GEOGRAPHY AND CLIMATE
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numerous rugged and irregular islands with deeply dissected peninsulas. A general picture of the area is that of an upland terrain which has been invaded by the sea.
The uplands and mountains are eroded remnants of rock formations, in which relative resistance of rock and structure through differential erosion are clearly recorded. As the region lies within the northern limits of the tropics, frosts even on Tai Mo Shan are of the rarest occurrence, and hence weathering depends almost completely upon the chemical action of the atmosphere aided by the alternation of wet and dry seasons. Erosion is likewise due to water action which is at a maximum during the torrential rains of the summer monsoon. Again denudation is aided by the excessive wind velocities of the typhoons and to a much lesser extent by the gentler breezes of the dry winter monsoon from Central China. Because of the destruction of forest growth and vegetation wrought by the agricultural population by sickle and grass fires, the soil and rock mantle are left unprotected except by their own cohesion. Intensive efforts have been made to limit and control these nuisances by rigid regulations and systematic reafforestation. In consequence of this, bare rock surfaces and loose boulders occur commonly on the higher surfaces and steeper slopes.
The laterite-type product of decay is locally such, however, as to provide an impervious mantle for the underlying rock. In colour and composition the products of weathering ac- curately reflect their rock origin. Although frost action is absent, mechanical disintegration due to hydration, carbona- tion and temperature changes, has resulted in the formations of gravel and boulders over the surfaces of some rock types. The net result of the erosion cycle is that of an upland system with rocky mountain peaks and well-defined ridges giving an impression of partly matured topography. In some areas the topography shows that adjustment to rock structure and resistance to weathering and erosion are very complete. This is evidenced particularly in the general anticlinal