GEOLOGY 



and silts are mostly marine or estuarine, and as Mr. Skertchly has 

 pointed out, there is every gradation from the ' buttery clay ' (as it is 

 called) to silt. The clays contain woody fragments with vivianite 

 (phosphate of iron), and there is usually at the base a floor of sand and 

 gravel with marine shells. The fossils contained in these deposits are 

 the familiar estuarine forms, such as Scrobicularia plana [piperata), Tellina 

 balthica, Cardium edule, Ostrea edulis and Mytilus edulis, many of them 

 dwarfed. In addition we occasionally find bones of animals such as are 

 found in the alluvium, and also remains of whale, grampus and seal. 



The peat contains trunks of trees, remains of ' buried forests,' which 

 are usually found near the borders of the Fenland or around islands in 

 the levels. 



The Fenland area was once an arm of the sea, the materials were 

 mostly brought in by the sea, and the silting up has long been going on. 



Formerly a morass, with here and there extensive pools of water, 

 the Fenland has been greatly modified by the works of man. Portions 

 of it were embanked and drained by the Romans ; but after their 

 departure the sea returned, and large tracts were covered with beds of 

 marine silt. These areas have again been reclaimed and converted into 

 productive lands. In some places a breadth of three miles has been 

 gained since the Roman occupation. 



The scenery is naturally monotonous, but it has its own peculiar 

 charms, although, with the exception of the willows and aspens which 

 fringe the watercourses, there are few trees. 



The Lynn Deeps, in which are channels over five fathoms deep in 

 the middle of the Wash, may have been scooped out of the clayey 

 deposits by tidal action ; but in Mr. Jukes-Browne's opinion the scour of 

 the tides may have operated on an ancient valley formed by the old Fen 

 rivers. This subject may be studied with reference to the deep alluvial 

 valleys in East Norfolk, previously mentioned. In these old times the 

 Fen rivers may have joined the Rhine estuary, and the marshlands in 

 north Norfolk may be remnants of the old alluvial valley in Pleistocene 

 times. 



On the foreshore north-west of Old Hunstanton and Holm, and 

 at low-water level between Hunstanton and Brancaster, there are traces 

 of a ' submerged forest,' equivalent probably to one of the peaty layers and 

 buried forests in the Fenland. Oak, elm, birch and yew, willow and 

 sallow have been found in this peaty deposit, the roots being fixed in the 

 bed underlying the peat. 



Some of the alluvial tracts near Wells, Stiffkey and Morston, are 

 known as salt marshes, as they are liable to be flooded at high tide, which 

 is not the case at Brancaster, Burnham and Cley, where the marshes are 

 protected by embankments. 



BLOWN SAND 

 The marshes on the north coast of Norfolk, as well as those 

 bordering the Hundred stream and the Bure, near Breydon Water, are 



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