Page:Through the Brazilian Wilderness by Theodore Roosevelt (1925).djvu/263

 honey-creeper. In Colombia Miller found the honey-creepers habitually coming inside the houses and hotels at meal-times, hopping about the table, and climbing into the sugar-bowl.

Along this part of our march there was much of what at a hasty glance seemed to be volcanic rock ; but Oliveira showed me that it was a kind of conglomerate, with bubbles or hollows in it, made of sand and iron-bearing earth. He said it was a superficial quaternary deposit formed by erosion from the cretaceous rocks, and that there were here no tertiary deposits. He described the geological structure of the lands through which we had passed as follows: The pantanals were of pleistocene age. Along the upper Sepotuba, in the region of the rapids, there were sandstones, shales, and clays of permian age. The rolling country east of this contained eruptive rocks—a porphyritic diabase, with zeolite, quartz, and agate of triassic age. With the chapadão of the Parecís plateau we came to a land of sand and clay, dotted with lumps of sandstone and pieces of petrified wood; this, according to Oliveira, is of mesozoic age, possibly cretaceous and similiar to the South African formation. There are geologists who consider it as of permian age.

At Vilhena we were on a watershed which drained into the Gy-Paraná, which itself runs into the Madeira nearly midway between its sources and its mouth. A little farther along and northward we again came to streams running ultimately into the Tapajos; and between them, and close to them, were streamlets which drained into the Dúvida and Ananás, whose courses and outlets were unknown. This point is part of the divide between