92 SIERRA DE UMANGO 
layers are known except small remnants on the Cerro Punta Co- 
lorada and the Cerro Potrero Viejo. On the Famatina side there 
are, however, several of this kind. 
Over these strata follows without unconformity a series of crom- 8 
red and upward redbrown sandstones with numerous conglomeratic 4 
interstratifications. Already long ago this series has been regarded by 
Bodenbender of triassic or Damuda age. The circumstance, that 
these beds lie in some parts directly over the crystalline basement, 
orogenetic movements!, as is evident from the conformity between 
these and the underlying pale-coloured sandstones and slates. 
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shows, that a pretriassic erosion took place, but without preceeding © 
The triassic red beds seems to have a considerable extension in — 
the Umango area, although it is difficult to state if the strata in - 
some parts really belong to the triassic. As shall be seen, the 
upper layers in the continental series have often similar characte- 
ristics. 
The development of the red beds on the Famatina side is a con- 
siderable one, appearing in most „grabens“ there and also on the 
crests up to great heights. 
The fact that the conglomerate layers in i these triassic and younger 
strata carry boulders of the old crystalline rocks indicates, that 
judging from the thickness of the layers the pretriassic erosion reached 
the crystalline basement in some parts to a greater depth. 
The red beds change upward into brown sandstones of similar 
consistence. They seem to be of a considerable thickness. It is 
interesting to find, that the brown strata occur only in the ,inter- 
montane zone“ to its whole length, but in no other part of the 
Umango area. For instance in the mighty succession of the Cerro 
Guandacol — Cerro Bola-profiles no brown beds are visible. But 
in the NNE continuation of the „intermontane zone“ in the mountains 
1 It may be spoken later on about the influences of the permian andean move- 
ments here. They are in fact very insignificant. 
