ANDES2019

EXCURSION

CONTINENTAL ARC VOLCANISM ON THICK, OLD, HOT CRUST

GEOLOGY, VOLCANOLOGY AND PETROLOGY ALONG A TRANSECT FROM ARICA TO VOLCAN TARAPACA AND PARINACOTA

Active continental margins are shaped by subduction-related magmatism, and the Central Andes of South America are a prime example. The “modern” Andean orogen with its present elevations and landscape characteristics has evolved over the past 25 My. The excursion provides insight into the orogenic processes that formed the Central Andes: uplift, erosion, and climate history of the Atacama desert, a region that is exceptional for its magnificent geological scenery, beautiful landscapes, traditional towns and wildlife.

IMPORTANT

Arica airport

Sept. 28 - Oct. 7, 2019

Field leader: Gerhard Wörner

Georg August Universität, Göttingen

PROGRAM

Day 1 (28-Sept)

Arrive to Arica airport, lodging at Hotel Amaru.

Rafael Sotomayor 490, Arica, Chile

+56 (58) 222 4444

ventasyreservas@hotelamaru.cl

Day 2 (29-Sept)

Arica - Putre: Introduction: Geology and tectonics of the Central Andes; Azapa Valley: stratigraphy, tectonics, ignimbrites, erosion, and sedimentation on the margin of the Western Cordillera.

Lodging at Hotel Chacana, Putre at 3500 m elevation.

Day 3 (30-Sept)

Belen basement: Oldest rocks in Chile, tectonics and gravitational collapse on the western margin of the Altiplano.

Day 4 (01-Oct)

Salar de Surire: Lake sediments and salars on the Altiplano, borax deposits, hotsprings and wildlife (flamingos, vicuñas, ñandus, condors).

Day 5 (02-Oct)

Lauca-Basin, Chapiquina: Miocene Lauca Basin sediments, Lauca and Oxaya Ignimbrite

Day 6 (03-Oct)

Tarapaca dacite dome complex, stratigraphy, pyroclastic deposits. Petrology of dacites and its sanidine megacrysts.

Day 7 (04-Oct)

Parinacota stratigraphy, petrology, and geochemistry, Parinacota sector collapse, Old Cone - Young Cone Lago Chungará, and views, Parinacota colonial village, distal Parinacota debris avalanche deposit, secondary mud flows.

Day 8 (05-Oct)

Parinacota petrology, lava flows and domes, maximum elevation during the day 4860 m above sea level, involves 4WD shuttle / walking, total ca. 10 km between 4800 and 4600 masl.

Day 9 (06-Oct)

Return from Putre to Arica : Valley incision history, post-erosional ignimbrites decending from the Altiplano to the Pacific; evening welfare-dinner at restaurant “Maracuyá”; lodging at Hotel Amaru.

Day 10 (07-Oct)

Leave Arica

Optional: Guided hike through Azapa valley: Ignimbrites, erosion and sedimentation processes, tectonics, valley incision history * minor transportation costs will be paid separately.