132 CORRYS WITH OR WITHOUT LAKE-BASINS. 



locked bays or among islands, as in such places 

 there must be cross currents working in irregularly. 

 The undermining of a cliff cut by two or more oblique 

 master-joints or faults may also form a coose, as a 

 large mass may thereby lose its support and slip out 

 to sea, to be afterwards broken up and dispersed by the 

 waves. Such cooses, in different stages of formation, 

 may be observed on various coast-lines ; but all the 

 cooms among the hills that may have been formed 

 from the slipping of a mass of rock are not due to 

 sea action, as springs, or even the wind, may erode 

 and carry away some weak beds or strata, and thereby 

 leave unsupported a mass bounded by master-joints 

 or faults. In such cases, however, the debris of the 

 mass will be scattered on lower ground, or occur in 

 the form of a bar or mound, unless carried away by 

 ice or a river. 



Blanford has pointed out that, in tropical climates, 

 while marine actjon is at a minimum, meteoric abra- 

 sion is at a maximum ; l the quantity of detritus pro- 

 duced by the heat, and carried down by rivers into the 

 sea, forming large alluvial flats, which protect the 

 coast-lines from marine denudation ; or in places 

 where such deposits cannot form, coral reefs grow, 

 fringing the coast, and having a similar effect. 



Explorers of arctic regions have taught us that, 

 in those latitudes, most of the detritus due to atmos- 



1 "Geology, Abyssinia," p. 151. 



