Neotectonics of Arc-Continent Collission

Institute for Geophysics

A GSA Penrose Meeting

Neotectonics of Arc-Continent Collision
Manizales, Colombia
17-21 January, 2011

The objective of this conference is to bring together an international group of scientists to discuss the neotectonics and seismic hazards of shallow slab subduction in areas of arc-continent collisions. In particular, we invite participants interested in discussing various aspects of arc-continent collisions around the globe.

GSA Today announcement: See page 46 of Vol. 20, No. 9

Registration and Applications:
Deadlines:



http://bit.ly/9wzsr4




Conveners:
Paul Mann paulm@utig.ig.utexas.edu; Institute for Geophysics, Jackson School of Geosciences, University of Texas-Austin, 10100 Burnet Rd.-ROC 196, Austin, Tx. 78758, USA
Carlos Vargas Jimenez cavargasj@unal.edu.co; Departamento de Geociencias, Universidad Nacional de Colombia, Bogotá, Colombia
Caroline Whitehill carrie@utig.ig.utexas.edu; Institute for Geophysics, Jackson School of Geosciences, University of Texas-Austin, Austin, Tx., USA

Description and Objectives:
The objective of this conference is to bring together an international group of scientists to discuss the neotectonics and seismic hazards of shallow slab subduction in areas of arc-continent collisions. In particular, we invite participants interested in discussing various aspects of arc-continent collisions around the globe:

1. How do the plate tectonic settings and crustal structures of ongoing arc-continent collisions in different parts of the world (e.g., Taiwan, Papua New Guinea, Japan, Kamchatka, Italy, Alaska) control the pattern of surface deformation and the geometry of shallowly subducted slabs? Are plate driving forces the main control on the regional deformation patterns or do mantle forces acting on subducted or broken off slabs also play a role?
2. How does arc collision and shallow subduction generate anomalously broad crustal zones of deformation as seen in areas like the Andes of northwestern South America, Taiwan and Papua New Guinea? Are these broad zones of crustal deformation "thin-skinned" and deforming on shallow detachments with large amounts of shortening or "thick-skinned" and rooted on older fault surfaces and reactivated rifts?
3. The process of vertically detaching slabs or "slab breakoff" and torn slabs shown by areas of strong slab dip change is common to many areas of arc-continent collision and shallow subduction, yet the tectonic mechanisms and timing of this process are not well understood. How have recent advances in seismology, tomography and geodynamic modeling improved our understanding of slab subduction and breakoff and how do these breakoffs affect the pattern of observed earthquakes and slab-related volcanism?
4. Is coupling of the subducted slab and arc in arc-collision zones any greater than that observed along non-collisional subductoin boundaries and therefore linked to higher levels of larger and more destructive earthquakes? How can this improved level of academic understanding of arc collision and shallow subduction at all levels in the crust and upper mantle help improve maps of seismic hazard and communicated to the public living in broad plate boundary zones?

Central Colombia was chosen as the meeting venue because central Colombia is an excellent natural laboratory to study all aspects arc-continent collision and the neotectonics of shallow slab subduction. From the late Cretaceous to Miocene, accretion of arcs and oceanic plateaus has shaped the active margin. Since the middle Miocene (ca. 12 Ma), the Panama arc has been colliding with the continental margin of the northwestern South American plate and superimposed earlier tectonic events. This cumulative tectonic history has produced many features illustrative of the four study themes above: 1) formation of the widest area of the Andean mountain chain (500 km) over its entire of more than 8000-km length from Colombia to Tierra del Fuego; 2) shallow subduction of the Caribbean slab beneath the northern Andes with active slab tears defining distinct slabs seen with tomographic studies and "breakoff" occurring along the downdip edge of the slab; 3) large, historic earthquakes produced by strong coupling at the shallow subduction interface, and 4) thick Miocene-present sedimentary basins that provide a record of structural events.

Proposed Itinerary:
Day 1 - Mon., 17 January: Talks and posters with a focus on "Overview of Arc-Continent collision and active tectonics"
Day 2 - Tues. , 18 January: Field day in the Nevado del Ruiz volcanic complex
Day 3 - Weds. , 19 January: Talks and posters with a focus on shallow slab subduction and geohazards
Afternoon and evening breakout groups:
(1) Neotectonic framework
(2) Basinal response,
(3) Slab and far-field effects,
(4) Geohazards
Day 4 - Thurs. , 20 January: Field day in the Epicentral area of the Armenia Earthquake (Mw 6.2,25-01-1999) and visiting the Romeral Fault System
Day 5 - Fri., 21 January: Round table discussions and wrap up presentations

Registration and Logistics:
The registration fee will cover hotel lodging for five nights (16-21 January) and all meals during the conference dates. Airfare is not included in the registration fee. See the GSA website for registration fees.

Participants must arrive in Manizales no later than Sunday, January 16th and are responsible for their own travel arrangements to Manizales. We recommend booking your flight from abroad to Bogota to include a short 30 minute commuter flight from Bogota to Manizales 300 km west (~8 hr drive) of Bogota. We will provide ground transportation between the Manizales airport and the conference venue.





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