The Mesopotamian Sedimentology researches..

Flaky minerals in the recent sediments of the Tigris River, Northern Iraq:

provenance and paleogeographic approaches

Ali Ismail Al-Juboury¹ & Mohsin M. Ghazal²

¹Research Center for Dams and Water Resources, Mosul University, Iraq

² Geology Department, College of Sciences, Mosul University, Iraq

alialjubory@yahoo.com

Abstract

  Mineralogical, chemical, and morphological characteristics of the flaky minerals in the Tigris River sediments, northern Iraq, were determined by using standard petrographic, scanning electron microscope and electron microprobe analyses. The objective is to elucidate the provenance and environmental changes affecting these minerals. Flaky minerals such as muscovite, biotite and chlorite, can constitute up to 60% of the total heavy mineral fraction from recent sandy sediments of the Tigris River at certain locations in northern Iraq. Chemical analyses of the studied white mica indicate that they are of late to post-magmatic and hydrothermal types with close affinities to the mica composition in mica-schist. The studied biotite component was derived from metamorphic rocks rather than from igneous rocks, (i.e. they are not phlogopitic or Mg-rich biotites). Chlorites are of the chamosite type and were derived from metamorphic rocks (mainly schist and slates). The mineralogical and geochemical indicators suggest that these flaky minerals were mainly derived from metamorphic rocks of the Nappe Zone of Turkey and partly from rocks of the Iraqi Nappe Zone as well as from the disintegration of older clastic sedimentary formations within the valley of the Tigris River.

Africa Geoscience Review, Vol. 15, No.2, 56-68, 2008