RESUME OF GEOLOGY ALONG SAO FRANCISCO RAILWAY 75 



sedimentary basins seen by him are completely metamorphosed and 

 contain no fossils. He makes no mention, however, of the location of 

 such sedimentary rocks. 



The rocks about Panellas, north of Quipapa, he found to be fine- 

 grained gray granites. At Pesqueira, northwest of Garanhuns, he found 

 granites, and the Serra de Ororoba, near Cimbres, he found to be of 

 granite exposed in solid rounded peaks.* 



Between Pesqueira and Sao Bento he found only granites. t In the 

 vicing of Bom Conselho (Papacaca) he found " everywhere the same 

 terrane of granite or porphyry,"! while at Ipueiras, southwest of Bom 

 Conselho, he reports gneiss and schist and an " irregular bed of white 

 crystalline limestone." 



RESUME OF THE GEOLOGY ALONG THE RECIFE AO SAO FRANCISCO RAILWAY 



The crystalline rocks through the region of the Recife ao Sao Fran- 

 cisco railway are much faulted. These rocks are chiefly granite, gneisses, 

 and schists. 



West of Canhotinho a few exposures look like sedimentary rocks, but 

 these beds were not carefully examined and it may be that the appear- 

 ance of bedding is due to metamorphism. 



The strike of the beds (or the schistosity ?) is somewhat constant along 

 the northeastern half of the railway line, but farther west the dip and 

 strike vary greatly in amount and direction. These changes are enough 

 to show that no trustworthy conclusions can be drawn from similarity 

 or dissimilarity of dip and strike in widely separated districts in the 

 Paleozoic regions of Brazil. 



It is still supposed by some people living in the state of Pernambuco 

 that the rounded bosses of granite and the great rounded boulders found 

 over the hilltops along the line of this railway are of glacial origin. 

 This is quite erroneous. The theory at one time advocated by Louis 

 Agassis and by Belt that this part of South America was covered by ice 

 during the glacial period has been shown to be untenable. These par- 

 ticular boulders originated where they now lie, unless they may in 

 some instances have rolled down the hillsides. Such boulders occur 

 between Cabo and Ipojuca, 300 meters east of Olinda station (kilometers, 

 45), about Timbo-Assu, and at many other points along the railway. 



Decomposition of the rocks is widespread, but the depths of the de- 

 composition exposed in the railway cuts along this railway does not 

 exceed 20 meters. 



The sedimentary beds north and west of Buique have yielded no fossils, 



* Loe. eit., p. 81. fLoc. eit., p. S3. J Loc. eit,, p. 37. 



