A study of mineralisation in the Jew limestone, Rookhope borehole.

The nature and distribution of sulphide and non-sulphide epigenetic mineralisation in a section of the Jew Limestone, Rookhope Borehole, are discussed. The pre-mineralisation textural nature and mineralogical and elemental composition of the host rock and the modification of such under the influence of the hydro thermal activity are considered as well as the trace element distribution pattern in the host rock, geothermometric aspects of the mineral assemblage, and the attitude of the mineralisation. Certain aspects of the physical chemistry of the system are discussed and limits imposed on the composition of the depositing fluid at various stages during the mineralising process. Unusual features of the sphalerite and the epigenetic carbonates as revealed by electron microprobe analysis are emphasised. Several of the results of the study are not in agreement with previously-published data on the Jew Limestone in particular and the Northern Pennine mineralisation in general.