Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/136

98 98 8. V. WOOD, JTJN., AND F. W. HARMER ON THE At Withersdale the uppormost layers consist of brown obscurely stratified marly brick-eartli, which is the character the deposit assumes in the Norfolk cliffs near Weybourne. These are overlain very unconformably by the Upper Glacial clay, which in some of the excavations is in its turn overlain by Plateau gravel. This marly brick-earth appears, from other and not far distant excava- tions at lower levels, to pass down into alternations of laminated brick-earth and loamy sand, interstratified in which there occur in one of the excavations beds of rolled pebbles. On the north side of the Waveney at Starston the Contorted Drift presents the character which it possesses at Elsing and Lyng (see section VII.), of a gritty earth enclosing small flints and minute fragments of chalk, Nume- rous as are the excavations in the Contorted Drift around Harleston, they do not afford the means of showing in a satisfactory way the interglacial excavation of the main valley of the Waveney, but only of the small tributary valley at Starston. They, however, show abundantly the considerable thickness in which this drift originally extended across the region now occupied by that valley, along the line of section XVII. Fig. 17. — Section XVII., across the Waveney Valley near Harleston. (Length 4| miles. Vertical scale 17| times the horizontal.) N.W. Tributary valley. Large pit (see fig. 18). East End of Harleston. Excavations 6 furl. N.W. by W. of Withersdale church, River the lower one in a large Waveney. sand-gall in No. 6. 1. The probable position of the Chalk. 6. The Contorted Drift, which may perhaps be underlain by the Lower Grlacial sands, and even by the Chillesford (Crag) beds. 7. Middle Grlacial. 8. Upper Glacial. 10. Postglacial valley-gravel and recent alluvium. N.B. The central portion of this line of section is conjectural for want of open sections such as occur at either extremity. It is not unlikely also that the interglacial main valley is con- cealed beneath the alluvium which covers the bottom of the ex- ceptionally wide elbow in the valley at this point. The importance of the Starston excavation consists in its having afforded, when we examined it in 1871, the only indication besides the bed a of the Yare valley which we have been able to discover of a land surface having existed during the interval represented by the unconformity and denudation that we have been describing. In this excavation (section XVIII.) there occurs upon the denuded surface of the Contorted Drift, and between it and the overlying '