Thursday, October 16, 2014

Bigger picture

A quick view at the regional context. The image captures most of Indonesia, Borneo, southern Malaysia, Australia, and Papua New Guinea.  In the center of the map is of field area, the islands surrounding the Savu Sea geographically referred to as Nusa Tengarra Timor, a province of Indonesia.  Timor Island, our current location, is composed of West Timor, Indonesia and the independent country of East Timor.

Pay close attention to the ocean bathymetry, especially in the Indian Ocean (bottom left corner) and the transition to the shallow sea that is north of Australia.  This step in ocean depth directly captures a major goal of our research - it represents the presence of dense oceanic lithosphere in the west versus the relatively buoyant continental lithosphere in the east.  The entire swath of lithosphere is moving northward towards Indonesia, then subducts below all of the southern portion of the country.  
In the western part of our study area, the Indian Ocean lithosphere descends into the Earth in a normal manner, producing a fairly typical subduction zone that gives rise to famous volcanoes throughout Java and Flores Islands.  In the west, the continental lithosphere (a northern extension of Australia) is colliding into SE Indonesia, producing what amounts to a spectacular geologic bulldozing.  We seek to analyze this spectacular configuration through combining research in seismology, geochemistry, geomorphology, geodynamics, and structural geology... it will truly be a challenging effort, but rewarding in the end.  
Often, when geologists research old tectonic environments where rocks of different age and origin are juxtaposed, they refer to the complex configuration of eastern Indonesia to illustrate their interpretation.  Even the most open minded of geoscientists may find it hard to accept that this region is composed of such a entangled web of microterranes and plate boundaries.  As such, we much continue to pursue understanding of the region, and so we move onwards...

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