372 THE CRETACEOUS AND TERTIARY GEOLOGY 



o-eoloo-v of tlie i-co-ion. These notes, however, were so few as not to be worth men- 

 tioning, except for the fact that lie afterwards made some valuable observations upon 

 the mesozoic geology of Ceara, and expressed the opinion that the Penedo sandstones 

 were "identical with those from the upper sandstones of Crato." 



Charles Darwin, in his " Observations," makes references to the mesozoic geology 

 of Pernambuco and Bahia, but he did not visit the coast between those places. 



In 1866, Prof Ch. Fred. Hartt touched at Aracaju, Maroim, and Penedo, and 

 gives the results of his obsci'vations in his " Geology and Physical Geography of 

 Brazil." He obtained a small collection of fossils at Maroim, but one of sufficient 

 importance to throw light upon the age of the rocks. He noted exposures at Sapn- 

 cary (by him called Sapueahy), Maroim, and through. Mr. Lane, who then lived at 

 Maroim, obtained specimens of Natica. The cephalopods of this collection were 

 described by Prof Alpheus Hyatt, and the descriptions published in Hartt's " Geol- 

 ogy and Physical Geography of Brazil," p. 385. "So explorations, whatever, had 

 been carried on inland, or even along the navigable parts of the streams. The facts 

 brought out in regard to the Sci'gipc-Alagoas region by Hartt are substantially as 

 follows : 



First. Reporting the following exposures : Estancia red sandstones, and the 

 limestones of Sao Gongalo, Sapucary, Maroim, Villa Nova, Penedo, Morro de Chaves. 



Second. Reference of the Maroim beds to the upper cretaceous, it is presumed, 

 upon the paleontologic evidence of Prof. Hyatt's descriptions of the cephalopods. 

 The desci'iptions of these fossils is the only work known to have been done upon the 

 fossils of the region up to that time. Prof. H^^att in his paper expressed no opinion 

 concei-ning the age of the beds, but what appear to be Hartt's field labels are given 

 as " from the cretaceous of Maroim." Such was our knowledge of the geology of 

 the region here treated of when the writer visited it as a member of the Commissuo 

 Oeologica do Brazil in 1876. 



TFIE GEOLOOIC IMPORTANCE OF THE SERGIPE-ALAGoAS REGION. 



Much of the l^razilian coast is very old geologically, no sedimentary beds to in- 

 dicate the changes through which this part of the continent has passed intervening 

 between the ocean and the granites and gneisses which are referred to the arehiean, 

 Along a considerable jjortion of the north-eastern coast, especially from Cape Sto. 

 Agostinho to Parahyba do Norte, soft sedimentary beds, provisionally referred to the 

 tertiary, are exposed here and there in abrupt blufls which, are being cut away by the 

 ocean. These rocks, however, although well exposed, have as yet yielded no fossils, 



