180 



MEXICO, CENTRAL AMEErCA, WEST INDIES. 



So extensive is the area of the Mexican mineral region that it may be estimated 

 at four-fifths of the whole territory. The chief metalliferous zone is that of the 

 western Sierra Madre from the Arizona frontier to the isthmus of Tehuantepec ; 

 but the other Sierra Madre is also very rich, especially in the States of San Luis 

 Potosi and Hidalgo. Besides gold and silver the Mexican highlands contain 

 deposits of platinum,, copper, lead, iron, manganese, and quicksilver, the last of 



Fio-. 77.— Yield of Gold and Silver in VAiiiotrs Cottnteles since 1492. 



NEW WOELD. 



Mexico: £848,000,000. 





Bolivia and Peru : £820,000,000. 



Uaited States : £400,0u0,0i;0- Eest of America : £500,000,000. 



OLD WORLD. 



Australia: £300 000,000. 



Each square represents £400,000. 



great value in the reduction of the ores. Coal has been found in Sonora, on the 

 banks of the Rio Grande, in the Sierra de Tamaulipas and in the southern 

 uplands. Sulphur is obtained in the craters both of the active and quiescent 

 volcanoes ; near Tuxpan are found petroleum springs ; by scratching the surface 

 the sulphates and carbonates of soda, saltpetre, sea salt are turned up ; lastly, there 

 occur quarries of marble, onyx, jasper, basalt, obsidian, while certain rocks abound 

 in precious stones. 



