New geological maps of the Isle of Wight are being produced by combining old and new methods. Detailed aerial surveys will obtain geophysical data to be integrated with traditional geological mapping to create some of the most detailed geological maps ever seen of part of the UK mainland. The Isle of Wight survey uses the skills of a multidisciplinary team producing geological maps at variety of scales including:
The BGS team return to the Island in April and May 2009 to complete the ground survey and sampling. Further analysis of aerial photographs and the other remotely sensed datasets will be carried out in the summer and autumn of 2009 and a new geological map and sheet explanation will be created for publication in early 2013.
The original geological maps of 1856 (old series) and 1888 (new series) were partly updated in 1926, and its descriptive memoir reflects the keen interest in the natural world held by our Victorian forefathers. Their observational science was superb but the geological sciences have come a long way since that time and a new survey is necessary.
The most important measurements in this particular survey will be made with an electromagnetic system; this records variations of electrical conductivity in the shallow earth which may reflect land quality. The plane's other sensors measure magnetism, which can indicate rock type and structure, and natural gamma spectrometry, which reflects mainly the type and condition of the soils.
The project is based on SIGMAmobile field data capture system and uses the full range of historical datasets available in the BGS archives including aerial photography and borehole records. BGS has also worked closely with the Isle of Wight Council, Northern Petroleum, Environment Agency and Southern Water to maximise the inclusion of external data sources.
We will seek to create 3D models utilising the comprehensive seismic downhole geophysical log data and recently acquired access to a large shallow borehole geophysical dataset to aid seismic/surface correlation. Cross fertilisation from the seismic and shallow downhole geophysics with the recently acquired HiRes survey results will greatly enhance the shallow sub-surface interpretation.
Survey work includes:
A comprehensive collection of samples and thin sections of the principal sandstone and limestone lithologies have been identified, many of which were used as local building stone.
For further information about building stones contact Dr Steve Parry.