Coast Line Formation of the Western District. 31 



Inland of this second ridge, at a distance of about a mile, 

 the land rises in steep hills, and, in some places, limestone 

 bluffs, which extend from Tower Hill westward for from six 

 to seven miles. The bluffs are chiefly of an indurated 

 limestone, but the sloping hills have a thick bed of soft 

 limestone, with alDundance of shell spicula and other marine 

 remains ; and the whole has evidently Ijeen the sea-coast of 

 what has in all probability been an indented bay, formed 

 between the Tower Hill and the outflow -of lava before 

 described as coming from Mount Rouse. 



The inclosed basin between the second line of ridge and 

 the bluff is occupied by a bed of stiff black diluvium, 

 through which flow the surplus waters of Tower Hill and 

 the country to the north-east and the River Moyne, which 

 latter rises in the marshes and stony rises south and west of 

 JVTount Rouse. 



Until recently this flat was more or less a marsh during 

 the greater portion of the year, but it has now been re- 

 claimed by drainage. 



On a portion of these flats west of the River Moyne, well 

 shafts have been sunk to depths varying from 14 feet to 

 18 feet deep, and an original sea bed disclosed, with abun- 

 dance of recent shells. From the River Moyne westward 

 the land is chiefly undulating bluestone ridges, until the 

 sea-coast or the limestone beds before described are reached. 



The formation of the land and its three distinct coast lines 

 as described indicate considerable changes of coast, and 

 these changes must have occurred since the upheaval of 

 the land to its present level ; and so far from the line of 

 coast being even now fixed, I have often thought when 

 standing on the present sand dunes that I could detect in 

 the paler colour of the sea a short distance from the 

 present coast a new formation of coast line in progress, but 

 the data on which I have arrived at this conclusion is not 

 sufficiently positive to give reliable evidence of the fact ; 

 but, assuming such to be the case, the progress of formation 

 must of necessity be slow owing to the long period requisite 

 to accumulate fragments of shell sufficient to form these 

 extensive mounds. The materials brought down by the 

 river in floods can have little effect in hastening such forma- 

 tion, because although the outflowing current is strong- 

 enough to carry along the finer particles of mud sufficient to 

 discolour the water, it has not velocity sufficient to convey 



