File:The Quarterly journal of the Geological Society of London (1904) (14598402009).jpg

Identifier: quarterlyjourna601904geol (find matches)
Title: The Quarterly journal of the Geological Society of London
Year: 1845 (1840s)
Authors: Geological Society of London
Subjects: Geology
Publisher: London (etc.)
Contributing Library: Smithsonian Institution Libraries
Digitizing Sponsor: Biodiversity Heritage Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
herside, with a continuous east-north-easterly strike, of the Tertiarysedimentaries, up to and including the Sarmatic. The dam thus formed, confining the Marmora water from anyoutlet to the westward, was the proximate cause of the cutting ofthe Bosphorus, and of the drainage of the Marmora into the BlackSea, during Pliocene times. Later on, as will be shown, it similarlyresulted in the cutting of the Dardanelles and the drainage of thecombined Black-Sea and Marmora water into the Mediterranean. Since no traces of Tertiary deposits have been found as yet alono-the Bosphorus, to my knowledge, it is useless to speculate as tohow or when the valley, which now forms the channel, first took aconnected shape in the old rocks. To all appearance it was developedon the recession of the Sarmatic sea, as that of a river running to the north-eastward, and confined within a narrow rocky gor°-e niung n J t-i Vd M*a*H p.iop^nXng BidB.iaiij^soj^iag tna^uia^ bo v(\v\uv\\y( ina^wiiQ sjapireai 3snoim(3iq
Text Appearing After Image:
Vol. 60.) EOCENE, ETC. SURROUNDING THE DARDANELLES. 263 between Boumili Hissar and Kandili, where the general water-parting between the present drainage to the Black Sea and that to the Sea of Marmora crosses the channel (23). At Beikos Ostreaedvlis, of which a specimen is now in the British Museum (NaturalHistory), has been found in grey clay, about SO feet below thepresent water-level, and therefore the Devonian rock-bottom of thelateral valley, which joins the Bosphorus at this place, must belower still. The Buyuk-Dere valley is also partly filled up withbrick-earth; and if these and other lateral valleys were cleared oftheir post-Tertiary accumulations, the Bosphorus channel wouldtake the shape of an ordinary river-valley, with numerous smallaffluents. The slope of the longitudinal section along the deepest part ofthe channel, with the exception of a remarkable hole of (iQ fathomsabreast of Kandili, to which I shall refer later, is fairly uniform,the depths increasing from 20 fatho

Note About Images