Crushing of the older rocks is almost everywhere strongly evidenced, but faulting is difficult to trace except in the sandstone areas, where it is strongly marked. The presence of clearly defined overthrust faulting in the Abraq area shows that tangential earth movements, so rare in this part of the world,[46] have not been altogether absent. =Mineral Products.= The mineral resources of this part of Egypt are not of very great importance, owing partly to its inaccessible situation and desert character. Gold and copper ores occur in places; other localities contain beryl and peridots, while others, again, bear iron ores, gypsum, sulphur, steatite, asbestos, and magnesite, and good building stones abound over large areas. The presence of ruins and excavations at places like Hangalia, Sikait, Zabara, Romit, and Darahib, are evidence of mining activity in the past, but the mean nature of the accommodation for the workers, and the presence of old stone hand mills where gold was the thing sought for, confirm the statement of Diodorus[47] that the mines were worked by miserable convicts. In recent years much prospecting has been done to test whether the ancient mines could be developed and made commercially productive under modern conditions. In the case of many areas, including that round Darahib, the mines of which are believed to be those referred to with a map in the Turin papyrus of the Nineteenth Dynasty,[48] the prospecting licences have been surrendered to the Government because the results were unfavourable. In a few other cases prospecting is still being carried out, and in three localities the results have been sufficiently encouraging for exploitation to be undertaken. The following tables, compiled from information supplied by the Mines Department, give particulars of the prospecting licences and mining leases at present (1912) held within the area described in this book:— PROSPECTING LICENCES.