DEVEC land-sea interaction: evolution of ecosystems and climate”. Guide to the Field Meeting of the IGCP 499 IUGS – UNESCO

ACEÑOLAZA, G.F., VERGEL, M.M., PERALTA, S. AND HERBST, R.,

Instituto Superior de Correlación Geológica

Lugar: San Miguel de Tucumán; Año: 2007 p. 187

The Field Meeting DEVEC 2007 (IGCP 499 / UNESCO), was programmed to be held from June 14 to 22 in San Juan, Argentina. This is the first time Devonian specialists meet in an international gathering in South America, and in a country exhibiting, in the Precordillera and the San Rafael Block, large outcrops of Devonian sedimentary rocks, which are widely distributed either in the Gondwana hinterland and under deep discussion in the Patagonian region. A varied technical program is reflected in the range of submitted contributions. In a general sense, four basins should be recognized within Argentina: 1.      North Western basin: The so-called as NOA Basin embraces mainly Salta and Jujuy Provinces, where Devonian not highly fossiliferous strata outcrops as part of Eastern Ranges and Subandean Ranges. Herein, an almost complete succession of Devonian strata can be traced striking N-S as a southern continuation the Andes of Bolivia. 2.      Chaco-Paranense Basin: Placed in the Norh Eastern part of Argentina, embraces Western Salta, Santiago del Estero and Chaco Provinces, and the somehow disconnected Southern Buenos Aires Ranges. 3.      Precordillera of western Argentina: As part of the Cuyania terrane, they can be subdivided into two different regions, one with typical shelf facies, the Central Precordillera, where the stratigraphic sequence comprises, from the base upwards, the siliciclastic Talacasto and Punta Negra formations in San Juan Province, and the under revision Villavicencio Formation at Mendoza Province. The other region is located at the Western Precordillera of San Juan and Mendoza, where in the suggested Devonian deposits no fossil record has been done at present, in similar way that occurs in the Frontal Cordillera, at the Andes Hill. 4.      San Rafel Block, which forms together with the Las Matras Block, the southernmost extension of the Cuyania terrane. Herein, Devonian siliciclastic marine strata bears abundant trace fossil, with main outcrops in the Atuel Canyon. As an addition to the latter, intracratonic basins, open shelves, continental active margins and the cratonized areas are the framework where sediments were deposited during the Devonian. Finally, deformation and metamorphic events, as well as a large amount of igneous processes are also recorded during the Devonian, whether in Precordillera as well as in the neighbor terranes. The purpose of the field trips is to give to all the participants a general overview of the Devonian rocks from Argentina, and to generate field discussions on different aspects of our Devonian. A better general understanding of the sedimentary sequences is needed, to interpret the particular mosaic that we have in the Andean margin of South America.             The Devonian Period is one of the more significant and conspicuous in the Precordillera of Western Argentina, and has many distinctive characteristics, such as its geotectonic, paleogeographic and biostratigraphic features. The Devonian sedimentary sequence of the Precordillera includes olistostrome deposits which represent a widespread development of extensional basin. In order to review current research and develop strategies for future studies and international collaboration, the Field Meeting DEVEC 2007 of the IGCP 499 UNESCO, has been scheduled to be held mainly in the Precordillera of Western Argentina.             The precise recognition and definition of time in Stratigraphy is a continuing priority in geological research. This has been accentuated in recent years by the focus towards short-term geological and biological events in the stratigraphic record, being an important thrust of the Meeting the biostratigraphy, paleoclimate, paleoecology and palaeography. In this volume, authors from, Germany, United States, Check Republic, Turkey, Bulgary, Argentina, among others, submitted papers contributing to the Devonian Period knowledge.             These field trips and volume could not have been brought to fruition without the combined efforts of the following people: First, the authors and field trips leaders are thanked for their significant contributions leading the trips. We gratefully acknowledge the sponsors of the Field Meeting DEVEC 2007 of the IGCP 499-UNESCO: The Faculty of Exacts, Physics and Natural Sciences (FCEFN), National University of San Juan (UNSJ), National University of Tucumán (UNT), as well as technical assistance of the Vicente Mulet from National Council of Scientific and Technical Researches (CONICET), for its valuable help in different items related to the Meeting. Finally, I hope you enjoy this volume, and the Field Trips scheduled for the Meeting.