Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/572

 Section across the Yare Valley at Trouse.

The chalk 1 forms the fundamental stratum. 2 is the Chillesford sand and clay. 3 is the pebbly sand and pebble-beds which succeed to that clay, and which expand northwards into the Weybourne sand and Boulder Till of the Cromer-Cliff section; this bed is uncomformable to the Crag and Chillesford beds, is palaeontologically distinct from them, and is characterized by the first appearance in England of Tellina Bathica. 4 is the "contorted drift," here uncontorted, and about 15 feet thick, being only a sixth or seventh part of the thickness which it attains in the north of Norfolk and in the Cromer Cliff. 5 is the Middle Glacial sand. 6 is the Boulder-clay, or Upper Glacial. And 7 is a Postglacial valley-gravel that has a much greater development a short distance further down the valley. The alluvium is included in 7.