THE HIGHESTTHE HIGHESTCENTRAL ANDESCENTRAL ANDES

Victor A. RamosVictor A. Ramos

Laboratorio de Tectónica AndinaLaboratorio de Tectónica AndinaUniversidad de Buenos AiresUniversidad de Buenos Aires

AconcaguaAconcagua

MercedarioMercedario

TupungatoTupungato

La RamadaLa Ramada

Cerro Aconcagua (6.965 m)Cerro Aconcagua (6.965 m)

Cerro Aconcagua (6.965 m)Cerro Aconcagua (6.965 m)

Pleistocene Volcano

VOLCÁN TUPUNGATOVOLCÁN TUPUNGATO(6.850 m)(6.850 m)

CENTRAL ANDESCENTRAL ANDES

ZONA DE BENIOFFZONA DE BENIOFFSUBHORIZONTALSUBHORIZONTAL

Cordillera PrincipalCordillera Principal

Cordillera FrontalCordillera Frontal

PrecordilleraPrecordillera

Sierras PampeanasSierras Pampeanas

ACONCAGUA FOLD AND THRUST BELTACONCAGUA FOLD AND THRUST BELT

Cegarra (1994)Cegarra (1994)

Juan Fern

ández Rid

ge

Juan Fern

ández Rid

ge

Sierras PampeanasSierras Pampeanas

BENIOFF ZONESBENIOFF ZONES

50 km

Mendoza

CórdobaSanJuan

BROKEN FORELAND BASINSBROKEN FORELAND BASINS

MAGNETOTELLURIC PROFIL OF SIERRAS PAMPEANASMAGNETOTELLURIC PROFIL OF SIERRAS PAMPEANAS

Booker et al. (2004)Booker et al. (2004)

PALEOZOIC TERRANES

Ramos (1994)Ramos (1994)

RÍO DE LA PLATACRATON

PAMPIA

CUYANIA

CHILENIA

PICHIDANGUI

TECTONIC EVOLUTION OF SIERRAS PAMPEANASTECTONIC EVOLUTION OF SIERRAS PAMPEANAS

COLLISIONCOLLISION

COLLISIONCOLLISION

COLLISIONCOLLISION

Quenardelle & Ramos (1999)Quenardelle & Ramos (1999)

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Rapela et al. (1998)Rapela et al. (1998)

Ramos (1988)Ramos (1988)

Based on:Based on:

• Gordillo (1984)Gordillo (1984)

• Patiño Douce (1987)Patiño Douce (1987)

• Jordan et al. (1988)Jordan et al. (1988)

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Rapela et al. (1998)Rapela et al. (1998)

METAMORPHISM:

M3: Low-P (2,5 to 4,0 Kb) Isothermal decompression

M2: High-T / Medium-P Regional metamorphism

M1: Medium grade Older foliation in garnets

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Rapela et al. (1998)Rapela et al. (1998)

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Age of high grade metamorphism:Age of high grade metamorphism: 1.- Migmatite with garnate where M2 has been established1.- Migmatite with garnate where M2 has been established with inherited zircon ageswith inherited zircon ages

U-Pb SHRIMP DATAU-Pb SHRIMP DATA

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Rapela et al. (1998)Rapela et al. (1998)

Last deformation D3:Last deformation D3: 2.- Monacite ages in granitoids2.- Monacite ages in granitoids

U-Pb SHRIMP DATAU-Pb SHRIMP DATA

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EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

GRANITOS PRECOLISIONALESGRANITOS PRECOLISIONALES

Rapela et al. (1998)Rapela et al. (1998)

PAMPEAN GRANITOIDSPAMPEAN GRANITOIDS

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Rapela et al. (1998)Rapela et al. (1998)

Tectonic setting of granitoidsTectonic setting of granitoids a) Small postectonic (post-D2)a) Small postectonic (post-D2) b) Metaluminous and peraluminous granitoidsb) Metaluminous and peraluminous granitoids

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Preorogenic granitoids (Early Cambrian)Preorogenic granitoids (Early Cambrian)

Rapela et al. Rapela et al. (1998)(1998)

Río SuquiaAscochinga

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

Postorogenic granitoids (Early Cambrian)Postorogenic granitoids (Early Cambrian)

Rapela et al. Rapela et al. (1998)(1998)

EASTERN SIERRAS PAMPEANASEASTERN SIERRAS PAMPEANAS

EARLY PALEOZOIC EARLY PALEOZOIC MAGMATIC ARCSMAGMATIC ARCSEAST OF CUYANIAEAST OF CUYANIA

• Late Proterozoic- Early Cambrian Late Proterozoic- Early Cambrian magmatic arc of eastern Sierras magmatic arc of eastern Sierras Pampeanas.Pampeanas.

• Late Cambrian - Ordovician magmaticLate Cambrian - Ordovician magmatic arc of western Sierras Pampeanas.arc of western Sierras Pampeanas.

• Ordovician magmatic arc of the Ordovician magmatic arc of the Famatina terrane.Famatina terrane.

The early Paleozoic is a period of The early Paleozoic is a period of accretion of different continental blocksaccretion of different continental blocks with development of magmatic arcs and with development of magmatic arcs and ophiolite obduction.ophiolite obduction.

Quenardelle y Ramos (1999)Quenardelle y Ramos (1999)

Pankhurst et al. (2000)Pankhurst et al. (2000)

WESTERN SIERRAS PAMPEANASWESTERN SIERRAS PAMPEANAS

PRE -, SYN -, AND POSTCOLLISIONAL GRANITOIDS

AA

CC

BB

DDFF

GGHH

EE

OPHIOLITE BELTSOPHIOLITE BELTS

• A. CalalasteA. Calalaste

• B. FiambaláB. Fiambalá

• C. Valle Fértil-C. Valle Fértil- Toro NegroToro Negro

• D. CortaderasD. Cortaderas

• E. Pie de PaloE. Pie de Palo

• F. Bosque AlegreF. Bosque Alegre

• G. VirorcoG. Virorco

• H. Athos PampaH. Athos Pampa

EARLYPALEOZOIC

BASAL TECTONITESBASAL TECTONITES

CUMULATOS IN GABBROS CUMULATOS IN GABBROS

Pillow-lavas in MORB tholeiitesPillow-lavas in MORB tholeiites

BASEMENT OF CUYANIA U-Pb in zircon ages

OlenellusOlenellus

LAURENTIAN FOSSILS

PROVENANCE OF THE CUYANIA SYNRIFT DEPOSITS

Corrected values after Finney (2004)

Ramos (2004)Ramos (2004)

ISOTOPIC CHARACTERISTICS OF CUYANIA

Groomet et al. (2003)Groomet et al. (2003)

COLLISION OF CUYANIA

Ramos (2004)Ramos (2004)

STAGES IN THE CUYANIA COLLISION

Ramos (2004)Ramos (2004)

PrecordilleraPrecordilleracarbonate platformcarbonate platform

Olistholiths Olistholiths

PRECORDILLERA FAMATINA

SHRIMP AGES OF K-BENTONITES AND GONDWANAN VOLCANIC ROCKS

Baldo et al. (2003)Baldo et al. (2003)

LAURENTIA GONDWANA

Many Thanks . . .Many Thanks . . .