The Seabed Geology 10k: Bristol Channel is a digital geological map portraying the distribution of the different geological substrate units (either of bedrock or unlithified deposits) present on the seabed at a 1:10 000 scale. Additionally, to the Seabed Substrate layer, this dataset also includes i) a Geomorphology layer, revealing the presence and distribution of seabed morphological and geomorphological features and ii) a Structural Geology layer, that delineates the principal structural features observed at rockhead. The bedrock geology is divided into seven stratigraphical units: Pembroke Limestone Group (PEMB); Mercia Mudstone Group (MMG); Penarth Group (PNG); the Lias Groups' St Mary’s Well Bay (STM), Lavernock Shales (LVN) and the Porthkerry (PO) members; and the Inferior Oolite Group (INO). The Lexicon code of the stratigraphical units is provided in parentheses, as defined in the ‘BGS Lexicon of Named Rock Units’. The superficial deposits mapped are comprised of only marine sediments that were classified based on their grain size. However, Folk classification was not used to define the sediment classes. The sediments are divided into Gravel (V); Sand and Gravel (XSG); Sand (S); Sand and Mud (XSM); Mud (M); and Gravel, Sand and Mud (XVSM). The RCS code of the stratigraphical units is provided in parentheses, as defined in the ‘BGS Rock Classification Scheme’.
