GEOLOGY OF PERU—ADAMS. 897 
in Peru, since the localities are very near the border. D’Orbigny also 
referred the rocks at Arica to the Carboniferous on very slight evi- 
dence, but this has been refuted by Forbes. The writer found fos- 
sils at Arica, which, according to Bravo, are Cretaceous, although he 
did not determine them specifically. 
The Carboniferous areas examined by Forbes (1861) are on the 
peninsula of Copacabana and the projecting headland opposite on 
Lake Titicaca. On account of a declaration of war Forbes was placed 
i a suspicious position, since these localities are on the frontier be- 
tween Peru and Bolivia. He, however, obtained a collection of fossils 
which were determined by Salter. Forbes states that the Carbonif- 
erous is also to be found to the north of Lake Titicaca. 
The fossils collected by Agassiz (1876), together with some others, 
were studied by Derby (1876), who described 9 Carboniferous spe- 
cies from Yampata and the island of Titicaca. He also found a 
Spirifer in materials brought by James Orton from the Pichis River, 
and in his notes says that he has recognized Productus and Strepto- 
rhynchus from near Mayobamba in northern Peru. Agassiz, in the 
notes accompanying Derby’s paper, states that specimens of Fusulina 
were sent to Mr. Brady for identification. The notes as to the occur- 
rence of the Carboniferous are by Agassiz, who says that near Lake 
Titicaca it lies in a rather limited elongated basin, with the axis in a 
northwest-southeast direction. He identified the Carboniferous at 
Vilca, Santa Lucia, and Sumbay, and says that Mr. Orrego stated 
that Carboniferous is found as far north as Caylloma, and quotes 
Orton as saying that Raimondi reported he had traced the Carbonif- 
erous series to a height of 1,400 feet on the Apurimac at a locality 
intermediate between the Pichis River and Cuzco. It would seem to 
the writer that until fossils are found the identification of the Car- 
boniferous at the places mentioned by Agassiz, and especially those 
reported by Mr. Orrego, should not be definitely referred to the 
Carboniferous. The writer in journeying to Caylloma observed 
sedimentary formations which appear to be Cretaceous. 
Balta (1899) reviewed the Carboniferous of Peru and published 
a sketch map showing two areas in which the Carboniferous had been 
shown to exist, namely, in the Titicaca basin and the locality from 
which Orton’s Carboniferous fossils were obtained. He added noth- 
ing especially new. 
A small Carboniferous area was reported? by Fuchs (1900) as 
being found in the peninsula of Paracas, just south of Pisco, on the 
Pacific coast. The formation there contains some thin coal which 
@ See Boletin del Cuerpo de Ingenieros de Minas del Peru, No. 45, p. 19, 1906. 
% Nota sobre el Terreno Carbonifero de la peninsula de Paracas, FE. C. Fuchs, 
* Bol. de Minas, T. XVI, 1900. 
