This paper presents new petrological and geochronological data for the ~3.09-2.92 Ga Murchison Greenstone Belt (MGB), located in South Africa’s Kaapvaal Craton, and discusses their geotectonic implications. The MGB is made of three tectono-metamorphic units: the Silwana Amphibolites, the Murchison Unit and the La France Formation. They underwent contrasting clockwise pressure temperature-deformation (P-T-D) histories, and are separated from each other by relatively narrow, high strain shear zones, with a sinistral, transpressive top-to-the-south movement, consistent with the deformation patterns observed throughout the belt.

At Benfontein, near Kimberley, South Africa, three sills of kimberlite intrude Dwyka shales and overlying Karroo dolerite. Each sill results from numerous injections of kimberlite that have consolidated to give the sill a layered appearance. Many layers - show magmatic sedimentation features and cumulus textures, and, although some show in situ differentiation, other layers result from pre-injection differ­entiations The transporting, intercumulus liquid was carbonate-rich and some layers have differentiated to form a carbonate rock composed of the intercumulus calcite; this, on trace element and isotopic data, shows strong affinities with carbonatite. In one of the sills 'one calcite layer has migrated diapirically into overlying layers in.the sill. These sedimentation features, combined with thermal metamorphism of country-rock shales and the presence of quench calcite and apatite, are interpreted as evidence that the kimberlite was injected as a highly mobile fluid, comprising megacrysts of olivine, garnet, pyroxene, mica and picroilmenite in a hot carbonatitic liquid from which olivine, magnetic spinel, perov-skite, apatite, calcite, dolomite, ankerite and quartz crystallised. The evidence that the transportation medium was a warm carbon­atitic liquid is directly opposed to earlier hypotheses proposing that kimberlite is intruded as a cold or plastic paste, and also supports proposals of a genetic link between kimberlite and carbonatite.

Книга виднейшего южноафриканского геолога А. дю Тойта «Геология Южной Африки» представляет классическую сводку, посвященную геологии Южно-Африканского Союза и сопредельных территорий.

В книге детально описывается геологическая история Южной Африки и характеризуется обстановка, определяющая размещение месторождений ряда полезных ископаемых, в частности золота, меди, алмазов, платины, олова и т. д.

Сведения, содержащиеся в книге дю Тойта, несомненно, будут полезны при поисках аналогичных месторождений полезных ископаемых и при. геологическом изучении аналогичных типов структур на территории Советского Союза.

Большой и разнообразный материал, приводимый в книге, снабжен многочисленными, хорошо подобранными иллюстрациями.

Книга дю Тойта представляет большой интерес для широких кругов геологов.