1913-] REGION ABOUT NATAL, BRAZIL. 447 



white limestones marked with streaks of red-brown. The hill above 

 these beds is covered with thick scrubby vegetation. The soil is 

 red and sandy, and lumps of the red iron-sandstone are scattered 

 over the surface, showing that the sandstone beds lie above the 

 limestones. 



Jacoca. 



Four kilometers southwest of Ceara-Mirim is situated the village 

 of Jacoca in the valley of one of the inlets of Lagoa Extremoz. On 

 the northern bank of the valley are two limestone quarries. These 

 expose about four meters of limestone beds overlain, in certain 

 places, by as many meters of the red-sandstones. The contact 

 between these two series of rocks is irregular and unconformable. 

 Each limestone bed is about a third of a meter in thickness, making 

 a total of twelve beds. These vary in their content of lime and 

 silica. Poor impressions of fossil shells are still left in the rock. 

 The material is almost pure white in color and is a magnesian lime- 

 stone with sand grains scattered through it. The contact line is 

 irregular and shows that the limestones once underwent the reduc- 

 tion of erosion before the sandstones were laid on top. Between 

 these beds and the sandstones is an area of black material which is 

 probably a deposition of manganese. Above these are whiter sand- 

 stones of soft character, and still higher up are the red sandstones, 

 characteristic of this latter series. On the surface of the ground are 

 scattered boulders of the red iron-rock. 



Masaranduha. 



The village of Masaranduba lies in the valley of Rio Guargiru, 

 an inlet to Lagoa Extremoz, on a road which leads from Macahyba 

 to Ceara-Mirim, about half way between these two cities. One kilo- 

 meter east of Masaranduba is a limestone quarry situated on the 

 bank of the valley. The beds in this place are practically horizontal 

 and unaltered. The exposure is four or five meters high. The 

 material is of very pure limestone. It is white, and almost devoid 

 of any fossil remains. On the hill above are loose pebbles of both 

 limestone and iron sandstone. 



PROC. AMER. PHIL. SOC., LH. 211 K, PRINTED SEPT. l6, I9I3. 



