PETROGRAPHIC AND PROVENANCE STUDIES OF HEAVY MINERALS IN SANDSTONES FROM IFELODUN, NIGERIA

Petrographic and provenance studies of heavy minerals in Ifelodun sediment were carried out. Sediment samples from eight locations were obtained from the study area; sieved to allow only sand-size lithology. The result was achieved after subjecting this sieved lithology obtained to analyses using a binocular (transmitted and reflected light) microscope. Minerals were separated in a funnel using bromoform with a specific gravity of about 2.89 (gravity method). The heavy minerals present in lithologic sand units are mainly staurolite, tourmaline, zircon and other opaque minerals including cassiterite. The most dominant non-opaque mineral is staurolite with 27.5% of the total minerals counted in the area. Staurolite is very appreciable in locations AR1 with 60% presence (which is 80% of the non-opaque minerals), AR3, AR5, AR7 and OL15b (each with 30%). OL15b also recorded a better amount of tourmaline (20%); Zircon is better in OL6b with 20% of the heavy minerals available in this location. The source rock predicted is porphyroblastic schists.

Sources of Heavy Minerals of the Neogene Clastics at Bekhme, Northern Iraq

Ten samples were collected from Injana and Mukdadiya Formations, representing 5 samples of fine grain sandstone (F) and 5 samples of very fine grain sandstone (VF). The heavy metals study showed that the opaque mineral recorded the highest percentage in comparison with other heavy metals. While, transparent minerals, including unstable minerals (Amphibole including Hornblend and Glaucophane) and (pyroxene including Orthopyroxene and Clinopyroxene), Metastable minerals including (Epidote, staurolite, Garnet, Kyanite) indicated metamorphic source, Ultrastable minerals (Zircon, Rutile, Tourmaline), Mica group (chlorite, biotite and muscovite). These accumulations indicate that the heavy minerals are derived from mafic igneous and metamorphic rocks mostly, as well as acidic igneous and reworked sediments. Ternary diagram of heavy metals stability showed that they are moderately stable due to the effect of the opaque mineral that have highest attention. Both sandstones for the Injana and Mukdadiya formations are derived from active continental margins. This source rocks may be represented by Taurus and Zagros Mountains.

Heavy mineral distribution in Weichselian drift successions in eastern Denmark

The use of heavy mineral content in Weichselian drift units as a stratigraphic tool has been investigated. A total of 26 heavy mineral analyses of representative samples frorn the four Weichselian kineto­stratigraphic units in eastern Denmark are presented with data on both non-opaque and opaque mineral content. The heavy mineral content frorn inferred source areas has been deduced, partly from published data and partly from studies carried out by the author. The data indicate that heavy mineral analyses cannot be used as a general stratigraphic tool. However, the heavy mineral distribution indicates the occurrence of two distinct Weichselian heavy mineral provinces, a northern and a southern. The reasons why clast petrography studies may supply more reliable stratigraphic information are discussed.