T. SPRATT ON THE COAL-BEARING DEPOSITS NEAR EREKLI. 531 



On the Geology of Erekli. 



The Acropolis and part of the town walls of Heraclea stood upon 

 the crest and slopes of a bold and almost isolated hill rising from 

 the east side of the bay, formed by the promontory of land to the 

 north-west of it, now called Cape Baba, but anciently the Acheru- 

 sian Peninsula by Xenophon ; for this city was the place from 

 which he embarked for Greece, with his army, after his celebrated 

 retreat. 



The summit of this hill (Acropolis) consists of a capping of reddish 

 indurated shale, a few feet only in thickness, and overlying stratified 

 beds of tuffs, greenstone, volcanic mud, and trachyte conglome- 

 rates, by the outburst of which the reddish shales were evidently 

 uplifted and altered in their colour and character ; but Mr. Poole 

 calls it sandstone, no doubt from a too hasty examination. 



A portion of the same altered shales, or rather marls, appears also 

 at the base of the Acropolis, near the shore, on its west side — like- 

 wise to the north and eastward of it, with the lavas intermediate. 



A valley to the south of the Acropolis, in which is a large part of 

 the modern town of Erekli, separates it from another hill over the 

 coast, which is composed of whitish and grey marls, belonging, no 

 doubt, to the same group as the indurated stratum capping the 

 Acropolis, and the altered marls existing at its base. 



These white and grey marls dip to the south-west at an angle of 

 30°, except on the east side of the hill, near the large burying- 

 ground at its base, where they are nearly vertical, and where they 

 are much discoloured and decomposed through contact with the 

 trachyte conglomerates and stratified lavas which have burst out 

 beneath them. 



The age of these marls I was not able to ascertain, as the only 

 fossil obtained from them was an oyster, too friable, however, to be 

 preserved, but sufficient to show that they were of marine origin. 

 From the form of the oyster I was disposed to consider the deposit 

 to be of Miocene, or perhaps an earlier age. 



In the promontory to the north and north-west of Erekli the 

 volcanic productions of tuffs, trachytes, and basaltic conglomerates 

 prevailed, having in some parts both uplifted and also overflowed 

 the marine marls. 



It is perhaps worth noticing, in concluding these remarks upon 

 the volcanic character of the locality, that the ancients must evi- 

 dently have recognized the plutonic or igneous origin* of these lava- 

 beds, notwithstanding their general stratified condition ; for Xeno- 

 phon states that a cavern was shown in the Acherusian Peninsula 

 that led to the gates of Hades, and from which Hercules drew forth 

 Cerberus, the guardian of its portals. 



Strabo says it lay to the north of the town, and was two stadia 

 deep ; but I could hear of no such cavern in the neighbourhood. 

 Yet it is possible that some traces of an extinct crater or volcanic 

 vent mav exist here, where, as I have shown, lavas and beds of 



