HE RELA TIONSHIP BETWEEN GRAIN SIZE AND CARBONATE MINERALS IN REEFAL SEDIMENT OFF JEDDAH CITY, RED SEA', SAUDI ARABIA

THE RELA TIONSHIP BETWEEN GRAIN SIZE AND CARBONATE

MINERALS IN REEFAL SEDIMENT OFF JEDDAH CITY, RED

SEA’, SAUDI ARABIA

BY
AHMEDE.RIFAAT* AiVD HAMADA.AL-WASHMI
*Faculty ofivlarine Science 80207, King AbdulAziz University, Jeddah 21589, Saudi Arabia
Keywords: reefal-sediment-carbonate-minerals-red sea.
ABSTRACT
The carbonate sediments off Jeddah City. Saudi Arabia are of
biogenic origin and are contributed by coral debris. molluscan shells.
coralline algae and fomlainifera. The relationship between sediment
grain size and its carbonate minerals is studied and discllssed. The
sediments were analyzed for mean grain size. calcium. magnesium.
strontium. and their content of carbonate minerals. The study showed
that there is a strong relation between mean grain size of the sediment
and its carbonate minerals. Aragonite is strongly correlated with fine
sediments. High-magnesian calcite is inversely correlated u’ith both
aragonite and fine sediments. Low-magnesian calcite showed no
distinct distribution pattern. The aragonite fine sediments may be
derived
and
magnesian
foraminifer
by
calcite
inorganic’organic
shells.
coarse
Low-magnesian
sediments
precipitation
are
calcite
contributed
of lime
is detrital
mud
by algal
in
The
origin:
debns
highit
is most probably derived from the Pleistocene sediments of the coastal
plain.