SOMMAIRE / SUMMARY / SUMARIO Page On the significance of transversal wrench-fault tectonics for the structuring of the southern Central Andes. 1 Andreas ABELS Proterozoi-Iower Paleozoic terrane evolution in western South America. 6 Florencio Gilberto ACENOLAZA, Hubert MILLER and Alejandro Jose TOSELLI Discrimination between the various AMS plunges for the location of magma Chambers beneath the doleritic dykes of 8 Magdalena island, Southern Chile. Tahar AIFA, Jean-Pierre LEFORT and Francisco HERVE Late cretaceous fore-arc extension in northwest Peru: geodynamic implications. 13 Antenor M. ALEMÄN Transtensive Tectonic complications in the westem border of the Ecuadorian Andes: The Example of MINDO. 17 A. ALVARADO, S. BES DE BERC, M. SEBRIER and O. BELLIER, J.F. DUMONT Aftershocks of Cariaco-Venezuela Earthquake (Mw=6.9), July 9, 1997: Seismological analysis using a local network 21 Patricia ALVARADO, Arturo BELMONTE, Michael SCHMITZ and Enrique GAJARDO Evolution of Domeyko Range, Northern Chile. 25 Alejandro AMILIBIA, Francesc SÄBAT, Guillermo CHONG, Josep Anton MUNOZ, Eduard ROCA and Antonio RODRIGUEZ-PEREA The epithermal AU-AG ore deposits in the cordillera Shila, Southern Peru: Fluid inclusions and microfissuration data. 30 Anne-Sylvie ANDRE, Jacques L. LEROY, coworkers ofthe Peru 97-98 metallogeny GdR mission The Liquine-Ofqui fault zone: A case of deformation partitioning at obliquely convergent transpressional plate boundaries 34 (Southern Chile). Gloria ARANCIBIA, Gloria LOPEZ, Jose CEMBRANO Lithospheric structures in the southern central Andes, preliminary results (38° - 42°S). 38 Manuel ARANEDA, Maria S. AVENDANO, Hans Jürgen GÖTZE, Sabine, SCHMIDT, Jorge MUNOZ, Michael SCHMITZ Shallow seismicity in the north-western part of Argentina and ist relation with tectonics. 42 Mario A. ARAUJO, Graciela TELLO, Angel M. PEREZ, Irene PEREZ, Carlos A. PUIGDOMENECH Induced seismic activity by a glacier in volcanic areas: application to north flank of Cotopaxi volcano, Ecuador. 47 Sebastiän ARAUJO, Jean-Philippe METAXIAN Sedimentary record of the Salar de Atacama: Palaeohydrological implications 52 Virginia C. ARRANZ, Juan Jose PUEYO, Conxita TABERNER, Carles AYORA, Ramon ARAVENA and Guillermo CHONG D. Clockwise block rotations along the eastern border of the Cordillera de Domeyko, between 22°45' and 23°30' (Chile). 56 Cesar ARRIAGADA, Pierrick ROPERCH, Constantino MPODOZIS Shape and intrusion style of the coastal batholith, Peru. 60 Michael P. ATHERTON and Michael HAERDERLE Structure of the Merida Andes, Venezuela: Facts and Models 64 Felipe E. AUDEMARD M. and Franck A. AUDEMARD M. Style and timing of deformation in the Oriente basin of Ecuador. 68 Patrice BABY, Marco RIVADENEIRA, Frederic CHRISTOPHOUL and Roberto BARRAGAN Magma evolution processes at the Tatara-San Pedro complex: 36°S, southern volcanic zone (SVZ), Chilean Andes. 73 Jenni BARCLAY, Andrea MARZOLI, Michael DUNGAN A cretaceous hot spot in the Ecuadorian Oriente Basin: Geochemical, Geochronological and Tectonic Indicator. 77 R. BARRAGAN and P. BABY Shear wave velocity in the lithospheric across the central Andes. 