A Geological Map of Kent, , 1819. Scale 1: 221,760 (1 inch = 3.5 miles). Map area 48 x 54cm (18.75 x 21.25 in) within page 54 x 64.5cm (21.25 x25.25 in). Flat with old centre fold and clear plate marks. Clean, bright and in very good condition.
Non survey geological maps include maps published in journals, books and commercially. Where they are still part of a book, there will be a separate entry in the books section with more information about the book itself. Non survey maps are first listed by country - England, Wales, Scotland and Ireland - and then by author where known.
Prior to the introduction of contours late in nineteenth century, topography was depicted by hachuring which limited the construction of accurate geological sections. Prior to the Ordnance Survey maps, sections were a common way of describing geology in journal articles so that many non-survey schematic sections were produced.
The Geological Surveys published measured sections on separate sheets at six inches to a mile without vertical exaggeration. These sections crossed sheet lines and were numbered in the sequence as completed; the sections refer to one inch and six inch maps and their lines are annotated on the Old Series maps. A layout map of the sections may be accessed through the left hand 'click-to-view' directory. Most Geological Survey sections were of England and Wales of which we hold a large selection.
Within each of the 'national' divisions of the British Isles, geology has been mapped at several scales. The main scale is one inch to the mile (1:63,360) which provides almost total coverage. For England & Wales, the Old Series switched in 1900 to New Series; each have different layouts and numbering systems which may be accessed through the left hand 'click-to-view' directory. Six inch to one mile (1:10,560) maps generally were published where there was economic interest, usually coal mining. Until 1945, these were organised by county with separate layouts and numbering for each county In Great Britain. After 1945 the national grid numbering system applied Great Britain.
There is also small scale mapping at four miles to an inch, aka quarter inch (1:253, 440) and ten miles to an inch (1:633,600). The former has two different layouts and numbering systems. The latter is twentieth century and consists of two sheets that have not changed. Since 1906 the Geological Survey has published a map of the British Isles at 1:1,000,000. prior to 1906, the Directors of the Survey published national maps commercially.
The organisation in the left hand column follows the national divisions, with subdivisions of non-survey and Survey. There are two further units: 'British Isles' to cover maps that include the whole area; and 'Islands' to cover the 'off-shore' Isle of Man and the Channel Islands. There is an England and Wales section to accommodate the way the Geological Surveys have been divided historically.
The Geological Surveys historically have operated as three organisations - England and Wales, Ireland, and Scotland (in historical order). Ireland was the first island to have complete geological mapping published at the one inch to the mile scale on a layout and numbering system that has remained the same despite partition into the Republic and Northern Ireland. Scotland's mapping was the last to be completed and published at one inch scale again on a layout and numbering system that has not changed. England and Wales were mapped as a single entity at the one inch scale on the Old Series layout upto from 1845 to 1900. The format was standardised and the layout rationalised to be come the New Series which is still with us.
An index map of the layout and numbering of sheets is available for each of the one inch Geological Surveys. When you click on the particular nation in the left hand column of the British Isles page, in the next layer, you will see the option in the left hand column to click on the index map for that nation.
Mapping at six inch scale was carried out initially in Ireland at the six inch to one mile scale and was regarded as such a practical scale for the mapping exercise that it was adopted retrospectively in England and Wales and from the outset in Scotland. The Irish six inch mapping remained in manuscript form. In England and Wales, and in Scotland, areas of economic and/or professional interest were published at the six inch scale. Up to the 1940s it was organised and published on county map series. We have an extensive holding of nineteenth and early twentieth scale mapping at six inch in county series, particularly of coal mining areas. Apart from Yorkshire and Lancashire, these maps are not listed on the website yet; if you are interested in other six inch geological maps, please contact us . Upto 1900, the only method of production was engraving then hand colouring, although uncoloured maps could be purchased. Colour printing was introduced in 1900-01 in the Great Britain. However, there was a lag and hand coloured maps from the pre-1900 production persisted where colour printed maps were not yet available. Old Old Series mapping of England and Wales is hand coloured. Where hand colouring occurs on post 1900 maps, it is noted in the individual map descriptions.
Sections. Where sections are published, they are listed below the map entries. Prior to 1900 separate sheets of horizontal sections were published as hand-coloured engravings. These were selected to reveal geological structures and were not confined to individual maps. Our holdings for these are virtually all for England and Wales for which 148 sheets of horizontal sections were published. By comparison, only 9 were published for Scotland and 37 for Ireland. The Geological Survey of England and Wales published folio pages of vertical sections, mainly of coal mining areas.
The Geological Survey Maps for the British Isles are listed as follows: