76 SIERRA DE UMANGO 
ducts of the lower Gondwana members are represented in the form - 
of boulders. The „grey psammite* of Bodenbender could not ; 
be the real „graywacke“ of glacial origion but must correspond to — 
the upper, pale-coloured, psammitic layers of the lower Gondwana. 
a 
Then follows over the „gray psammite“ a red, apparently triassic j 
sandstone. 
As to the writers studies of the strata in the profiles along the 
Quebrada Banda Florida and the dry gorge of the Rio de los 4 
Noques, running along the inside of the bordering sandstone mantle, 
the succession here is: over the crystalline rocks (quartzite schist) 
Fig, 11. An erosion remnant of red Gondwana sandstone, lying on a" tilted 
crystalline basement block. Looking north from the Cerro Punta Colorada, eastern 
side of the Cerro Villa Union. { 
lies a pale yellowish sandstone as the lowermost member. The li- 
thological character of this rock shows a great resemblance with 
the lower pale sandstones in the Cerro Guandacol profile. A distinct 
crosscurrent bedding reminds one much of the pelodite-sandstones 
in the classic profile at Jachal, containing small scattered boulders 
too. This sandstone is succeeded by a pale brown sandstone of 
psammitic character, overlaid with a mighty, very coarse conglome- 
rate of dark brown colours. The boulders of this conglomerate, 
well waterworn and lying stratified with sandy interstratifications, 
all consist of old crystalline rocks. Upward follows then a mighty 
