The melilite-bearing skarns of Cornet Hill (CH) and Upper Cerboaia Valley (UCV), in the Apuseni Mountains of Romania, occur at the contact between monzodiorite bodies of Ypresian age (Paleocene) and Neojurassic calcitic marbles. Typical wollastonite -grossular -diopside endoskarns are separated from exoskarns (tilleyite and spurrite or wollastonite at CH, wollastonite only at UCV), at most places, by a melilite-rich rock, in which veins and vein-like zones of recrystallization are composed only of idiomorphic melilite crystals reaching 15 cm across. Titanian garnet and wollastonite are the principal minerals associated with melilite (and also monticellite, perovskite, vesuvianite, cuspidine, spurrite, tilleyite, calcite, hydroxylellestadite, hydrogrossular and other minor alteration-induced minerals). A different association that includes aluminian diopside and grossular occurs (1) as veinlets in the marble close to the skarns and (2) as relict inclusions in endoskarns. From the geometrical relationships of the zone sequences and the veins, the textural features of the mineral associations and the inferred conditions of fluid-mineral equilibrium, these mineralogical peculiarities are interpreted as resulting from the superposition of two main stages. Firstly, there was circulation of a comparatively CO 2 -rich fluid formed the early aluminian diopside -grossular endoskarns, with depletion in Si (and Fe, Na, K) and inert behavior of Mg, Al, Ti. Then, a high-temperature (750°C) fluid circulated on both sides of the contact between marble and endoskarns, and developed the melilite-rich, titanian-garnet-bearing rocks partly at the expense of previously formed endoskarns, and spurrite or wollastonite (CH) or wollastonite (UCV) exoskarns at the expense of marble. The pressure of CO 2 was very low, less than 26 bars at UCV and 16 bars at CH, with a H 2 O pressure less than 750 bars. Not only Si and Ca were mobilized, but also Mg, Al and Ti, leached from the endoskarns and deposited in the veins and the nearby part of exoskarns. This stage, which occurred in the temperature range corresponding to the end of the crystallization of plagioclase in the monzodiorite, has pegmatitic chemical and textural features. The main flow of fluid ended with the development of tilleyite partly at the expense of spurrite and wollastonite at CH, and local high-temperature (about 710°C) recrystallization of the zonation, mostly in veins, especially in the endoskarn-exoskarn boundary, but also within the endoskarns. A monticellite -gehlenite association appeared in the melilite-rich rocks, later followed by vesuvianite, whereas in the endoskarn, vesuvianite developed together with coarse-grained wollastonite and grossular.

We describe the occurrence of high-temperature, spurrite-, tilleyite-and gehlenite-bearing skarns from Cornet Hill, part of the Metaliferi Massif, Apuseni Mountains, Romania, and the main mineral species developed in these rocks. The host skarns are developed at the contact between a quartz monzonitic -monzodioritic body of Paleocene -Ypresian age and Tithonian limestones. The primary mineral assemblage mainly consists of tilleyite, spurrite and gehlenite, with various amounts of garnet and wollastonite; perovskite, monticellite and hydroxylellestadite are present but scarce. The skarns have clearly undergone a late metasomatic event, which produced, for example, diopside veins cross-cutting tilleyite, spurrite, and gehlenite, and small masses and veins of vesuvianite replacing gehlenite. Subsequent hydrothermal and weathering overprints on the primary assemblages resulted in the formation of three secondary parageneses: (1) an early hydrothermal one that includes scawtite, xonotlite and hibschite, (2) a late hydrothermal one that includes 11 Å tobermorite, riversideite, thomsonite, gismondine, aragonite, and calcite, and (3) a weathering paragenesis that includes plombièrite, portlandite, and allophane. The main properties of these mineral species, as revealed using chemical, optical and X-ray powder analyses, are reported here. We document the first occurrence of plombièrite, tobermorite, riversideite, portlandite and allophane in Romania.

This paper describes the geology, tectonometamorphic history and geochronology of part of the northern flank of the Neelum valley in Azad Kashmir, NE Pakistan. Metamorphic crystalline rocks in this area belong to the Lesser and Higher Himalayan Crystalline complexes. Geological mapping of about 1500 km2 confirms the presence of three main tectonic units characterized by similar lithostratigraphic sequences but with different tectonometamorphic histories. Whether these tectonic units belong to the Lesser or Higher Himalayan Crystallines depends on the, still controversial, position of the Main Central Thrust. A tectonic model, involving syn-convergent exhumation, is suggested that is consistent with new petrographic and geochronological data, and with a revised interpretation of the Main Central Thrust.

Between 1971 and 1986 the scheelite deposit of Salau, located in the French Hercynian Pyrenees, produced 930,000 metric tons of ore with 1.50 percent WO3 (13,950 metric tons of WO3).The skarn deposit is hosted in a Devonian carbonate and partly detrital series intruded by a late Carboniferous stock. In the Devonian series (the lithostratigraphy and geochemistry of which is described in some detail) a unit of so-called "Barregiennes" (i.e., rythmic alternations of limestones and silts) appears to be very favorable for extensive development of skarns and overprinted ores.The Hercynian orogeny involved polyphase deformation, regional metamorphism of greenschist facies, and late intrusions of granite-granodiorite. Deformation included two coaxial stages of tight isoclinal folding and one important later stage which partly controlled the intrusion of the granodiorite stock, followed by three stages of brittle deformation. Ore deposition is related to faulting stages 0 and 1 and orebodies are cut into slices by stage 2 reverse faults.The Salau intrusion includes various rock types belonging to two slightly different calcalkaline trends. One of these trends, characterized by its low K contents, is unusual in the Pyrenees. The local shapes of the intrusion, apophyses and embayments, are important controls of the orebodies. After isochemical contact metamorphism, the skarns and ores developed in two mainstages related to the infiltration of two quite different types of fluids. During the first stage (540 ø-450øC), anhydrous skarn formation was followed by an intergranular development of pyrrhotite-scheelite-quartz-calcite in equilibrium with the earlier hedenbergite. The resulting tungsten grade is uneconomic. The associated fluids, probably of magmatic origin, had a high salinity. In the second stage (450ø-350øC), no new skarn formed; transformations of the silicate rocks are observed. A first substage of epidotization was followed by the development of intermediate grossularite-almandine-spessartite garnet and finally by the main ore stage 0361-0128/89/959/1172-2853.00 1172 SALAU SCHEELITE DEPOSIT, FRENCH PYRENEES 1173with scheelite, pyrrhotite, arsenopyrite, and other sulfides with some gold. Two types of fluid inclusions are found in this stage; one is similar in composition to the first stage, the other is characterized by low salinity and high CO2 and CH4 contents.

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