428 Lishoa — Permian Geology of Northern Brazil. 



dicotyledonous woods. Diabasic eruptive rocks of different 

 types were also discovered, occurring in a manner similar to 

 those in the south of Brazil. In the absence of paleontologic 

 evidence, these eruptives suggest the provisional placing of 

 certain overlying reddish sedimentary beds in the Triassic. 

 The area of Cretaceous sediments in the states of Piauhy, 

 Maranhao, and Goyaz has been considerably limited. For the 

 greater part, the interior of the first two of these states and a 

 large part of the third is made up of upper Paleozoic and lower 

 Mesozoic sediments which only future study and paleontolog- 

 ical studies can definitely outline. 



Localities of Fossils. 



In the course of the exploration many fossiliferous localities 

 were discovered. Most of them are referred to here. 



1. Marine mollusca. — Marine shells were seen in Caruta- 

 pera, between Turyassu and Gurupy, on the western part of 

 the coast of Maranhao. They are of Cretaceous age, and very 

 probably of the same geological horizon as those of Piabas 

 in Para. 



2. Dicotyledonous woods. — Silicified woods were found in 

 the high plateau regions of Grajalm and Mearim. These plants 

 are of common occurrence in this region, and are well known 

 to the inhabitants. They are called Capitdo do Campo (Cap- 

 tain of the campo), which is the name given to a tree common 

 in the campos of the north. Specimens were collected in place 

 at the following localities : 



(a) At Fazenda do Torto, nine kilometers from the city of 

 Grajahti, I made a collection of material in place. The speci- 

 mens sent to the Servico Geologico are parts of a large trunk 

 imbedded in grayish quartzitic sandstone five meters below the 

 surface of the ground. In certain parts of the trunk, deeply 

 buried and attached to the sandstone, could be seen zones of 

 different textures and colors, crossing indifferently the quartzite 

 and the silicified trunk. This indicates that the silicification in 

 this particular case occurred where the fossil was found ; its 

 original resting place was therefore the quartzitic sandstone 

 of Torto. 



(b) Fazenda da Coelho, twenty-four kilometers down the 

 river north of Grajahu. 



(c) Fazenda Monte Alegre, twelve meters to the northwest 

 of Grajalm. 



(d) Fazenda da Extrema, six kilometers to the south of 

 Grajahu. 



In these localities all of the specimens found are of dicotyle- 

 donous woods. 



