Corrrespondence — Colonel George Greenwood, 245 



that as the sea erodes the whole line of coast, the beach will travel 

 landward, and the peat and roots of trees which it covered will be 

 uncovered and submerged by the sea. But there needs no " subsi- 

 dence" for this. On the contrary, the raised beach which Mr. 

 Wynne mentions, and those near the English "■ submerged forests," 

 prove exactly the reverse. These raised beaches prove a rising of 

 the land. As I have said (page 123), the so-called " submerged 

 forests" are simply the results of the most gradual operations of 

 rain, rivers, and the sea. In former days the stream or the rain 

 valley cut its estuary far deeper even than low-water-mark, and 

 formed what is called an arm of the sea. In later days the sea 

 throws up a bank of shingle across the mouth of the deep-cut 

 estuary, completely dams itself out, and partially dams the streams 

 in, though these often soak through the shingle at low- water so as 

 never to rise near the height ' of high water. Thousands of such 

 cases exist in England. These sea beaches thrown up by storms 

 frequently stand not only very much higher than the high water of 

 the sea which throws them up, but the land behind them is often 

 much lower than the high water of the sea. And thus, according 

 to circumstances, peat, pasture, or wood, grows heloio the high-ivater 

 marh. The rapidity of the growth of alluvial deposit from ]3eriodi- 

 cal inland floods is then much increased. For all the alluvial wash 

 of the entire valley or water slope is here at once stopped short, 

 none of it can percolate the shingle into the sea. Deposit is rapidly 

 accumulated on deposit, and rooted trees are found under peat, in 

 peat, and above peat, not only on the shore outside the shingle bank, 

 but in cutting the sluices inside the shingle bank, and by degrees 

 the land which was below water-mark may be raised by alluvial 

 deposit far above high-water mark. When man appears on the 

 scene, if fine alluvium plasters up the shingle enough to hold back 

 the water, it is a common practice to dig a trench a few feet into 

 the clean shingle. The water may then be seen to flow into the 

 shingle in a stream. Or, if circumstances admit, a trench is cut 

 completely across the shingle bank, and occasionally cleaned. Then 

 come sluices and iron piping beneath the shingle bank. The land 

 drainage is let out at low water, and the sea Z^ep^ out at high water. 

 Millions of acres of our best pasturage far below high-water-mark 

 are held on this tenure. But when the streams are embanked, and 

 are let ofl' to the sea so perfectly as to prevent their natural annual 

 overflow, annual denudation of the old alluvium will take place 

 instead of deposit of new alluvium, and the land may again become 

 denuded far below the usual tidal level," The chalk flints men- 

 tioned by Mr. Wynne are quite en regie. That is (speaking literally) 

 all erratics, including what is absurdly called ''Northern drift" 

 have travelled on sea-shores. (See chapter on travelling of sea 

 beach in Eain and Rivers.) 



At page 2 of the same geological journal, Mr. Tylor, while he 

 considerately spares us "a gravel period," creates a bran new period 

 of his own — a pluvial period. With this implement (notwithstand- 

 ing that " the valley of the Somme had assumed its present form 