82 David BAUMONT, Anne PAUL, Helle PEDERSEN, George ZANDT and Susan BECK The cause of thick. Slow crust in the Altiplano, central Andes: Melt or Composition? 86 Susan BECK, Jennifer SWENSON and George ZANDT The tectonic evolution of the Mesozoic and Cenozoic auslral basin of southcrn South America. 90 C. Mike BELL , Rita DE LA CRUZ and Manuel SUÄREZ A grain-size Classification: igneous and metamorphic rocks under the Standard petrological T L. microscopc. 94 Ludwig BIERMANNS Nd + Pd isotopic composition of Paleozoic rocks of NW-Argentina and N-Chile: Crustal growth and dynamics in the 98 Andes from Ordovician to Permian times. B. BOCK, BAHLBURG, H.. WÖRNER, G., and ZIMMERMANN, U. Andean transpressive tectonics at the eastem edge of the Cordillera Oriental, Colombia. 103 Yannick BRANQUET, Alain CHEILLETZ, Peter R. COBBOLD, Patrice BABY, Bernard LAUMONIER, Gaston GIULIANI Tectonic Model of the North Subandean Zone, Ecuador. 106 A. BUITRON PEREZ Management of geoscientific information: The Website of the SFB267 110 Heinz BURGER, Michael ALTEN and Sabine MOHR Extension in the Southern Andes as evidenced by an Oligo-Miocene Age intra-arc basin. 115 W. Matthew BURNS and Teresa E. JORDAN Seismic swarm in Quito (Ecuador): Tectonic or volcani origin? 119 Alcinoe CALAHORRANO. Hugo YEPES, Bertrand GJUXIER, Mario RUIZ, Monica SEGOV1A, Darwin VILLAGÖMEZand Daniel ANDRADE Fluid inclusions study in Marte Porphyry Gold Deposit, Copiapo Chile. 123 Eduardo CAMPOS Characterization of fluid inclusions from zaldivar Porphyy Copper, Chile. 127 Eduardo CAMPOS and Jacques R. L. TOURET Post eocene deformational events in the north segment ofhe Precordilleran fault system, Copaquiri (21°S). 132 Pedro CARASCO, Hans-Gerhard W1LK.E and Heinz SGNE1DER. Last miocene-quarternary stratigraphy and tectonic of th eastem part of the Madre de Dios foreland basin (SE Peru). 136 Jose CARDENAS, Victor CARLOTTO, Darwin ROMBO, Waldir VALD1VIA, Wilber HERMOZA, Luis CERPA, Omar LATORRE, Miriam MAMANI Sedimentary and structural evolution of the Eocene-Oligocene Capas Rojas Basin: Evidence for a late Eocene lithospheric 141 delamination event in the southern Peruvian Altiplano. Victor CARLOTTO, Gabriel CARL1ER, Etienne JAILLARD, Thierry SEMPERE and Georges MASCLE GIS Andes: A metallogemc GIS of the Andes Cordillera 147 D. CASSARD Crustal-scale-pop-up structure at the Southern Andes plat boundary zone: A kinematic response to Pliocene transpression. 151 Jose CEMBRANO, Alain LAVENU, Gloria ARANCIBl, Gloria LOPEZ and Alejandro SANHUEZA Opposite thrust-vergencies in the Precordillera and westei cordillera in northern Chile and structurally linked cenozoic 155 paleoenvironmental evolution. Reynaldo CHARRJER, Gerard HERAIL, John FLYNN, lodrigo RIQUELME, Marcelo GARCIA, Darin CROFT and Andre WYSS Process of formation of the Au-Ag Shila-paula epithermal veins system (southern Peru) 159 Alain CHAUVET, Daniel CASSARD and Laurent BAILLY Ore and rock Lead isotope compositions witness geodynaimic events in the Ecuadorian Andes. 163 Massimo CHIARADIA and Lluis FONTBOTE Descrimination of eustatic and tectonic influences in the Ecuadorian Oriente Basin from Aptian to Oligocene times. 168 Frederic CHRISTOPHOUL, Patrice BABY and Celso DAVILA Multifractal analysis of the 1995 Antofagasta, Northern Chile earthquake. 