|
Four episodes of landscape evolution are recognized, each of which has led to the development of a regional erosion surface. The first phase began upon elevation of northern Chile above sea level in the late Mesozoic, and each subsequent phase commenced with a major incision of drainage into the preceding landscape. Radiometric dating of pyroclastic flows shows that the earliest elements of the present topography already existed in the Lower Eocene, and that most landforms had developed by the Middle-Upper Miocene. Deep canyon formation characterized the latest erosional phase which commenced in the Upper Miocene and is still continuing.
Tectonic elevation of the Cordillera de la Costa in relation to the longitudinal depressions seems to have occurred early in the landscape history, though later remobilization along major structures has since taken place.
Erosional landforms in the high Andes are often blanketed by constructional volcanic features and the migration of eruptive centres since Miocene times has displaced the continental watershed to the east.
Tectonically induced relative sea level changes have caused late Tertiary transgressive deposits in the littoral region to have been terraced during an irregular marine regression. The landscape history which spans the whole of the Tertiary indicates that Andean relief generation has been a prolonged pulsative process.
Supergene enrichment of the copper deposits took place under the older erosion surfaces between the Lower Eocene and the Upper Miocene, and the economic viability of a prospective mine can be largely predicted from the overlying topography.
This article has been cited by other articles:
 |
|
 |
|
  J. Benavides, T. K. Kyser, A. H. Clark, C. Stanley, and C. Oates Application of molar element ratio analysis of lag talus composite samples to the exploration for iron oxide-copper-gold mineralization: Mantoverde area, northern Chile Geochemistry: Exploration, Environment, Analysis, 2008; 8: 369 - 380. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Nelson, M. Nelson, K. Kyser, A. Clark, and C. Oates Carbon Isotope Evidence for Microbial Involvement in Exotic Copper Silicate Mineralization, Huinquintipa and Mina Sur, Northern Chile Economic Geology, 2007; 102: 1311 - 1320. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Arancibia, S.J. Matthews, and C. Perez de Arce K-Ar and 40Ar/39Ar geochronology of supergene processes in the Atacama Desert, Northern Chile: tectonic and climatic relations Journal of the Geological Society, 2006; 163: 107 - 118. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. X. Quang, A. H. Clark, J. K. W. Lee, and N. Hawkes Response of Supergene Processes to Episodic Cenozoic Uplift, Pediment Erosion, and Ignimbrite Eruption in the Porphyry Copper Province of Southern Peru Economic Geology, 2005; 100: 87 - 114. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Bouzari, F. Bouzari, and A. H. Clark Anatomy, Evolution, and Metallogenic Significance of the Supergene Orebody of the Cerro Colorado Porphyry Copper Deposit, I Region, Northern Chile Economic Geology, 2002; 97: 1701 - 1740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Bissig, T. Bissig, A. H. Clark, J. K.W. Lee, and C. J. Hodgson Miocene Landscape Evolution and Geomorphologic Controls on Epithermal Processes in the El Indio-Pascua Au-Ag-Cu Belt, Chile and Argentina Economic Geology, 2002; 97: 971 - 996. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Latorre, J. L. Betancourt, K. A. Rylander, and J. Quade Vegetation invasions into absolute desert: A 45;th000 yr rodent midden record from the Calama-Salar de Atacama basins, northern Chile (lat 22{degrees}-24{degrees}S) GSA Bulletin, 2002; 114: 349 - 366. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. P. Richards, J. P. Richards, A. J. Boyce, and M. S. Pringle Geologic Evolution of the Escondida Area, Northern Chile: A Model for Spatial and Temporal Localization of Porphyry Cu Mineralization Economic Geology, 2001; 96: 271 - 305. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. I. Mote, T. I. Mote, T. A. Becker, P. Renne, and G. H Brimhall Chronology of Exotic Mineralization at El Salvador, Chile, by 40Ar/39Ar Dating of Copper Wad and Supergene Alunite Economic Geology, 2001; 96: 351 - 366. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. I. Mote, T. I. Mote, G. H Brimhall, E. Tidy-Finch, G. Muller, and P. Carrasco Application of Mass-Balance Modeling of Sources, Pathways, and Sinks of Supergene Enrichment to Exploration and Discovery of the Quebrada Turquesa Exotic Copper Orebody, El Salvador District, Chile Economic Geology, 2001; 96: 367 - 386. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Gregory-Wodzicki and K. M. Gregory-Wodzicki Uplift history of the Central and Northern Andes: A review GSA Bulletin, 2000; 112: 1091 - 1105. [Abstract] [Full Text] [PDF]
|
|
