الاشكال الارضية فـي حوض نهر الونـد وعلاقتها بتكتونية المنطقة == Landforms In Alwand River Basin And Their Relation With The Area Tectonics
Author name:
زيد عبد محمود
Supervisor name:
منذر علي طه الخالدي
General topic:
Geography
Specific topic:
Natural Geography
Degree:
Master
University:
University of Diyala - College Of Education For Human Sciences - Department Of Geography
Language:
Arabic
University location:
Diyala
First pages:
10T1348 - p.pdf
Abstract:
تمت دراسة الاشكال الارضية في حوض نهر الوند وعلاقتها بتكتونية المنطقة وما كونه النهر من مظاهر جيومورفولوجية متباينة شكلها عند مروره بالمنطقة المدروسة.تقع منطقة الدراسة في الجزء الشمالي الشرقي من العراق ضمن النطاق غير المستقر , وتغطي ترسبات الزمن الرباعي | The study deals with the geomorphologic shapes resulting from the river - curves in Alwand river and their relation with the area tectonics and the various geomorphologic aspects the river has done when it has passed by the study area.The study area has located in the northeastern of Iraq in unstable zone which is covered with the Quaternary sediments including the river sediments of Pleistocene and Holocene age.In fact , the various geomorphologic processes of the area have been studied as well as the natural features as geology , climate and soil.Moreover ,the morph metric analysis processes of the basins and drainages have been done using the modern techniques as remote sensing and Geographic information systems (GIS)to conduct the study and analyze the basin surface digitally. Also, this study has shown the existence of geomorphologic erosion - sedimentary features, these erosion processes have happened synchronously with the sedimentary processes including pleats and river curves as well as other sedimentary features as river islands ,natural levees and flood plain.The study has shown that the tectonic effect on Wand river causes many curves in its current ,that is the folding process happened because the effect of horizontal stresses which are pushed from the northeastern towards the southwestern caused by the movement and collision of the Arab plate with Iranian Plate. The earth manifestations in the study area caused by two forces : the internal forces represent the earth movement which cause the formation of folds and faults in the area. Such forces cause many geomorphologic phenomena of erosion - structural origin as Cuesta and Dhahr Alhalwf(hog back). The second forces are the external ones which represent the phenomena of erosion origin as caves phenomenon and honey combs phenomenon(Beyout alnahl),and other sedimentary origin as alluvial fans and filled valleys.In addition, the study also,proves that some of the earth movable material as rock fall ,and slab slid ,all these have happened because of the existence of rock discontinuities shown as joints (bc,ac) in the solid or hard sandstones.The desk analysis results have shown the directions of the longitudinal and transversal valleys in the land sat image(2013 TM landsat 5 250000 : 1)and have proved that there is a relation between bending valleys directions and the joints caused by the tectonic processes.This relation indicates that the transversal valleys employ the (ac)joints in their current which are vertical to the axis ply corresponding to the stress direction that causes the fold ,whereas longitudinal valleys tend to employ the (bc)joints corresponding to the axis ply which are considered as release joints happened after the calmness of the stress causing the folding.Through the positional studies of such joints in the field stations ,it has been proved that most of the joints in these stations take two directions : the first is the vertical to the fold axis between (050 - 060), and the second type is the joints which are parallel to the fold axis between (121 - 130).Some of the second type joints are considered as extension ones whereas the others are conjugate.Studying those joints and their directions shows that the study area has passed by a number of events. These events are horizontal compressive stress its direction is northeastern - southwestern followed by extension stress happened later. Then, the conjugate joints which are (Hko) type (a) exposed to great effect of whose direction is northeastern - southwestern causing the folding process.but the other joints have shown that there is no relation between the joints and the fold process but the reason is some different tectonic development which comes later. These joints have played an important role in delimitating the general current of Alwand river and its directions.
