a direct result from the northwest/southeast trending wrench movements. the sands created within this period lie in an unconformed manner atop the devonian and carboniferous basement. the asymmetrical grabens are found within these sands and through the use of dating techniques mark the point in history of basin initiation during the late carboniferous. following this stage the basin underwent a period of erosion removing approximately 10 km of sediment from the area with the following permian sediment deposition being dictated by the former hercynian structure. this semi-arid, desert sedimentation occurred on the western portion of the basin with the clasts eventually thinning as they progress towards the east side of the basin. triassic sediments sit atop of the permian layer again in an unconformed manner with the makeup being mainly sand and silts. like the former stage, the triassic sediments were first concentrated on the west side of the basin but also overwhelmingly appeared in the southwest as a direct result from marine transgression. the jurassic period followed with the same marine sedimentation, but by the end of the period, sea-level began to shallow leaving behind shallow marine sediments. the cretaceous period marks a major transition as the area became unstable with the basement faults reactivating and additional deposition of 1000m of brackish non-marine/freshwater sediments along with major uplift of the basin margins. the later cretaceous consisted of deposition almost entirely of chalk with a basin wide unconformity delineating the period between the tertiary and late cretaceous. these sediments are important as they represent the marker bed that the inversion of the basin begins.
wessex basin