woodworth: geological expedition to brazil and chile. 115 



south Brazil are more or less patent to every visitor. The dissection 

 of the coastal slope and the depression of the resulting Serra do Mar 

 has given rise to commodious harbors so uniformly wanting because 

 of the unlike geological structure and form on the west coast of South 

 America. But the Serra do Mar renders ingress to the country 

 exceedingly difficult and possible for roads and railways only along 

 certain routes. Back of the Serra do ^lar for the most part the lands 

 slope toward the interior of the continent, and the large rivers, naviga- 

 ble by small boats, serve only with ease to carry commerce into the 

 interior. The transportation to the coastal border of the plateau is 

 everywhere upgrade making the export of the products of plantations 

 and the forest more costly than the importation of foreign goods, 

 an item of cost which is offset on the inward journey by the necessity 

 of ascending the Serra do Mar, and, to reach the trap plateaus, of 

 surmounting the Triassic escarpment. Transportation is naturally 

 slow to develop, except where peculiar conditions, such as give rise 

 to the rich coffee-fields of Sao Paulo, have repaid the construction of 

 railways. 



The recently uplifted plains of alluvium bordering the harbors afford 

 the sites for the first settlement of the sea-coast. The variable relief 

 of the dissected front of the Serra do Mar furnishes stations for resi- 

 dence at altitudes great enough for Europeans, whose affairs require 

 their daily presence in the federal capital, to escape the languishing 

 effects of a continuous abode in the hot zone at sea-level, but the way 

 to these retreats calls for special and costly methods of transportation, 

 as in the case of the route to Petropolis. Owing to the mountainous 

 relief of the coastal slope of the Serra do Mar and the luxurious growth 

 of tropical vegetation the inhabitants enjoy outlooks unsurpassed in 

 any land. As a scenic route for the traveller the railway journey 

 from Paranagua to the summit of the Serra through the defile of the 

 Ypiranga is surprisingly pleasant, and at many points exciting. 



The contrast between this region and the surface of the plateau is 

 striking. The tableland is the seat of production. Variations in the 

 geological character of the surface modified by altitude and rainfall 

 come sharply into play. In northern Sao Paulo and adjoining parts 

 of Minas Geraes the soils known as terra roxa and terra rermehia 

 developed by decomposition of the trap sheets which invade the 

 Permian terrane afford under the peculiar conditions of rainfall there 

 existing the richest coft'ee-fields in the world. Farther south the 

 Devonian and Carboniferous sandstones present less favorable 

 conditions. Open campos or prairies characterize much of the region 

 underlain bv Palaeozoic strata. 



