4:68 Scientific Intelligence. 



beds, heretofore referred to the Ft. Pierre, really belong to the 

 Benton shales and accordingly the limestones and chalk of the 

 Inoceramus beds, as developed in Iowa, are not to be correlated 

 with the Niobrara farther west. They represent instead that 

 portion of the Fort Benton sub-stage exposed in the ' Oyster 

 Shell Rim ' of the Black Hills." The principle of cooperation 

 expressed in the organization of the survey, is further carried out 

 in the formation of a joint commission to investigate the clay 

 resources of the State. This commission is composed of the Iowa 

 Brick and Tile Makers' Association, Iowa Engineering Society,, 

 the State College, and the State University. The results of their 

 work during the year is given in Dr. Beyer's appended report on 

 the Mineral Production of Iowa, in 1899. h. s. w. 



3. Cleopatra's Emerald Mines. — An account is given in the 

 November number of the Geological Journal of an expedition 

 led by Mr. Donald A. Mac Alister to the so-called Cleopatra's 

 Emerald Mines in the neighborhood of Jebel Sikait in Northern 

 Etbai. The locality is situated nearly due east of Edfu, and some 

 fifteen miles in a direct line from the Red Sea, between 25° and 24° 

 30' N. Lat. The place was reached by the expedition starting from 

 Daraw. The mountain, Jebel Sikait, has an altitude of 1800 feet 

 above sea-level and commands an extensive view over the wild 

 and desolate surrounding country. 



The emeralds occur in mica schist and talc schist, which rocks 

 occur over a large area. The mica schist is in some cases highly 

 micaceous, looking like a finely bedded, contorted sandstone, and 

 again contains very little quartz. In some cases the rock is much 

 hydrated, passing into a soft, powdery rock. Tourmaline, garnet, 

 actinolite, chrysolite are common minerals of the locality. The 

 schists of Jebel Sikait are inclined at an angle of about 45°, and 

 overlie gneiss on one side, while on the other they are inclosed by 

 a tough, green serpentine, of which the upper part of the 

 mountain is composed. The search for emeralds was carried on 

 two thousand years ago very extensively, a large number of 

 mines being opened and extensive workings being carried forward. 

 The author remarks in regard* to this subject: 



" The mining is of a most primitive character. The ancients 

 simply excavated, in the likely emerald-bearing schist, a network 

 of long and very tortuous passages just large enough to allow of 

 the body being dragged through, and only in a very few cases 

 was any attempt made at stopping (or excavating) the entire 

 seam. It has been suggested that the passages were made small 

 on account of the absence of timber, suitable to be hewn into 

 supports, which would be necessary to prevent collapses in the 

 case of larger excavations. So small are the openings, that a 

 casual observer would not notice the existence of a mine at all 

 but for the gray debris thrown out at the mouth. Along the 

 schists at Sikait alone we visited considerably over a hundred 

 mines, some of which took more than an hour to crawl through. 

 That these mines have been worked at widely distant periods, is 