172 D. COMTE, Aemando CISTERNAS, Louis DORBATH, Jaime CAMPOS, Jean Paul AMPUERO III A double-layered seismic zone in Arica, Northern Chile. 176 D. COMTE, Louis DORBATH, Mario PARDO, Tony MONFRET, Henri HAESSLER, Luis RIVERA, Michel FROGNEUX, Bianca GLASS, Carlos MENESES The Wadati-Benioff Zone around Copiapo, northern Chile using locally recorded data: Preliminary results. 180 Diana COMTE, Louis DORBATH, Bernard PONTOISE, Mario PARDO, Tony MONFRET, Henri HAESSLER, Yann HELLO, Yvan JOIN, Emilio LORCA, Alain LAVENU The crustal structure in the region of the 1997 Cariaco earthquake, eastern Venezuela, based on seismic refraction and 184 gravimetric data. Rommel CONTRERAS, Michael SCHMITZ, Leonardo ALVARADO, Jesus CASTILLO, Stefan LÜTH Quaternary deformations and seismic hazard at the Andean Orogenic Front (3 r-33°, Argentina): A Paleoseismological 187 Perspective. Carlos H. COSTA, Thomas K. ROCKWELL, Juan D. PAREDES, Carlos E. GARDINI Cenozoic deformation and tectonic style of the Puna Plateau (Northwestern Argentina, Central Andes). 192 Isabelle COUTAND, Peter COBBOLD, Annick CHAUVIN, Eduardo ROSSELLO, Oscar LOPEZ-GAMUNDI Age and Petrology of Tusaquillas plutonic complex on the evolution of Cretaceous rift in NW Argentina. 197 Chiara CRIST1ANI, Aldo DEL MORO, Massimo MATTEINI, Roberto MAZZUOLI, Ricardo OMARINI Neogene evolution ofthe main Ecuadorian fore-arc sedimentary basins and sediment mass-balance inferences. 201 Yann DENIAUD, Patrice BABY, Christophe BASILE, Martha ORDONEZ, Georges MASCLE and Galo MONTENEGRO Nevados de Chillän and Antuco volcanoes (Southern Andes) revisited: a remarkable example of magmatic differentiation 206 through closed-system crystal fractionation. Bernard DERUELLE and Leopoldo LÖPEZ-ESCOBAR Lower Holocene plinian eruptions of Cotopaxi volcano - Ecuador 210 DESMULIER, F., ROBIN, C. and MOTHES, P. A. Evidence for the latest Ordovician / early Silurian glaciation in the Peruvian Altiplano: tectonic implications. 214 Enrique DIAZ-MARTINEZ, Harmuth ACOSTA, Rildo RODRIGUEZ, Victor CARLOTTO and Jose CARDENAS 207Pb/206Pb and59Ar/40Ar geochronology of metamorphic costal belt between 41° and 42°S in the Andes. 219 Paul DUHART, Jorge MUNOZ, Michael McDONOUGH, Mark MARTIN and Michael VILLENEUVE The Tatara-San Pedro volcanic complex (36°S, Chile): Implications for arc magma genesis and evolution in the southern 224 volcanic zone of the Andes. M.A. DUNGAN Volcanogenic Sedimentation model for the Miocene Farellones, Andean cordillera, Central Chile. 228 Sara ELGUETA, Reynaldo CHARRIER, Ramön AGUIRRE, Guy KIEFFER, Nicole VATIN-PERIGNON Monitoring geophysical and geochemical data at the volcano Galeras, Colombia. 232 E. FABER, S. GREINWALD, D. PANTEN, G. G. VALENCIA, D. M. GÖMEZ, R. A. TORRES, C. MORAN and A. O. ESTUPINAN The neogene transpressional architecture of the Santa Elena Peninsula, Ecuador: new insights from seismic data. 235 Fernando A. FANTIN, Patricio MALONE, Eduardo A. ROSSELLO and Muriel MILLER Origin of crystal clots and their orthopyroxene-titanomagnetite symplectites in lavas from the Lincancabur volcano, South- 240 Central Andes. Oscar FIGUEROA and Bemard DERUELLE Decompression