BRANNER-AGASSIZ EXPEDITION TO BRAZIL 



199 



north of Cachoeira station the road cuts decayed crystalline 

 rocks (granite), and winds up a granite hill past the Cachoeira 

 waterfalls of Rio - Mundahu to Albuquerque station. These 

 falls are over granite rocks. From Albuquerque west along the 

 Assemblea branch of the railway the line is 

 upon granites or closely related crystalline 

 rocks all the way to Assemblea. At Albu- 

 querque the western branch line leaves Rio 

 Mundahu and crosses the watershed into the 

 drainage of Rio Satuba, then passes over a 

 hiijh divide and descends into the basin of the 

 Rio Parah3^ba. Between Albuquerque and 

 Bittencourt there are several cuts in decayed 

 granite and in places large exfoliated granite 

 blocks. 



Bittencourt station is on a flat-looking granite 

 plateau at the top of the watershed and has an 

 elevation of 148.8 meters. The view toward 

 the northwest from the station is remarkably 

 tine. Immediately after passing this station 

 the railway descends rapidly into the Para- 

 hyba valley. On this grade are many cuts in 

 red and yellow soft materials. Some of these 

 cuts are twenty meters or more in depth, and |-v-%j y,\[ th 



the sides stand at remarkably high angles. 

 Several of them half way down the grade 

 exhibit well-marked stratification of the mate- 

 rials. Plate XI shows the bedding in one of 

 these deep cuts.^ Some of the beds contain 

 unconsolidated, horizontal layers of white 

 quartz boulders from 0.3 to i meter in thick- 

 ness. These beds appear to rest upon and 

 against granites, and are overlain by clays 

 that exhibit but little or no evidence of stratification. In places 

 these clays are as much as fifteen meters deep. These strati- 

 fied beds appear to be a remnant of the same sediments as those 

 exposed along the railway between Maceio and Cachoeira. 



' This plate was kindly furnished me by Mr. Ambler, of the Alagoas Railway. 



