DRIFTS OF FLAMBOROCron HEAD. 385 



must be traced, the coast-line here passing from the low ground of 

 Holdorness (an unsubmorgod corner of (ho ])lain of tlie Nortli Sea) 

 to the elevated and broken region of the Wolds and Moorlands, and 

 of the North of England generally. And that the nature of this 

 connexion is by no means obvious has been shown in the former 

 attempts to unravel it. The promontory affords almost unparalleled 

 facilities for such an investigation, for with an area of less than 

 sixteen square miles it possesses a precipitous coast-line over fifteen 

 miles in length, presenting magnificent sections in various directions 

 through the thickest part of the drifts ; and has, besides, in the 

 interior, three or four miles of railway-cuttings, and chalk pits in 

 abundance. If the glacial history of an area thus laid open cannot 

 be deciphered, there must indeed be slight hope for less favoured 

 localities. 



In classifying the Yorkshire Drifts twenty-four years ago, Messrs. 

 Wood and Home * recognized in the Boulder-clays of Holderness 

 three divisions : the " Hessle Clay," the " Purple Clay," and the 

 " Basement Clay " ; and of these divisions they supposed that the 

 first-named and the last died out before reaching the rising ground 

 of the Chalk Wolds and Flamborough, and that the " Purple Clay" 

 alone (with its associated gravels) extended over the headland and 

 the country lying to the northward of it. 



In a later paper, by Mr. S. V. Wood t, this supposed absence of 

 the Basement Clay from the coast sections north of Holderness was 

 stmngly insisted upon ; and this interpretation remained for many 

 years prevalent, and was incorporated in most discussions of the 

 Yorkshire Drifts iji. 



It was with a learner's faith in this view, and with a similar 

 faith in the recurrence of " interglacial " periods, that I commenced 

 the study of the Flamborough sections over twelve years ago. But 

 with the gradual accumulation of opposing evidence my confidence 

 was weakened, until at length I have been driven to contrary con-, 

 elusions on both points §. 



In the following pages are embodied the results of my investiga- 

 tion. After, a short description of the physical features of the area, 

 and of the general distribution of the drift, a detailed account of 

 the sections will be given ; the various deposits will be afterwards 

 separately discussed ; and in conclusion certain questions as to the 

 origin and coirelation of the beds will be touched upon. 



The labours of previous observers will be referi-ed to as the 

 sections noted by them are described. 



* ' On the Glacial and post-Glacial Structure of Lincolnshire and South-east 

 Yorkshire,' Quart. JoJirn. Gaol. See. vol. xxiv. (18()8) p. lACy 



t 'On the Eelation of the Boulder-clay without Chalk, of the North of 

 England, to the Great Chalky Boulder-clny of the Soutli,' Quart. Journ. Geol. 

 Soc-. vol. xwi. (1870) p. 90. 



I K. g. Jas. Geikie's ' Great Ice Age,' 2nd ed. pp. oGfi et scqq. 



§ In Mr. S. V. Wood's latest paper ' The Newer Pliocene Period in England,' 

 Quart. Journ. Geol. Soc. vol. xxxviii. (1882) p. 685, he seemed himself to 

 assign a more extended range to the IBasemeut Clay, and to recognize this 

 division ou the coast north of Flamborough. 



