Quelques réflexions sur le massif basique-ultrabasique du Kizil Dagh, Hatay, Turquie

The Kizil Dagh Massif is one of the major greenstone complex of Turkey. According to Dubertret it is made up from top to bottom of quartzbasalts (sakalavites), diabases (dolerites), gabbros and ultramafics (peridotites, pyroxenites). It is thought to be a single huge submarine flow of Upper Cretaceous age that has differentiated by gravity, with smooth and gradational transition from finegrained basaltic rocks to coarse-grained ultramafics. New observations do not agree with this view. Part of the diabases at least are not lava flows but a sheeted complex of dikes with chilled edges against screens of gabbros. Moreover the transition zone between the gabbros and the peridotites shows a hybrid character. The gabbro injects the peridotite and includes more or less digested ultramafic xenoliths. It is suggested that the peridotite is part of a very deep simatic layer, possibly the Upper Mantle, which underwent partial remelting during the Cretaceous as a consequence of tectonic activity. The resulting basic magma crystallized as the gabbroic phase of the complex. Further magmatic activity led to the emplacement of the sheeted dikes group, which probably are the roots of the pillow lavas volcanoes. The continuation of tectonic movements induced the fragmentation of the peridotite and the partial serpentinization of ultramafic wedges penetrating as "cold intrusions" upper levels of the complex. The analogy between the Kizil Dagh and the Troodos Complex in Cyprus is stressed