The Weardale Granite pluton is the largest and the only one that has been proved (sampled), after the Rookhope Borehole confirmed Martin Bott's hypothesis that a large negative gravity anomaly under Weardale represented a low-density igneous intrusion.
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In the early 1960s, a borehole was drilled at Rookhope by Durham University, and proved the existence of the intrusion at a depth of 390 m.
Rookhope |
During his tenure he supervised the drilling of the Rookhope borehole discovering, as predicted by his colleague Martin Bott, the presence of a concealed granite underlying the Pennines.