TITLE:
Origin and Distribution of Heavy Minerals in the Surficial and Subsurficial Sediments of the Alluvial Nile River Terraces
AUTHORS:
Magboul M. Sulieman, Ibrahim S. Ibrahim, Jamal T. Elfaki, Mohamed S. Dafa-Allah
KEYWORDS:
Alluvial Nile River Terraces, Khartoum North, Petrography Microscope, Aeolian Sediments, Ethiopian Plateau
JOURNAL NAME:
Open Journal of Soil Science,
Vol.5 No.12,
December
17,
2015
ABSTRACT: Origin
and distribution of the heavy minerals of surficial and subsurficial sediments
has been investigated in the alluvial Nile River terraces, Khartoum North,
Sudan. Heavy mineral assemblages in the very fine sand fraction (0.063 - 0.125
mm) of 10 sediment samples were identified using petrography microscope.
Results of descriptive statistical parameters revealed that most sediments
samples belonged within very poorly sorted to extremely poorly sorted, strongly
negative skewed to strongly positive skewed and mesokurtic to very leptokurtic.
The quartz was the dominant in the opaque minerals in all sediments. The
non-opaque heavy minerals were dominant by zircon, tourmaline, rutile, garnet,
sillimanite, and andalusite. Results revealed that the ultrastable minerals
(zircon, tourmaline and rutile) were found in all sediments with range from (2%
- 47.36%, 2.08% - 29% and 3% - 24.99%), respectively. Garnet, sillimanite and
andalusite were also found with range from (5% - 67%, 1% - 9.09% and 1% - 50%),
respectively. Heavy mineral assemblage indentifies sources that are not bounded
to the local origin. The proportion and presence of heavy minerals from outside
source rocks indicated relatively strong reworking of zircon sand from the
outer-shelf to inner-shelf as well relatively long distance of transport.
Fluvial and Aeolian sediments were the dominant environments in the investigated
area. We conclude that most heavy minerals in the study area are originally
derived from gneisses and schist metamorphic rocks and some igneous rocks of
the Ethiopian plateau.