* Tlie elevationa were determined by the officers of tha Ordnance Survey of Sinai. The height of Jebel MQsa, calculated by .Mr. R. Laurence from Suez by aneroid, waa 7685 ft., and from 'Akabah was 7695 ft., both over those of the Ordnanci Survey, but probably less reliable. (See Hull, llauiU Seir, 48).
GEOLOGY OF PALESTINE
GEOLOGY OF PALESTINE L-;3
elusion that Palestine presented conditions unsuitcd to till- ik'position of strata during' tliesu ])eriod9 ; or else that beds belonging to one or more of these periods liaving been deposited, had afterwards been removed by denuding agencies ; but this is the less probable supposition.
The general succession of the formations present In Palestine is as follows in df.scending order : —
Geological Forwattoss. f\. Sandhills and I'tsert sands. Retmt . • {^ Alluvial deposits of the Jordan and other ^, streams.
Raised sea-'>caches ; sand and gr&vel with shells.
From Pluvial J 2. Calcareous marls, saliferous beds, sand and to Pliocene, l gravel torniing terraces in the Jordun-
Arabah VuUey ; old Lake beds in Arabia- Petrya.
Uore Recent Volcanic
rocks .
Eoceiie .
Loiter Carbon- jl ijeroua , is
Voleame Seria -j
Archtxan
Basal:., dolerite, tuff, etc.
Calcareous Sandstone of Phili9tia(T), Nunimnlite limestone series.
Cretaceous limestone with marls, etc ' Nubian sandstone.'
Wady Nasb limestone. . Desert sandstone and conglomerate.
Agglomerates, beds of lava, ashes, and tuff of indeterminate age.
Granitic gneiss, granite, homblendic and other schists ; dykes of diorite, porphyry, V etc
(a) Archrean. — These rocks are found only amongst the Sinaitic and Edomite mountains, and are considered to be the representatives of the crystallij e masses which come to the surface from benei:;li the Nubian sandstone at the First Cataract of the Nile. They lie at the base of all the forma- tions in this part of the world, and have been re- ferred by Friua.s to the Archsean period.* They consist of homblendic, chloritie, ancf t.alcose schists of the Wadis Nasb, Sarabit, and Feirftn, underlain by reddish and greyish granite and gneiss. These rocks are penetrated by innumerable dykes and ridges of red felstone-porphyry, diorite, and basalt, of later, but indeterminate, age ; except that they are more ancient than the Nubian sandstone of the CretiKcous period, or the Desert sandstone of the Carlioniferous.
(6) VolcJtnic Series. — To the period of these dykes may be referable the stratified lavas, tufl's, and agglomerates of the Wadj' Haroun and Jebel esh- Shomrah (or Shomar) which form the basement beds ea-st of the Dead Sea,tand are overlain' by the Desert sandstone. Magnificent sections of ag- glomerate and igneous intrusions are laid open in the Wady el-Hessi, near es-Saheh, but their age is indetennmate beyond the fact that they are later than the Archsean and earlier than the Cretaceous or Carboniferous periods.
(c) Carboniferous Beds. — One of the most re- markable discoveries amongst the geological series of Palestine was that of Carboniferous rocks in the VS ady Nasb by H. Hauerman in 1868, J afterwards extended to the eastern bank of the Dead Sea at Leliruj, near es-Safieh, by the Expedition of the PEF in 1883-84.§ The formation consists of red, purplr;, and variegated sandstone, which the writer has named 'tlie Desert sandstone' below, sur- mounted by blue limestone containing shells and corals of Carboniferous limestone .species, such as Sjiiri/cr .itrintus, S. attcnuntus, Productus scabri- cuius, Orthis michelini, Sijringupora rnmulosn, Fertestella plehiti (?), and others. The occurrence af these strata in two widely-separated localities
• iltM rfrm Oritnt, p. 7.
♦ ' Phys. Oeol. Arabia Petnna,* Mrm, J'Kh\ t Qtuirt. Jmim. ileal. Soc. vol. xxv. p. 17.
I Mm. iirol. Arab. Petr. and Palut. p. 47.
p. 37.
suggests the idea that they once occupied an ex- tended and connected area, and have sub.sequently been dissevered by denudation. That the lime- stone is a marine (feposit fonned over the floor oi tlie sea during a period of submergence, is shown by tlie names of the fos.sils above quoted, which are all of marine species and genera. These fragmental tracts may only be relies of a formation which in- cluded tlie upper division of the Carboniferous system, but wliich has been subsequently removed by denuding agencies.
(d) Oretweoim B'.ds ; Nubian Sandstone (Russeg- ger). — In the absence of several formations wliich in Europe and the British Isles succeed the Car- boniferous, the Cretaceous strata are found in Arabia Petr.-ea resting on an eroded surface of the older formations above described, whether of Car- boniferous or of Archa'an age. The formation is, however, only found represented by its upper members ; the lower, belonging to the stages Neocomian, Urgonian, Aptian, and Albian not being here represented. Notwithstanding this hiatii.^, the Cretaceous is the most important of all the formations of Palestine, stretching from the southern margin of the Badiet et-Tth to the Lebanon, and forming large tracts of the great Arabian desert east of the Jordan-Arabah depres- sion. It is represented by two divisions ; the lower or Nubian sandstone (Cenomanian of D'Ur- bigny) the equivalent of our ' Upper Greensaml,' and by the Cretaceous limestone and marl, the equivalents of our Chalk and Chalkmarl (Senonian and Turonian). The Nubian sandstone consists of red and variegated, rather soft sandstone with a conglomerate of small pebbles of quartzite, granite, porphyry, and jasper at its base. Its thickness is exceedingly variable, owing to the irregularities of the floor of older rocks over which it was deposite<l, and its only fossils are fragments of plants at rare intervals. All along the escarpment of the Till from the Wady Hamr to the (iulf of 'Akab.ah it underlies the white limestones and marls of the upper Cretaceous beds, and along the fl.anks of the great western escarpment from 'A^abah to the northern end of the Dead Sea and bevond it is interposed between the crystalline rocks and the same calcareous strata.* On appro,aching the Sinaitic mountains, the Nubian and Desert sand- stones may be observed in isolated masses capping the Archiean rocks; sometimes rising from their bases in truncated pyramids ; and in the Wady el-'Ain, which is a continuation of the Wady Zelagah, one of the most remarkable old river courses in the peninsula, the walls of Nubian sandstone rise on either hand to a height of several hundred feet above the Hoor.t But it is in the Wady MftsaatPetra that this format ion is displayed to best advantage. Kising in nearly vertical walls from the door of the valley and its branches, the sandstone has formed the material out of which the tombs and temples have been sculptured in various forms of architecture, displaying marvellous varie- ties of colour in yellow, orange, red, and purple shades, which have called forth the admiration of all travellers (see Petra). These colours are due to the presence of various mineral pigments, of which oxides of iron, manganese, and jiossibly copper, are the most abundant.