The Quarterly journal of the Geological Society of London . rth to Peterborough. Such an area offers many conditions favourable for a considerationof the subject of this paper, being bounded by Cretaceous rocks eastand south, and the outcrop of the Oolites flanking the west, whilethe sea opens to much of the north; and the included country, beingnearly flat, presents a minimum of complications. This tract slopes gradually to the sea, which it resembles in itsdreary uniformity. Every village and town, however, indicates apatch of higher land than that around it; and from Chatteris, roundby Hadd
The Quarterly journal of the Geological Society of London . rth to Peterborough. Such an area offers many conditions favourable for a considerationof the subject of this paper, being bounded by Cretaceous rocks eastand south, and the outcrop of the Oolites flanking the west, whilethe sea opens to much of the north; and the included country, beingnearly flat, presents a minimum of complications. This tract slopes gradually to the sea, which it resembles in itsdreary uniformity. Every village and town, however, indicates apatch of higher land than that around it; and from Chatteris, roundby Haddenham and Ely, to Littleport the level is relatively by nomeans low. South of this, too, by Denny Abbey, Cottenham, Ramp-ton, Over, and St. Ives, towards Huntingdon, there is a line of higherground. And south of this, to the east of Cambridge, are low Chalk-hills, and to the west of Cambridge an undulating country of Cre-taceous outliers and hills of Boulder-clay and Oxford Clay. All thehigher land north-east of Cambridge is capped with Shanklin Sand (?).. 1866.] SEELET DRIFT OP THE FENLAND. 471 And the great level itself is the Fen-clay, in which are a few isolatedreefs of Coral-rag, and some stone-bands in its Oxford-Clay member,which clay covers nearly the entire area. There are in this region three kinds of drift—namely, a Boulder-clay covering the high land, a coarse gravel which caps the hiUs,and the fine gravel of the plains. The Boulder-clay is widely spread to the west of Cambridge. Itrarely, if ever, forms hills, though frequently capping them. Yetit is thick; for, near Caxton and Longstow, wells in it have beensunk 160 to 180 feet: and the clay seems sometimes to fill upvalleys ; for a well in the village of Caxton, half a mile north of thedeep sinkings, found the drift reduced to a thickness of 14 feet. From. March to Longstowe it is generally a dark-blue depositwholly unstratified, and more or less abundantly charged with frag-ments of Chalk and Septaria and Lime
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectgeology, bookyear1845
