GENERAL AND ECONOMIC GEOLOGY 257 



observations on its many geologic problems are nnusually difficult to 

 harmonize, and the results as shown on the map must not be regarded as 

 anything more than an effort to bring them into accord with each other 

 and with what is known of the geology of adjoining regions. The few notes 

 I have been able to find on the geology along the Eio Guapore are by Dr. 

 Joao Severiano da Fonseca.^^ The geology along the Gy-Parana and the 

 Eio Theodoro is chiefly from the notes and reports of Euzebio Paulo de 

 OJiveira.^* The general geology of the Serra do Norte and of the plateau 

 west of Diamantino is also chiefly from his paper. 



The Parcels sediments (Cretaceous?) are shown on the map as cross- 

 ing Eio Tapajos about seven degrees south latitude, in accordance with 

 the notes of Chandless.^^ On the upper Xingii we have a very few notes 

 in the papers of Dr. P. VogeP^ and of Otto Clauss.^^ The Parcels sand- 

 stone of the plateau is referred provisionally to the Cretaceous, in ac- 

 cordance with the suggestion of Euzebio Paulo de Oliveira, though, as he 

 points out, no fossils characteristic of that age have yet been identified 

 from that series. ^^ This agrees also with an earlier suggestion of Derby, 

 made in 1895 and based on vertebrate remains found in the horizontal 

 sandstones north of the Chapada.^^ 



The geology of the southwestern part of the state is chiefly from the 

 report of Dr. M. A. E. Lisboa.^^ Some light is to be had on that part of 

 the state, however, from what has been published on the geology of Para- 

 guay. Near Yilla Eica Stereosternum tumidum,^'^ a fossil characteristic 

 of the Upper Permian of Brazil, has been found, while in the mountains 

 of northeastern Paraguay have been found Prochicfus and Spirifer posf- 

 striatus, fossils characteristic of the Permian.®- These fossils suggest the 

 possibility of the "Bodoquena" of Dr. Lisboa being Permian, in part at 

 least.®^ 



53 viagem ao i-edor do Brazil, vol. ii. Rio de .Janeiro. 18S1. 



^ Reconliecimento geologico do Noroeste de Matto Grosso. 



^ W. Chandless : Notes on the rivers Arinos, .Turuema. and Tapajos. .Journal Royal 

 Geograpliical Society, vol. xxxii. pp. 268-280. London. 1862. 



38 P. Vogel : Reise in Matto Grosso, 1887-8. Zeit. der Gessellschaft fiir Erdkunde zn 

 Berlin, xxviii, Berlin, 1893 ; also in Yon den Steinen's Erforschung des Xingu : durch 

 Zentral-Brasilien, Leipzig, 1886. 



3^ Otto Clauss : Bericlat iiber die Schingu-Expedition. 1884. Petermann's Mittheil.. 

 vol. 32, 1886, pp. 129-134. 162-168. 



3^ Expedicao scientifica Roosevelt-Rondon. Annexo no. 1 Geologia. pp. 33, 76. Rio de 

 Janeiro, 1915. 



5» Archivos do Museu Nacional, vol. ix, p. 63. Rio de .Janeiro. 189,5. 



''o Oeste de Sao Paulo, Sul de Matto Grosso. Geologia, etc. Rio de Janeiro, 1909. 



61 F. Freeh : Lethea Geognostica, Th. i. 2 Bd.. Lief 3, p. 460. 



82 Jos. V. Siemiradski : Geologische Reisebeobachtungen in Siidbrasilien. Sitz. Akad. 

 Wiss. Wien, vol. cvii, January, 1898, pp. 38-39. 



83 This is still further strengthened by a report of fossil ferns said to have been found 

 near Miranda by Lloyd and cited by Evans. Quarterly Journal of the Geological Society 

 of London, p. 97. London, 1894. This announcement seems to have been discredited, 

 and I have not yet been able to verify the statement. 



