Document Details
|
Document Type |
: |
Thesis |
|
Document Title |
: |
Sedimentological and Geomorphological Studies of Caves and Sinkholes in Markaz Adfah Quadrangle, Al Jouf Region, Saudi Arabia دراسات روسوبية وجيومورفولوجية للكهوف والخسوف الأرضية في مربع مركز عذفاء، منطقة الجوف، المملكة العربية السعودية |
|
Subject |
: |
Faculty of Earth Sciences - Petroleum Geology and sediments |
|
Document Language |
: |
Arabic |
|
Abstract |
: |
Caves and karsts are chemically and physically produced features. They are dominated in areas that have been influenced by structural and/or digenetic activities in the past geological times. Distribution, morphologies, and deposits of these caves are very indicative keys for paleoclimatic variability and groundwater interaction with their host rocks.
Saudi Arabia has many caves and sinkholes that are very common morphological features in both carbonate formations and basaltic volcanic flows. In northern and central Saudi Arabia, caves are dominated in Jurassic and Cretaceous carbonate rocks that are exposed along the eastern and northern escarpments of the Tuwaq Mountain.
Al Aqulah, Al Faridah, and Tal Abeed, which are three caves in northern Saudi Arabia near Markaz Adfah, on the borders with Iraq have been investigated for their sedimentology, morphology, and origin. All the studied caves have been formed within the Upper Cretaceous Hudayb Formation of the Aruma Group that is made of limestone and dolomitic limestone. They are distributed along a major jointing and faulting directions in the area of Markaz Adfah that is NE-SW preferred trend. Al Aqulah cave is a small size cave that has a vertical-shaft entrance, and a single chamber. Stalagmites, flowstones, and cave pearls are the main speleothem features in the Al Aqulah Cave. Al Faridah cave is a small sized cave with a collapse-sinkhole entrance and showed several speleothem features such as stalactites, stalagmites, columns, flowstones, rimstones, and bell canopies. Tal Abeed is the largest among the studied caves, and is composed of four collapse chambers. Cement-fillings along the collapsed surfaces are the main speleothem features in this cave.
Petrographic audies of surface and subsurface carbonate thin sections for the host carbonate rocks and the speleothems in the studied caves allowed the recognition of the following microfacies types dolomitic mudstone, dolomitic foraminiferal bioclastic wackestone, sandy dolomitic bioclastic wackestone, dolomitic peloidal packstone, dolomitic packstone and crystalline limetone.
The digenetic processes affecting on the carbonate rock are compaction, micritization, aggrading neomorphism, dolomitization and dedolomitization.
The studied caves are most probably formed by hypogenesis (hypogenetic processes) from uprising gases that are enriched in H2S. This theory is supported by the formation of powdery gypceous crust on the limestone wall, late diagnetic displacive growth of fine gypsum crystals, formation of elephant legs, cupola and the numerous collapses from the walls and ceil of the caves. These caves are modified in a later time, by epigenetic, meteoric water as indicated by the surface formation of buttes, mesas, sinkholes, potholes and speleothems. |
|
Supervisor |
: |
Prof. Dr. Rushdi Jamal A. Taj |
|
Thesis Type |
: |
Master Thesis |
|
Publishing Year |
: |
1437 AH
2016 AD |
|
Co-Supervisor |
: |
Prof. Dr. Mahmoud Ahmed M. Aref |
|
Added Date |
: |
Monday, February 15, 2016 |
|
Researchers
| حسام زهير تركي | Turki, Hussam Zuhair | Researcher | Master | |
|
Back To Researches Page
|