WOODWORTH: geological expedition to BRAZIL AND CHILE. 25 



red soils are not so common on this Triassic area as on the north in 

 Parana and Sao Paulo. The basalt has disappeared from a large tract 

 about Lages without leaving any noticeable trace. 



At 9:25 A.M. we came to the Rio Canoas which is here a broad deep 

 stream over which our pack-train was ferried on a platform supported 

 by four dug-out canoes and held to its course by a wire cable. On the 

 upland we passed the hamlet of Canoas with oxen ploughing. Shortly 

 before noon we descended a steep slope to a stream crossing with red 

 shales dipping north in the bank. Farther on the mule path trav- 

 erses a dike about seventy-five feet wide cutting the sandstones. 

 This dike is heavily charged with fragments of several rocks and min- 

 erals evidently brought up from below. About a mile farther south 

 a narrow dike about one foot wide occurs along the trail near a small 

 stream. About a mile farther south there is a short Ioav ridge on the 

 east of the road with small conical spurs and buttresses of inclined 

 beds on its north side. On approaching this point on the road with a 

 slight rain falling thousands of winged ants flew over the campo up to 

 fifteen feet in the air and for some reason chose to collect behind my 

 head in great numbers. On catching up with the party I found the 

 tent pitched in a clump of bushes at the western end of the ridge just 

 as a steady rain set in for the night. 



The small lakelets so characteristic of the trap surface also occur 

 in the sedimentaries south of the escarpment. Here the depressions 

 appear to mark the site of springs. From the dike southward the dip 

 is southerly and probably S. W. There is a small anticlinal fold near 

 this camp with axis NNW-SSE. 



August 27th. — It rained nearly all night and until 7 A. M. We 

 rode southward across the bleak campo to a descent over sandstone 

 beds which brought us, after a journey of fourteen days from Ponta 

 Grossa, into a broad irregular valley in which Lages lies. 



August 28th. — The light brown Triassic sandstone under a red 

 shale bed north of Lages is quarried for building stone and flagstones. 

 No fossils other than wandering trails were to be seen in the sandstone. 

 Certain greenish shale beds pass laterally and obliquely to the stratifi- 

 cation into red beds, and well-defined green-walled joints in the red 

 beds show that the green color is locally a post-depositional alteration 

 of the deposits. In the afternoon we returned northward, to the 

 locality of the dike bearing inclusions, for a more detailed study of 

 that rock. 



Ant-hills about fifteen inches high bestrewed the surface of the 

 Triassic sedimentary tract. As usual most of the hills had been 



