INVESTIGADORES
TROMBOTTO Dario Tomas
artículos
Título:
The Old Cryogenic Structures of Northern Patagonia: The Cryomere Penfordd
Autor/es:
DARIO TROMBOTTO
Revista:
ZEITSCHRIFT FUR GEOMORPHOLOGIE
Editorial:
GEBRUDER BORNTRAEGER
Referencias:
Lugar: Stuttgart; Año: 1996 vol. 40 p. 385 - 399
ISSN:
0372-8854
Resumen:
The processes of frezeeng and thawing that took place in the subregion
of Northern Patagonia during the Quaternary Cryomere, are revealed today by
traces of cryofragmentation, cryoturbation of polygons, ice wedge casts, folds,
irregular structures, etc. imprinted in the fluvial deposits of Patagonian
Gravel from the Plio-Pleistocene age and in the upper part of the Tertiary.
During and after the deposition of the Patagonian Gravel cryoforms were built
showing a characteristic structure related with the penetration and draining of
water, possible freezing, and with the drying and cracking of the active
paleo-layer. At the same time the cryogenic forms within the Patagonian Gravel
are related with the forming of calcrete or ?tosca?, which consists mainly of
CaCO3, quartzes and volcanic glass, giving the profiles their
characteristic periglacial image: a vertically and laterally heterogeneous
structure. This lithologic architecture of calcretes impregnating the
Patagonian Gravel, creates a network-like system of ?columns?, horizontal
layers and ?windows? according to the deposition and precipitation/or not
of CaCO3
which again each stand for different morphological types of calcretes. Puero
Madryn is an area that is very representativ of old cryoforms.