Apophyllite and Other Zeolite-type Minerals from the Whin Sill of the Northern Pennines

B. Young, A. Dyer, N. Hubbard and R. E. Starkey
British Geological Survey, Windsor Court, Windsor Terrace, Newcastle upon Tyne NE2 4HB
Department of Chemistry and Applied Chemistry, University of Salford, Salford, M5 4WT
122 Cordery Road, Evington, Leicester LE5 6DF
15 Warwick Avenue, Fringe Green, Bromsgrove, Worcestershire B60 2AH

Abstract: Apophyllite, analcite, chabazite, prehnite and stilbite are described from pectolite-, chlorite-, calcite- and quartz-bearing veins and joint coatings in the late Carboniferous quartz dolerite of the Whin Sill of the northern Pennines. These veins represent the final hydrothermal stages in the sill's emplacement and are not related to the widespread lead-zinc-barium-fluorite mineralization of the northern Pennine orefield. Thermogravimetric studies of apophyllites from the two Whin Sill occurrences reveal that at one locality the minreal is fluorapophyllite, at the other hydroxyapophyllite.

Keywords: analcite • apophyllite • chabazite • northern Pennines • pectolite • prehnite • thermogravimetric analysis • Whin Sill

Mineralogical Magazine; June 1991 v. 55; no. 379; p. 203-207; DOI: 10.1180/minmag.1991.055.379.08
© 1991, The Mineralogical Society
Mineralogical Society (www.minersoc.org)