PROCEEDINGS 
OF 
THE GEOLOGICAL SOCIETY OF LONDON. 
Tt pr mer RE 1842. | No. 91. 
June 29.—Seven communications were read. 
1. * Notices connected with the Geology of the Island of Rhodes.” 
By Mr..T. A.B. Spratt, Assistant-Surveyor of H,M.S.Beacon, Com- 
municated by C. Stokes, Esq., F.G.S. 
The observations detailed in this paper were made during the sum- 
mer of 1840. The geological structure of the Island of Rhodes, Mr. 
Spratt states, is simple, and the distribution of the deposits. easily 
defined. The formations consist of mica schist, shales, limestones, 
trachyte with basaltic rocks, Jarge beds of shingle, both anterior and 
posterior in origin to the volcanic era; and yery extensive tertiary 
deposits. ; 
The mica schists occur in the central districts near Alleyermah and 
Sclipio, but do not form ridges of very great altitude. 
The limestones are scattered in detached masses and rest appa- 
rently on argillaceous shales of a black, light cream or reddish colour, 
but the positive order of superposition the author had no opportunity 
of determining. He failed alse in detecting in them any organic re- 
mains, but he is of opinion that they are of contemporaneous origin 
with the strata near Smyrna, assigned by Mr. Strickland to the Hip- 
purite limestone. The shales are well developed in several places 
around the base of Mount Ottayaro, but more particularly in the 
valley west of the village of Embono. 
Both the schists and the limestones exhibit, Mr. Spratt states, 
proofs of great dislocations, and he is inclined to ascribe these effects 
to the outburst of the voleanic rocks which constitute so large a por- 
tion of the central and southern districts of the island. He mentions 
as instances of these disturbed beds a thin stratum of limestone which 
projects, near Lardose, from the enclosing schists like a wall, and tra- 
verses several valleys as well as ridges; also some curiously con- 
torted strata on the nor(th face of Mount Agramitty. 
The loftiest summits in the island are composed of limestone. 
Mount Attayaro (anc, /Atabyrius), the highest, exceeds 4000 feet in 
altitude, and at least thiree-fourths of it are composed of horizontal 
beds of limestone. The other principal calcareous mountains are 
Hlias, Agramitty, Archangilo and Lindo, all remarkable detached 
points, and believed by the author to have been islands during the 
deposition of the tertiary formations. 
Mr. Spratt likewise mentions in proof of the limestone mountains 
forming islands during the tertiary epoch, that at Mount Gallatah, 
near the north-east extremity of the island, fragments. of the rock are 
3R2 
