CHAPTER V 
Detailed description of Coal Seams and Other Horizons in the 
Rio Bonito Beds 
No coal beds of any importance appear’ to occur in the lower 
half of the Rio Bonito beds, although some dark, plant-bearing shales 
and carbonaceous beds occur within 5 or 6 meters of the granite. 
One of these tossil-bearing shales occurs in a railway cut, between 
the 492nd and 4938rd kilometer post several kilometers south-west 
from Suspiro in Rio Grande do Sul, but the bituminous shale contains 
no genuine coal. Just above the dark stratum is a gray shale filled 
with Gangamopteris obovaia. 
This horizon, only 6 meters above the granite, is probably more 
than 100 meters below the horizon of the S. Jeronymo coal, since 
the latter does not-come in for 3 to 4 kilometers farther west. 
In the section at Minas, Santa Catharina, there is not a trace of 
coal visible in the 80 odd meters of sediments between the Bonito coal 
bed and the Orleans} conglomerate but the measures consist of alter- 
nate strata of sandstone and shales with a very rich plant-bearing 
horizon 65 meters below the top of the Bonito coal bed. 
Joaquim Branco Plant Bed 
Along the Estrada Nova, one-half kilometer north from‘the Railway 
station at Minas, and just below the cottage of Joaquim Branco, the 
writer discovered a thin stratum of yellowish sandy shale, very rich 
in fossil plants. The layer is only 20 to 30 centimeters in thickness, 
but from ita large collection was made, and sent to Mr. David White. 
the eminent Palaeobotanist of the U. S. Geological Survey, at Was- 
hington, D.C., who has studied and described these plants for this 
volume. Dr. White finds 3 new genera, and several new especies at 
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