The principal theme of this three-and-a-half-day conference (13–17 December 1976) at Durham University was the value of fluid inclusion studies in investigations into the origin of mineral deposits and rocks. Other sessions covered opaque mineralogy, studies on natural and synthetic sulphide systems and various other aspects of ore geology. For this conference the Mineral Deposits Studies Group joined forces with the Applied Mineralogy Group of the Mineralogical Society. There was also official participation by representatives from the Groupe Inclusions of the Société Française de Minéralogie et de Cristallographie and from C.N.R.S. centres at Paris and Nancy.
Fluid inclusion papers were mainly concerned with studies of economic mineral deposits. It was stressed (Deicha) that they can now yield valuable data on the genesis of minerals formed over the full range of temperatures from magmatic (Althaus) to sedimentary (Sabouraud et al.). Four papers were concerned with fluid inclusions in fluorite. In one, P. J. Rogers showed that fluids in Derbyshire fluorites have similar salinities to those from the northern Pennine orefields, but a lower K/Na ratio. In another, F. W. Smith demonstrated how homogenization temperatures could be used to reconstruct the distribution of isothermal surfaces in veins so as to outline flow paths and calculate cooling gradients. There have been far too few intensive investigations of this sort on single veins. Such studies combined with Conolly diagrams could become important exploration tools and it is to be hoped that other workers will follow this lead. In work on other vein deposits