| الملخص | Abstract
This study aimed to throw the light on the geological factors and weather conditions granted to produce the Terra rossa in Wadi Kersy area in Jabal Sinjar in order to evaluate its mineral constituents and define its sources and estimate its quantities.
This study depended on the field reconnaissance for three selected sites and pick eight Terra rossa channel samples for grain size and chemical analyses, and X-ray deffraction, and also to study the petrophysical properties and microscopical tests for the rock fragments mixed with soil.
Wadi Kersy considered as one of strike valley which is distingiushed by the presence of many rock terraces, which some of its cliffs covered with thin mantl of Terra rossa, in form of pseudo breccia and heterogenous in distribution.
This study decleared that the rock cliffs of moderate slop in Wadi kersy exposed to a chemical dissolution during the rainy periods in Pleistocene, before about (2)m.y. In that time the rain water filtered through the testonic joints and the secondary pores was acting in the dissolution of carbonate materials in Sinjar Formation rocks and altered it to brown-reddish brown colour soil, loose, dry , unlayered , immature, cover some of Wadi Kersy cliff with thin thickness about (0.02-0.50)meter and heterogenous distribution.
The chemical analysis and X.R.D. and microscopical tests to the rock fragments showed that Terra rossa in Wadi Kersy is a production results of chemical weathering for the fossiliferous microsparite limestone which content Calcium Oxide, Aluminum Oxide& Iron Oxide (Geothite, trace of Hematite and Jarosite) wich is derived from the decay of limestone as insoluble residue in its present place. It is of no economical importance that’s due to the shortage concentration of Iron Oxides which is ranging between (1.6-9.9)% and with an average (3.64)% in addition to its small quantities and heterogenity in vertical and horizental sepration. | |
