I "Thy. *-">-> [May 16, 



with strips and patches of forest. In the southern portion of the province 

 oue such area, of considerable size, extends from the Serra do Mar to the 

 margin of the second region, and reaches northward to beyond the capital, 

 Curityba. Another and much smaller area exists to the west of the second 

 range of mountains, in the north of the province, about the city of Castro. 

 This last is generally included in the second region, under the name of the 

 Campos Geraes, but geologically it has nothing in common with those carn- 

 pos, and belongs to the first region. 



The rocks of this region are all metamorphic, the beds being highly 

 inclined, with a general strike E. N. E. Along the coast and in the Serra 

 do Mar granite, porphyritic and schistose gneisses occur, as in the corres- 

 ponding region of the province of Rio de Janeiro, with an abundance of 

 igneous rocks, including diorite, porphyry and a compact variety with a 

 basaltic structure. In the plains about Curityba epidotic rock occurs abun- 

 dantly, with schistose gneiss ; while farther west the latter is associated 

 with metamorphic, noncrystalline, red schists, which are either talcose or 

 hydromica, and with red, metamorphic porphyry, which is a more meta- 

 morphosed portion of the same schists. In the plains about and to the 

 west of Curityba a thick deposit of decomposed material covers the rock 

 and good exposures are rare. The rocks seen in situ are those above men- 

 tioned, but an abundance of pebbles of itacolumite and other varieties of 

 quartzite attest the existence of other rocks in the vicinity. 



Unfortunately I was unable to visit the northern mountainous portion of 

 this region, about the head-waters of the river Ribeira, which is by far the 

 most interesting part of the metamorphic belt. In the western margin of 

 this district, which is known by the general name of Assunguy, I found 

 the red schists and porphyries, above mentioned, extensively developed, 

 with beds of white marble and iron ore. From the specimens and 

 information I was able to obtain from this region, it appears to be 

 very rich in marbles, iron ores and auriferous rocks. From about fif- 

 teen miles north of Curityba, I saw a greenish serpentine marble, iden- 

 tical with that associated with the same red schists near Sorocaba, province 

 of Sao Paulo, and from other portions of the Assunguy region, I saw 

 specimens of itacolumite and of the peculiar auriferous, ferruginous quartz- 

 ite called Jacutinga, so characteristic of the metamorphic region of Minas 

 Geraes. These specimens, and the few observations I was able to make, 

 confirm the opinion I had already formed, that the non-crystalline meta- 

 morphic series, composed of quartzites (itacolumite, itabirite, jacutinga, 

 etc.), talcose (hydromica?) schists and marbles,* so characteristic of the 

 interior of the provinces of Bahia and Minas Geraes, extend in a continu- 

 ous belt to the southward, probably as far as Rio Grande do Sul, presenting 

 everywhere the same essential characters. 



I have elsewheref presented reasons for referring the crystalline meta- 



*The crystalline marbles formavery subordinate part of the series, which, for 

 convenience, I cull non-crystalline, to distinguish it from the older crystalline 

 series, composed of gneisses, etc. 



i Proceedings, American Philosophicnl Society, pane Ifil above. 

 Archivos do Museu Nacional, Rio de Janeiro, Vol. It, 1878. 



