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EXPOSURES ALONG ESTRADA CENTRAL OF PERNAMBUCO 81 



Between Bezerros and Goncalves Ferreira the railway appears to cross 

 and recross the contact between coarse grained granites and schists. 

 The dip of the schists changes, but it is always high, sometimes appar- 

 ently oh end, with an east-west strike. One of the cuts, 6 meters deep, 

 exposes schists beautifully for several hundred meters. 



At Goncalves Ferreira station (kilometer 127; elevation, 509 meters) 

 the rocks continue to strike east-west. The mountains about 2 kilo- 

 meters north of the railway station expose enormous and beautifully 

 exfoliated boulders and bosses of massive granite with black inclusions. 

 One of these large blocks is beautifully fluted. From the railway station 

 this mountain, known as the Serra de Imburana, is an impressive sight. 



Where the railway goes round the west end of the mountain, there is 

 exposed near the track a layer of coarse water worn pebbles varying in 

 size from 5 to 20 centimeters in diameter. 



These pebbles appear to be one of many *~^\TmT)iir'ct7ici 

 separate patches rather than part of a sheet, -/ « / 

 though there may be such a sheet over the - v t / , x 



Caruarti plain. About 2 kilometers west of v ^^^J^t^^^lL^ 

 Goncalves Ferreira, at the foot of the Serra 

 Imburana, there is a fine exposure of a very fsj 

 dark gneiss with large pink feldspars. figuke is.— Apparent Relation of 



Three kilometers east ofCaruaru the rail- i chists and Granites East °f 



Caricaru. 



way passes from schists to granites ; the 



schists appear to dip north at an angle of 80 degrees, as if passing 

 beneath the granite mountain, Serra Imburana. Immediately east of 

 Caruarti the granites contain aplite dikes. 



Caruarti station (kilometer 139 ; elevation, 537.7 meters) stands on a 

 flat plain near the base of a conical granite hill. In sight of the town 

 both north and south are ranges of mountains approximately parallel with 

 the Ipojtica valley and with the general direction of the railway. The 

 granite peak at Caruarti exposes in places exfoliated blocks and bosses, 

 but in July, 1899, the greater part of it was covered with vegetation. 

 The rocks at the base of the peak are coarse grained granites, and these 

 cover the country for miles around. The plain west of Caruarti is cov- 

 ered with a thin coating of waterworn quartz pebbles. There are no 

 heavy forests hereabout ; the vegetation is low and scrubb} r , probably 

 owing to the droughts to which this region is sometimes subjected. 



West of Caruarti there are many good exposures along the railway of 

 coarse grained and beautiful pink granites, popularly known as " Scotch 

 granite." These granites are cut here and there by big quartz veins and 

 aplite dikes ; in places the rocks are gneissic, occasionally they are 

 decomposed. 



XII— Bull. Geol. Soc. Am., Vol. 13, 1901 



