Project 574 - Bending and Bent Orogens, and Continental Ribbons
Understanding how map-view bends of mountain belts form and evolve is a first order Earth System problem and is the focus of this proposal. Earth’s great mountain systems, both modern and ancient, are characterized by significant map-view bends. The Bolivian bend (or Orocline) of the Andes is coincident with and formed at the same time as the Altiplano, Earth’s second greatest high plateau. Significant changes in Earth’s climate, including the onset of the most recent ice age, have been linked to the growth of the Altiplano. The bends (Syntaxes) adorning the western and eastern ends of the Himalaya are characterized by some of the greatest topographic relief on Earth, and are flanked by Earth’s two greatest mountains, K2 and Everest, respectively. The late Paleozoic Variscan mountain system that records formation of Pangea is characterized by a 180° bend in Iberian peninsula. The Iberian orocline is central and formed at the same time as a massive magmatic – thermal province that seeded much of the supercontinent with mineral deposits, and which, by weakening the crust, presaged Pangea’s eventual break-up. Hence the origin and evolution of bends of mountain belts is central to Earth’s climatic, topographic, and tectonic evolution. Furthermore, much of Earth’s budget of mineral deposits, and its thermal evolution (and hence its potential for hydrocarbons and other energy reserves) can be related to the formation of great bends of mountain systems. An improved understanding of the processes responsible for the formation of bent mountain systems therefore promises both scientific advances, such as an improved understanding of the mechanisms and processes responsible for plate tectonics and for changes in Earth geography through time; and directly applicable societal benefits, including refined models of climate and climate evolution, and increased exploration efficiency for both mineral deposits and hydrocarbon reservoirs.
Two main research directions are apparent:
(1) determining if the processes is responsible for the development of bent mountain belts, and
(2) documenting the geology and evolution of specific bends. Progress in both venues is to be achieved through a series (two per year over the five year course of the project) of field-based meetings in remote, developing regions, that can provide us with access to key mountain ranges. An added benefit of this work plan will be our ability to efficiently disseminate research advances and transfer knowledge into these developing regions.
Areas identified as key include:
(1) Andean South America;
(2) South-central Asia (Kazakhstan);
(3) the Caribbean region;
(5) the Gondwanides, including Patagonia, the Cape belt (S. Africa) and the Tasmanides (Australia);
(6) the Mediterranean-Alpine domain including the Rif of Morocco and related Betics of southern Spain, the Calabrian / Sicilian region of southern Italy, the Carpathian mountains, and the Isparta Angle (Turkey);
(7) the Cordillera of western North America; and
(8) the Variscides of western Europe. Results are to include the publication of field guides covering the geology of regions visited over the course of this project, refereed papers in international, high impact journals, and books published by national geological societies.
The project is multidisciplinary and will involve the collection and dissemination of data spanning the fields of paleomagnetism, geochronology, structural geology, stratigraphy and sedimentology, igneous and metamorphic petrology, geochemistry, paleogeography, geophysics, paleontology, tectonics and mineral deposit studies. Direct societal benefits will include improved understanding of the geological evolution of our specific target regions, and enhanced comprehension of the links between mountain systems, mineralization and hydrocarbon reserves. In addition, our project provides numerous opportunities for the transfer of knowledge into remote and developing regions, and for the involvement and funding of young, active researchers within these regions.