Geological Investigations In The Cordillera Of Tierra Del Fuego

The CADIC’s Geological Resources Program will soon turn 40 years of fruitful development. During this period many projects were carried out and others remain to be implemented. In the course of time three generations of researchers have been formed. Mentioning names would be unfair to those that could be involuntarily omitted. There is still a long way to go. The eagerness for knowledge should not stop. This book is a tribute to all those people who have worked in the different projects of pure and applied science, and educational, and human resources training, granted to this founding program and associated laboratories of the regional center of CONICET in Ushuaia, Tierra del Fuego, Argentina. The twenty papers which constitute this book have a genuine Latin appeal, having been written by 50 authors based in Argentina and Spain. All this contributions are concerned with Fuegian geological resources. Everyone concerned with this work hopes that it will prove a fitting and lasting memorial to Nacho Subías, whose personal contribution to our knowledge of this geology was outstanding.

This symposium, held in Argentina in March 2003, commemorates Otto Nordenskjöld’s 1901 expedition, and pays tribute to the Swedish and Argentinian explorers who took on the challenge of early fieldwork in Patagonia and Antarctica. This theme is extended to include recent fieldwork in the natural sciences in the Archipelago of Tierra del Fuego, the Antarctic Peninsula and the sub-Antarctic seas, and celebrates the fruitfulness of continuing Swedish-Argentinian scientific cooperation. The symposium and associated activities took place in the cities of Buenos Aires, La Plata and Ushuaia (Tierra del Fuego), and this book includes a selection of the most significant contributions presented at the meeting.

This book studies the Fuegian Andes in Argentina, showing both simple and complex aspects. The first ones refer to the general stratigraphy of the area and the latter result from their tectonic characteristics. Concerning the stratigraphy, an appraisal of the denomination and valorization of formations of Jurassic and early Cretaceous age is performed here to reach the simple scheme of the Fuegian-Patagonian continuity under the name of “Fuegian Andes Deformed Complex”. As an essay the formational nomenclature is simplified and the local concept of basement is evaluated. In relation to their structural aspects it is assumed that the formation of the orogenic Fuegian arc and the folding of the Mesozoic and early Tertiary layers are connected phenomena. Tectonic forces from the West, the Northeast and the South have had participation in the formation of the tectonic arc. The lithostatic column pressure was added once the layers were folded and thrusted upwards during the birth of the Fuegian Andes. Even the speculation of a great main fold overturned to North, as an abstraction, is considered. Instead, the Magallanes-Fagnano fault is appreciated only as a product of the transcurrent Quaternary movements, lacking associated eruptive processes that contribute to define plate borders.