314 Geological Society. 



a breccia, composed of fragments of white limestone in a pale red 

 paste, or of red limestone in a white paste. At the eastern extre- 

 mity of the Gulf, a thinly bedded limestone alternates with bands of 

 pale red jasper, the strata dipping 50° north-west ; but in some 

 places they are curiously contorted. The jasper increases in quantity 

 towards the north-west, the limestone becoming less prominent. 

 Mr. Hamilton did not land on the north side of the Gulf, but several 

 points appeared to him, viewed from the sea, to consist of a brown 

 arenaceous conglomerate. 



8. Rhodes. — The northern half of the island, the portion visited 

 by the author, consists chiefly of tertiary marine deposits, of se- 

 condary limestone and of scaglia, with sandstones and conglome- 

 rates. No igneous rocks were observed in situ, but numerous 

 pebbles of greenstone and other traps were noticed in the conglo- 

 merates near the centre of the island. 



Tertiary Strata. — These consist of a shelly testaceous lime- 

 atone, sandstone, and conglomerates, and extend in a zone of varia- 

 ble breadth, having a quaquaversal dip, along those parts of the 

 island visited by the author. At the north-east end, the tertiary strata 

 rise into high and considerable hills, which sti'etch across the island 

 from east to west. 



The following is the order of succession : — 



1. Summit of the hills three miles, south-south-west of the town 

 of Rhodes. 



Sandy gravel and conglomerate consisting of Feet. 



pebbles of scaglia 10 to 13 



Fine sand, with indications of false stratifica- 

 tions, true dip 5° north-east 10 to 15 



Gravel 8 



Sand, with perpendicular veins of marl 10 to 12 



Sand, with concretions of marl 



Sand, with bands of marl 



2. These beds repose on an extensive formation (considered to 

 be from 200 to 300 feet thick) of yelloAV, calcareous, shelly conglo- 

 merate, the beds of which dip 10° to north-east. It contains nume- 

 rous shells of the genera Pecten, Cardium and Venus, and it is the 

 stone principally used in masonry. It extends to the town of Rhodes, 

 and re-appears to the south of the table-land in nearly horizontal 

 beds, some of which are very arenaceous. It is extensively de- 

 veloped in several places along the coast, as far as Lindo, where 

 it rests unconformably against the secondary limestone. 



3. A bed of sandy marl, containing thin bands of calcareous marl. 

 Thickness not great. 



4. A thick bed of conglomerate and gravel, extending a consider- 

 able distance to the south and south-west, and rising into lofty hills, 

 which form steep and broken cliffs on the western coast of the 

 island, several miles from Rhodes. It thins out gradually further 

 south, resting at the entrance of a deep valley, upon upraised beds 

 of blue and white scaglia and sand. 



