The Granitic monumental objects under consideration had been located on the site of Pharos (between 2nd century BC and 14th century AD), but had fallen into sea water after serial destruction by earthquakes. The site is now underwater just off the shore of Alexandria. At the end of last century many of these objects were lifted out from underwater and stored or exihibited at different places in Alexandria City. To date, the investigated monumental objects have passed through three stages of deterioration: 1) when they were on the coast of Pharos Island, 2) after the collapsing of the Lighthouse, and 3) after lifting some objects from underwater. The present work mainly aims to record the different deterioration forms that resulted from the degradation of the Lighthouse granitic monumental objects, which had suffered from several deterioration factors. Two major types of deterioration forms have been recorded; non-visible (nano-scale, < mm) forms and visible (micro, meso, and macro-scales) forms. Recording of the non-visible deterioration of the studied granitic objects has been achieved by using a polarizing microscope and scanning electron microscope (SEM) together with XRF and XRD. While the visible forms have been recorded macroscopically. The non-visible deterioration phenomena are represented by degradation of feldspars and mica (biotite) to clay minerals and the presence of the micro-cracks and their filling. On the other hand, cracks, exfoliation, scaling, contour scaling, granular disintegration, rounding, roughening, missing parts, perforation, pitting, deposit, coloration and biological impacts are the main recorded visible forms. The deterioration phenomena are investigated and recorded according to the definition of each deterioration phenomenon. The mechanisms of the recorded weathering phenomena are discussed in detail.
Akarish et al. (Mon,) studied this question.