274 



iJEPOiiT — 1884. 



. iim 



Hiiiii) 



* 3. A geological vcconnaissanco along tlie line of route through the 

 districts of Sinai, Akabah, and the Wudy ol Arabah, including the follow- 

 ing particulars : — 



' (a) Collections of fossils fi-nm tho Wady Nash limestone, in addition 

 to those already niaiie by Mr. IJauorman and Colonel Sir C. W. Wilson. 

 These fossils (which are bonig cxi.niined by Professor Sollas) go to show 

 that this limestone is of carboniferous age: the Wady Nasb limestone 

 was found to continue over a considerable region north of Mount 

 Sinai, and was again recognised amongst tho mountains of Moab on the 

 east side of the Salt Sea in the Wady el Hessi. As this limestone rests 

 upon a red sandstone foundation, this la^^ter may also be as; .ned to be of 

 the same geological age, and therefore cannot be the repi'es. 4ve of the 

 " Nubian sandstone " of Russeger, which (a^. Professor Zittei shown) 

 is of cretaceous age. Ipropo.se to call tliis formation, tlieretL.c, "tho 

 Desert Sandstone."' It forms with the limestone a strip along th' borders 

 of the ancient rocks of paUeozoic or archaian age, and is about I'lO feet in 

 average thickness : tiie base is generally a conglomerate. 



' (6) Above the WadyXasb limestone is another sanistone formation, 

 of whicli a largo portion of tho Debet er Ramleh is formed. It is laid 

 open in the Wadles /elegah, Biyar, &c., and along the mountains of Edom 

 and Moab. Out of this rock have been hewn the ancient temples, tombs, 

 anc. dwellings of Petra and the Wady Musa. It stretches along the 

 southern escarpment of the Tih plateau, and forms tlie base of the 

 limestone clIH's along the margin of tho Wady el Arabah as far north 

 as Ncgeb cs Salni. Tliis sandstone formation is soft, red, or beautifully 

 variegated, and is in all probability of cretaceous age, and ilierefore the 

 true representative of the '' NubiaTi sandstone " of Russeger. It will 

 thus be seen that tbere are two red sandstone formations, one below, the 

 other al)Ove the carboniferous limestone of the WMy Nasb. 



' (c) The geological structure of the Wady el Arabah was examined 

 throughout a distance of 120 miles from south to north. That it has 

 been hollowed out along the line of a main fault, ranging from the eastern 

 shore of the Salt Sea to that of the '" -If of Akabah, was clearly deter- 

 mined; and the position of the fault .^elf wa': made out and laid down 

 on the map ' in t^ix or .seven places, one being about ten miles north of 

 Alcabah, anothi'r near the watershed, in which places the limestone of 

 the Tih (cretaceo-nummulitic) is faulted against the old porphyritic and 

 metamorphlc rocks 1 give on the next page two sketch sections to illas- 

 tratc the structure at these points. 



* Tliei'c are immerous parallel and branching faults along tho Arabah 

 Valle}', but there is one; leaduig fracture running along the base of the 

 hJdomito mountains, to whicu the others are of secondary importance; 

 this may be called '• thcs Great Jordan Valley fault." Tlie relatior.s of 

 the rocks in the Glior and Jordan Valley have already been shown by 

 Lai'tet, Tristram, Wilson, and others, to indicate the presence of a largo 

 fault corresponding with the line of this rennirkable dejiression, and tho 

 author considers the fracture he has observed in the Arabah Valley to be 

 continuous with that of the Jordan. 



' ((/) The ancient rocks which form the floor either of tho Desert or 

 Nubian sandstone foi'mations consist of granite, gi'eiss, porphyries, and 

 more rarely metaniorphic schistose rocks — together with volcanic I'oeks, 



' Tlu; mni> iis(m1 was an cnlari^ed plan fnmi Hmitii and Urovo's Ancient Atlas 

 (J. Muniiy'' 



5 ^ .*' * 



