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Show EOCENE PERIOD. [Ch.XXII. been invariably brought back again to the opinion, that the chalk was originally continuous, on a more deliberate review of the whole phenomena. . It may be useful to considet· the only other alternative of the hypothesis before explained. If the marine groups, Nos. 1, 2, 3, were not originally continuous, it is necessary to imagine No. 77. 1, Chalk o.ntl Upper green-sand.} 2, Gault. Marine. 3, Lower green-sand. 4, Weald clny. } Fresh-wnter 5, Hastings sands. ' that they each terminated at some point between thci1· present outgoings and the secondary strata of the Forest ridge. Thus we might suppose them to have thinned out one after the other, as in the above diagram, and nevet· to have covered the entire area occupied by the fresh-water strata, Nos. 4 and 5. We grant that had such been the original disposition of the different groups, they might, as they gradually emerged from the sea, have become denuded in the manner explained in the last chapter, so that the country might equally have assumed its present configuration. But, although we know of no invincible objection to such an hypothesis, there are ce1tainly no appearances which favour it. If the strata Nos. 4 and 5 had been unconformable to the Lower green-sand No.3, then, indeed, we might have imagined that the older groups had been disturbed by a series of movements antecedently to the deposition of No.3, and, in that case, some parts of them might be supposed to have emerged or formed shoals in the ancient sea, interrupting the continuity of the newer marine deposits. But the group No. 4 is conformable to No.3, and the only change which has been observed to take place at the junction, is an occasional intermixture of the Weald clay with the superior marine sand, such as might have been caused by a slight superficial movement in the waters when the sea first overflowed the fresh· water strata. Ch. XXII.] VALLEY OF KINGSCLERE. 305 On the other hand, the green-sand and chal proach the central axis of tl le W ea ld are not k, as they ap- ~ d littoral shells, or any wreck f h f~ oun to contain . • • 0 t e tesh-water t t 1 might mdiCate the existence of . . s .ra a, sue 1 as wasting cliffs H d . an Island with Its shores or · a any such sign b d' have been inclined to suppose tl s een Iscovered, we might 1e geoo'raphy f th . have once borne some resembl h o e regwn to gram No. 77. ance to t at exhibited in the dia- Dr. Buclcland on Palleys of Ele ( . to Dr. Buckland for an able memoi ~a. w~.-We. are mdebted districts of similar form and t r m Illustration of several s ructure to the We ld 1 . occur at no great distance in the south f E 1 d a : w 1Ich . . . ] d ' o ng an . His pa IS In tit e ' On the formation of the ValJe f . per other valleys by the elevation of th y o Km~sclere and them*.' e strata whiCh enclose The valley of Kingsclere' situate a fe w m1' I es south of New~ Valley of lClngsclere. 0 J b, Anticlinal line marking the 0 .t d' ppost e tp of the strata on each side of it. No.79. Stction ac,·oss tlle Valley of K' l , .... , angsc ere from north to south. 1' Chalk with flints 3 U • 2, Lower chalk without flints ' pper green-sand, or fh-estone, containing beds of chert. . VoL, III. * Gcol. Trans.) 2nd Sel'ies, vol. ii. p. 119. X |