The British Geological Survey (BGS) has thrown open its image library. It is now searchable and free to use for non-commercial purposes. This is a view of Salisbury Crags and Edinburgh Castle.
The picture archive contains some 50,000 images, including iconic geological features such as the Durdle Door sea arch in Dorset.
The library covers the whole UK and its diverse geology. This aerial view shows the Suilven and Canisp inselbergs, or "island mountains", in the west of Sutherland, Scotland, which were shaped by ancient glaciers.
The library is constantly updated. Pictures of the recent flooding of the River Derwent in Cumbria, are among the latest additions.
BGS staff travel abroad to study global geology and their photographs are retained in the library. Here, a night view is captured of an eruption on the island of Montserrat.
Petrologists identify rocks using a range of tools including microscopes to view samples in plain and polarised light. This is muscovite mica from Loch Nevis.
The oldest pictures in the archive date back more than 100 years. This 1910 image shows the frost-riven debris of andesitic rocks on the summit of Ben Nevis.
The library captures the working of rock by man. This image illustrates the stoop-and-room (pillar-and-stall) method of extraction in a Gorebridge, Midlothian, quarry.
And here, two workers at Pitlochry Depot, Perthshire, are processing Scottish mica. The mineral has been used in everything from lubricants to electronics.
All manner of fossil forms are pictured. The popular trilobite, a marine creature, disappeared in the mass extinction at the end of the Permian Period about 250 million years ago.
The BGS believes the library will be a big help to the education sector. The images can be downloaded by schools and universities to use in presentations and projects.
What are these?