Geological Society. 315 



Near Archangelo, half-way between the town of Rhodes and 

 Lindo, a similar system of tertiary rocks is extensively developed. 



About one mile north of Lindo Mr. Hamilton noticed between 

 the tertiary and secondary series a thick bed of large limestone peb- 

 bles, with sometimes quartz pebbles and boulders, cemented by a 

 hard calcareous paste. This conglomerate rests immediately on 

 the blue limestone, filling up its interstices ; and it is considered by 

 Mr. Hamilton to be the lowest tertiary dejiosit. 



Secondary Rocks. — The greater part of Rhodes consists of sca- 

 glia, generally considered to be the equivalent of the cretaceous sy- 

 stem of Europe. It is composed, (1.) of red and brown sandstones 

 with conglomerates ; (2.) of whitish gray and red scaglia limestone ; 

 and (3.) of blue limestone; but the last deposit Mr. Hamilton 

 considers to belong to a different epoch. 



1. The sandstones and conglomerates occur near the centre of 

 the island, and apparently form the upper division of the deposit. 

 A red conglomerate, which is found between Apollona and Embona, 

 dips 50° to the south-south-west, and rests conformably upon whitish- 

 gray scaglia. At the same locality exist indurated red marls and 

 sandstone grits ; and at the north-north-west foot of Mount Atairo 

 is another bed of conglomerate, containing chiefly boulders of green- 

 stone, and a greenish granular rock, but inclosing also rounded 

 masses and pebbles of the gray scaglia of the neighbouring hills. 

 The greenstone was not seen by Mr. Hamilton in situ. 



2. The scaglia limestone is chiefly developed in the lofty ridge of 

 Mount Atairo (anc. Mons Atabyrius), which is from 3500 to 4000 

 feet in height. The summit is a narrow ridge about two miles 

 long, extending from north-east to south-west, or nearly in the di- 

 rection of the axis of the island. The bed dips from 15° to 20° to 

 the south-east. The upper portion consists of thick-bedded gray 

 scaglia, without flints ; lower down occurs a thinly-laminated lime- 

 stone, with tabular masses or beds of flint ; and still lower, the beds 

 are again thicker and the flints are nodular. The total vertical di- 

 mensions of these deposits is from 800 to 900 feet. Beneath them, 

 the scaglia is interstratified with a red marly limestone, and further 

 down the hill are thick beds of scaglia without flints. Below the 

 village of Embona, situated to the north-west of the mountain, a 

 greenish compact sandstone crops out from beneath the limestone 

 of Mount Atairo, and dips to the south-east. The range of hills 

 to the north-north-east consists also chiefly of the gray limestone, 

 which rests on the red and brown sandstones. Mr. Hamilton did 

 not ascertain how far the formation ranges to the north-west. 



The Acropolis of Camiro, on the east coast of the island, and six 

 miles north of Lindo, stands upon an insulated table- rock of whitish 

 compact scaglia, encircled at its base with tertiary strata. 



3. The blue limestone is classed provisionally by Mr. Hamilton 

 with the secondary rocks ; but he is of opinion it may be of the same 

 age as the limestone of Halicarnassus, and belong to a much older 

 system. It occurs extensively along the east coast, particularly near 

 Lindo, where it forms high and steep hills, against which remnants 



