Fazel Iranmanesh, Mehran Maghsoudi, Ebrahim Moghimi, Mojtaba Yamani, Amir Hossin Charkhabi,
Volume 16, Issue 41 (5-2015)
Abstract
Deltas of the most important morphological units are a tremendous effect on agricultural activities, mining, coastal management and etc. Despite appropriate soil and water resources deltas, are influenced by environmental phenomena such as climate change and sea level changes. The effect of these changes will appear on physico-chemical, mineralogical deposits. This study was conducted to analyze the Karkheh delta depositional environments based on the chemical characteristics of ancient sediments. Depositional environments and locations of core were identified using digital data processing, geomorphology mapping and initial visit of the area. The coring was carried out with rotary drilling machine and continuously to a depth of ten meters in jofeir and Rofayeh. Among The cores, 20 samples were selected for mineralogical and chemical tests. Differences in chemical and mineralogical characteristics revealed at least three major discontinuities exist between sedimentary layers to a depth of 10 m. In addition, thickness and type of the sediment are not same conditions and it changes depending on the stability of depositional environments. Increasing of Mg / Ca, magnesium and salinity, and reducing of clay particles, show Sedimentary environments trend is toward dry conditions and high energy environments at depths from 10 to 5 meters. In contrast, the depth of 5 to 4 and 3 to 0 meter this trend towards more humid climate and low energy environments. Therefore, it is concluded that the depositional environment of the Karkheh River delta at the upper Holocene is not constant, and this has led to changes in the delta.
