VARIABILIDAD LITOLÓGICA Y ARQUITECTURAL EN SISTEMAS TURBIDÍTICOS CANALIZADOS DEL PALEÓGENO, ANDES FUEGUINOS. IMPLICANCIAS EN LA TRANSFERENCIA SEDIMENTARIA A LA CUENCA
Description: 10 p. ; 169-178DDC classification:- 068.82 553.28 C62 15730
| Current library | Call number | Status | Barcode | |
|---|---|---|---|---|
| Biblioteca virtual | 068.82 553.28 C62 15730 (Browse shelf(Opens below)) | Not for loan | 200068616 |
In the Fuegian Andes, Paleogene foreland strata within the thrust-fold belt of the Austral-Malvinas basins are organized into thick axial and transverse turbidite systems. The axial systems are dominated by channel-levee complexes, which are characterized by marked lithological and architectural changes along their dominant east-southeast sedimentary dispersion. These changes are observed in very thick channelized sandstone-mudstone successions at different scales, from tens of meter-thick packages to decimeter-thick individual beds. Regardless of the scale, most of them are characterized by erosive surfaces preserving residual pockets of coarse-grained sand, gravel, and shell fragments. At the smaller scale, these features are interpreted as reflecting the passage of highly energetic gravity flows, which scoured channel floors leaving behind a lag of the coarser transported sedimentary load. At the largest scale, the lateral, abrupt passage from thick sandstone-rich packages to well-bedded muddy packages are thought to represent either 1) the coincidence at the same stratigraphic level of different elements of meandering channels –e.g. levee and channel facies— or 2) channel avulsion, followed by up-current erosion and downcurrent deposition of thick-sandstone packages (avulsion lobes or HARPs) while the channel equilibrium profile is restored. In this paper we document and interpret these features, commenting on their significance for the sedimentary transfer from the Fuegian Andes to the Malvinas Basin and pointing to the reservoir potential of thick sandstone packages encased in mudstone.



