Metallogenetic Significance of a North Pennine Springwater

D. A. C. Manning and D. W. Strutt
Department of Geology, the University, Manchester M13 9PL
Weardale Minerals Ltd., Blackdene Mine, Bishop Auckland DL14 1EG

Abstract: The occurrence is reported of a saline spring water from Weardale, which compositionally closely resembles other saline waters derived from the Carnmenellis granite, southwest England. The total dissolved solutes achieve approximately 38 000 mg/L, and alkali geothermometers suggest equilibration temperatures of approximately 150°C, equivalent to a depth of 4 km. Using Na, K and Li it is possible to compare the composition of the spring water with those of other spring waters derived from Carboniferous sequences adjacent to the North Pennine Orefield and with published data for fluid inclusions from North Pennine fluorite. These compositional parameters suggest that the ancient mineralizing fluids resemble modern Carboniferous sediment-derived waters and contain a relatively minor component of granite-derived water. Data for Br and Cl indicate that a significant component of the present day Weardale spring waters was probably ultimately derived from organic-rich sedimentary sequences while data for K, Na and Li indicate the importance of a component derived from a permeable granite aquifer. The Weardale springwaters continue to have ‘mineralizing’ potential, in view of the possibility that they may have precipitated quartz or chalcedony during their ascent.

Keywords: spring water • saline water • metallogenesis • North Pennines • England

Mineralogical Magazine; December 1990 v. 54; no. 377; p. 629-636; DOI: 10.1180/minmag.1990.054.377.16
© 1990, The Mineralogical Society
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