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WOODWORTH: GEOLOGICAL EXPEDITION TO BRAZIL AND CHILE. 13 
surface of the plateau, was the striking feature in the landscape. 
Long round swells or hills with graceful curves to the stream ways 
betokened everywhere the long continued action of erosion. The 
excellent topographic maps of this portion of the state by Mr. Horatio 
Williams begun by the Geological and Geographical Commission of 
Sao Paulo under the directorship of Dr. Derby made it possible to 
follow the route intelligently and interpret the general outlines of the 
erosive history of the district. In a following chapter on the geomor- 
phology of the region, I have made free use of these maps. 
July 25th— In 1908, the passenger service of the railway termi- 
nated at Bury, but a line in process of construction extended the 
communication by rail to Ponta Grossa in Parana, and so into connec- 
tion with points on the south far towards the boundary of Uruguay. 
As will be shown in the sequel the fresh cuttings of the rocks and 
surface deposits along this new line afforded an exceptional opportunity 
to study the geology not only of the underlying Permian tillite beds 
but also of the superficial gravels and their cover of red earths vari- 
ously known as terra roxa, ete. This day we proceeded on a flat car 
some 18 kilometers along the line of construction, completing the 
journey to I‘axina by a sort of carriage known as a “trolley.”” While 
traversing the high campos a hailstorm came up from the west with a 
well-defined horizontal vortical ring of black clouds, from which hail 
associated with rain fell so as to coat the ground with hailstones. 
For nearly an hour after the passage of the storm the small streams 
now in flood carried a thick load of hailstones. This fall of hail 
within the subtropical region at an elevation of 900 meters above the 
sea suggested an inquiry as to the occurrence of hail at lower eleva- 
tions nearer the equator as a possible factor in the Permian glacia- 
tion since it appears that in this way ice may be precipitated in 
regions where snow never falls. 
July 26th.— Being unable to secure a conveyance to Itararé, the 
day was spent in Faxina. This town is underlain by the Devonian 
sandstone, a light colored to whitish rock, with cross-bedded layers, 
and occasional bands of white quartz pebbles. Nodules of clay 
occur also embedded in the sandstone. The strata are well exposed 
in a ravine on the outskirts of the town. 
July 27th.— Having procured the means for the conveyance of our 
party to Sao Pedro de Itararé on the boundary of Parana, we journeyed 
to that place. For most of the day the route lay over the Permian 
basal sandstones which appeared in the stream bottoms, sometimes 
with thin beds of white quartz pebbles but without trace of compound 
