Engineering Geological Mapping of the Greater Makkah Al Mukarramah Area
Abdulaziz M. Solami, Gabel Z. Al Barakati, Sultan B. Al Bahloul, Bandar A. Al Tunsi, Waheed M. Baamer, Ali B. Al Balkhi,Turki E. Sehli, and Mohammed S. Theeban
The growth of the Holy City of Makkah demonstrates a unique example among the birth of cities in the world. It flourished in a desert area, having no reliable source of water, food, or any other natural resources. With the continued growth of the city of Makkah, the area around the Holy Mosque became heavily populated and the density of buildings is increasing every year. The need for additional residential areas became necessary as a result of a continuous increase in population. The city has expanded significantly into the surrounding open lands. However, a number natural constraints are imposed on its development by the physical geography of its site. These obstacles are aligned along a series of narrow wadis flanked by bare steep-sided mountains and hills. The study area is located in the southern part of Hijaz region on the western side of the Arabian shield, which is dominated by different types of igneous, metamorphic and sedimentary rocks of Precambrian and lower Paleozoic era. In addition, there are subordinate sedimentary rocks and basaltic lava flows of Tertiary and Quaternary age. The dominant structural trend is northeast to north-northeast and reflects three major phases of Precambrian deformation, and Tertiary faulting. The first deformational phase affected the Zibarah group, the second phase affected the Samran group, and the third affected the Fatima group. The most prominent northeasterly trending structures are the Fatima structural zone. The objective of this research is to study the engineering geological aspects of the Holy City of Makkah, with emphases on geologic, geomorphological and hydrological conditions and the engineering properties of soils and rocks. The information should be of value for land-use and urban planning as well as for engineers, planners, and designers.
The scope of the work is conducted as follows:
1- Geological mapping of the area at a scale of 1:50,000 using aerial photographs and satellite images. Rock and soil types and the existing structures in the area were studied to delineate places considered unsuitable for construction purposes.
2- Assessment of geohazards conditions: define flood areas, water resources and slope stability problems.
3- Classification and description of rocks and soils for engineering geological mapping.
4- Locating sites for construction materials.
5- Producing an engineering geological map of future urban planning.
6- Recommendations and relevant data for foundation problems.
Solami, A.M., Al Barakati, G.Z., Al Bahloul, S. B., Al Tunsi, B.A., Baamer, W.M., Al Balkhi, A.B., Sehli, T.E., Theeban, M.S., 2006, Engineering geological mapping of the Greater Makkah al Mukarramah area: Saudi Geological Survey Open-File Report SGS-OF-2005-17, 48 p., 26 figs., 14 tables, 2 plate., 2 apps. (Appendix A2 bound separately).