Newly discovered Jurassic skarnfields in the Ecuadorian Andes

Autor: B. Beddoe-Stephens, M. Litherland, N.J. Fortey
Rok vydání: 1992
Předmět:
Zdroj: Journal of South American Earth Sciences. 6:67-75
ISSN: 0895-9811
DOI: 10.1016/0895-9811(92)90018-t
Popis: A series of calcic magnetite skarn klippen in the north of the Cordillera Real are interpreted as erosional relics of a great skarn sheet, over 150 km long, formed by thrusting of island-arc type sediments and volcanics over the Jurassic Azafran batholith during an accretion event. The skarns are contrasted petrographically and compositionally with those of the Nambija field in the south of the Cordillera, which probably relates to the same chain of batholiths. However, the Nambija skarns are autochthonous and rich in gold, with Au:Ag ratios in the region of 20:1, whereas those to the north are allochthonous and relatively barren.
Databáze: OpenAIRE