This is the core collection of photographs in BGS it represents photographs taken by professional photographers and selected by subject and quality for public reference in the BGS libraries. The collection dates from c 1890 to c.1995 and is organized in a series of sub-collections depending on which office the photographers were based. The collection covers photography taken in the field during the geological mapping programme. Series A, the main Land Survey collection for England and Wales, are all taken by professional photographers and are of high quality. Dates from c.1890 to the start of the current "P" system, the first 7500 are glass plates. Series B, Edinburgh, part of the main Land Survey collection for Scotland, full plate size and all glass plates. Series C, Edinburgh, part of the main Land Survey collection for Scotland, half plate size. Series D, Edinburgh, part of the main Land Survey collection for Scotland consists of large format negative size with additional 35mm transparencies, earlier parts of the collection are black and white, later, colour. Series L, Keyworth, the main Land Survey collection for Northern England and Wales emanating from the Leeds Office, all are taken by professional photographers and include large format black and white, colour originals and colour 35 mm transparencies. Access constraints are only physical constraints relating to handling negatives and glass plates. scans are available in the Geoscience Imagebase. Photographs are either: Out of copyright; Crown or NERC.