The Cadia Ridgeway deposit is one of a group of porphyry-style deposits discovered since 1992 by Newcrest geologists at Cadia 20 kms south of Orange in the central tablelands of New South Wales, Australia. The Ridgeway deposit lies 500m below the surface, 3 kms north-west of the Cadia Hill open cut mine, and was discovered in November 1996. It is notably rich in Au with an inferred and indicated resource of 44 Mt at 2.6 g/t Au and 0.82% Cu, and is under development as an underground mining operation. <...>

Zoning patterns and zoning truncations in metamorphic minerals in a granodioritic orthogneiss indicate that strain and S-C fabrics in these rocks were produced by dissolution, precipitation, and replacement processes, even at epidote-amphibolite fades metamorphic conditions. The metamorphic fabric is defined by alternating layers and folia dominated by quartz, feldspars, and biotite + epidote. Zoning patterns in most metamorphic plagioclase, orthoclase, epidote, and sphene are truncated at boundaries normal to the shortening direction, suggesting dissolution. Interfaces of relict igneous orthoclase phenocrysts that face the shortening direction are embayed and replaced by biotite, epidote, and myrmekitic intergrowths of plagioclase and quartz. Metamorphic plagioclase grains are also replaced by epidote. We interpret these microstractures to reflect strain-enhanced dissolution. The cores of many grains show asymmetric overgrowths with at least two generations of beards, all oriented on the ends of grains that face the extension direction. We interpret these textures to reflect precipitation of components dissolved by deformation-enhanced dissolution. While biotite and quartz probably deformed by dislocation creep, the overall deformation was accommodated by dissolution perpendicular to the shortening direction, and precipitation parallel to it. These chemical processes must have been activated at lower stresses than the dislocation creep predicted from extrapolations of data from experiments in dry rocks. Thus wet crust is likely to be weaker than calculated from these experimental studies

PAPERS PRESENTED IN SECTION 1
M.N. SOLOVIEVA, V.A. CHIZHOVA, O.L. EINOR, A.D. GRIGORIEVA, E.A. REI-TLINGER, M.V. VDOVENKO.—Review of Recent Data on the Carboniferous Stratigraphy of the USSR
M.N. SOLOVIEVA, О.P. FISUNENKO, N.V. GOREVA, I.S. BARSKOV, V.S. GUBAREVA, A.V. DZHENCHURAEVA, I.I. DALMATSKAYA, E.A. IVANOVA, V.I. POLETAEV, A.V. POPOV, Z.S. RUMYANTSEVA, V.K. TETER-YUK, E.M. SHIK.—New Data on Stratigraphy of the Moskovian Stage
M.N. SOLOVIEVA.—Correction of the USSR General Carboniferous Scale in Connection with Restudying the Moskovian Stage Stratotype and a New Model for the Correlation of the Lower Moskovian Substage     
L.F. GRANADOS, M.N. SOLOVIEVA, E.A. REITLINGER, C. MARTINEZ-DIAZ. — The Bashkirian-Moscovian Boundary Problem in the Asturias (Northwest Spain)
N.J. RILEY, M.J. RAZZO, B. OWENS.—A New Boundary Stratotype Section for the Bolsovian (Westphalian C) in Northern England

PAPERS PRESENTED IN SECTION IV .
L.COUREL, J. DOUBINGER, J.-C. GALL, J. LANGIAUX, Y. PAQUETTE, P. VETTER Relations entre paleoenvironnements et associations vegetales dans ies bassins limniques carboniferes du Massif Central Franfais     
A.A. EL-KHAYAL, R. H. WAGNER.—Upper permian stratigraphy and megafloras of Saudi Arabia: Palaeogeographic and climatic implications     
M. MUNOZ, E. ANCOCHEA, J. SAGREDO, J. A. DE LA PENA, F. HERN AN, J. L. BRANDLE, R. MARFIL.—Vulcanismo permo-carbonifero de la Cordillera Iberica     
J. BROUTIN, J. GISBERT.—Entorno paleoclimatico у ambiental de la flora Stephano-Autu-niente del Pirineo Catalan
P. P. TIMOFEEV, В. V. POLYANSKY.—Facial zonation of early Mesozoic peat accumulation processes within the continental margin of the Tethys Asian Part