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The deterioration of natural stone monuments is subject to different external reasons that take place through different weathering factors, in addition to other several factors concerning the stone itself “internal reasons” mainly pore structure and permeability index. All of these factors lead to the formation of altered surface layers, then damaging the original stone components. Here, red weathering, one of the most aggressive deterioration forms affecting one of the most famous archaeological sites in the world (Un-finished Obelisk in Aswan) was investigated and evaluated through different analytical techniques. Binuclear Microscop and SEM were used to evaluate the optical and morphological features of the highly deteriorated samples. Moreover EDX and XRD techniques were used for defining the chemical and mineralogical compositions of collected samples. Lastly, ArcGIS program was used as a tool for simulation description of red weathering symptom to evaluate their aggressive roles in the deterioration processes affecting the object. Our results proved that there are some changes in the granite regarding essential elements with high percentages of SiO2, Al2O3 and Fe2O3 especially in affected zones. In addition, increasing the weathering products, such as, microcrystalline matrix and salty products (tosudite, kaolinite, illite and gypsum) defined and calculated both in affected and none affected areas. Finally, calculation of the etching volume of sample and corroded percentages were conducted.

The objective of this study is to investigate the groundwater influences on sandstone in Horus temple, in addition to studying the deterioration processes affecting the temple building materials. Specific investigations were carried out to measure the groundwater features and quality both inside and outside the temple to evaluate the resulted deterioration processes. Our results argue that the temple was built on a hill of silt and clay belonging to the Cretaceous Era; it rises on the south part of the Nile valley far from the Nile for about 1200 m. Groundwater quality is strongly influenced by the dominating minerals and stone aquifer affected by three major water sources. The temple faces many deterioration processes due to the effect of groundwater characterized by high salinity index. These processes led finally to two main mechanisms, (the first related to micro-deterioration and the second resulting from structural defects). These mechanisms affirmed that the stone building materials were highly characterized by weakness, fracture, disintegration, cracks and crevices collapsing of their components. Furthermore, the dominating major salt species are halite, gypsum, sylvite and thenardite and minor quantities of carbonates and bi-carbonates, in addition to phosphate as or trace constituents.

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