Standard British Geological Survey Maps (BGS). The 1:50,000 series is the standard and most commonly used type of geology map for UK Geology. Geology covers either the Solid Bedrock, or the Superficial Deposits. These maps are available in Flat, or Folded editions, and they cover a vast majority of the UK. This series also has an extensive number of memoirs and map explanation books. Our easy to use map search tool will help you find the specific map for your requirements.