مقارنة التركيب المعدني لمفصول الرمل في ترب جبسية مختلفة من ترسبات دجلة و الفرات

الملخص EN

Sand minerals have been diagnosed for the soils of Tigris and Euphrates rivers located in the arid climatic environments of Iraq, a transect of six pedons distributed by three pedons for Tigris river deposits located within Salah El-Din province and three other pedons for the deposits of Euphrates River within the province of Najaf.

Tests show of mineralogical analysis showed of the very fine sand in soil study dominant of the light minerals, as attained their percentage in Salah al-Din province 87.90-98.33% and an average more than 94% , while its quantity in Najaf province ranged between 93.66- 98.66% and an average of more than 96% In both, the dominance of evaporators then it is followed by carbonates and quartz minerals, while other minerals were ccording to the following order: Rock fragments > Chert > Feldspars minerals >others showed values of the weathering index for light meinerals using quartz soil content on their feldspar content that they ranged between 2.50-3.88% in Salah El-Din pedons, where as for the Najaf pedon, it was between 2.12-7.16% the values of this indicator showed a relative increase with depth in the cultivate pedons than those that are non cultivate This indicates the effect of the cultivation factor on the components of the surface horizons to a greater degree than the subsurface horizons, where as the percentage of the heavy minerals ranged between 1.34-7.20% and an average of 3.35% , while the results showed the heavy minerals of the very fine sand fraction that was diagnosed as containing mainly of opaque minerals then followed of Mica minerals, Celestite epidote and Zircon.

TO note the weathering intensity of heavy minerals (resistant minerals to weathering /easily weathered minerals) the ratio between (Carnet + Tormaline/ Amphibole + Pyroxene) was used as a weathering index.

Percentage of the index minerals which expresses the total proportions of resistant minerals (Carnit + Zircon + Rutile + Tourmaline), was calculated according to the percentages of weathering evidence according to the increase in surface horizons.