Editing Dartmoor (section)

===Geology===
[[File:Cornubian batholith.png|thumb|upright=1.8|Map showing the main granite outcrops of the [[Cornubian batholith]] in southwest England and the gravity anomaly associated with it]]

{{Main|Geology of Dartmoor National Park}}
Dartmoor includes the largest area of [[granite]] in Britain, with about {{convert|625|km2|mi2|abbr=on}} at the surface, though most of it is under superficial [[peat]] deposits. The granite (or more specifically [[adamellite]]) was intruded at depth as a [[pluton]] into the surrounding sedimentary rocks during the [[Carboniferous]] period, probably about 309 million years ago.<ref>Durrance & Laming 1982, pp.86, 101</ref> It is generally accepted that the present surface is not far below the original top of the pluton; evidence for this includes partly digested [[shale]] [[xenolith]]s, contamination of the granite and the existence of two patches of altered [[sedimentary rock]] on top of the granite.<ref>Durrance & Laming 1982, p. 88</ref>
A considerable [[gravity anomaly]] is associated with the Dartmoor pluton as with [[gravity anomalies of Britain and Ireland|other such plutons]].<ref>British Geological Survey 1997, ''Gravity Anomaly Map of Britain, Ireland and Adjacent Areas'', Smith & Edwards 1:500k</ref> Measurement of the anomaly has helped to determine the likely shape and extent of the rock mass at depth.