Active denudation morphostructures from SAR ERS-1 images (SW Irian Jaya)
The geometry of active denudation, commonly observed in old mountain belts, is described for the the first time in an active setting using remote sensing imagery supported by field data.We favouredthe use of Synthetic Aperture Radar (SAR) European Remote Sensing satellite (ERS-1) images assisted by complementary remote sensing devices (Landsat TM), to analyse small effects of recent deformation. SAR ERS-1 images are sensitive to minute textural or topographic contrasts in an area where extremely dense vegetation earlier caused difficulties in remote sensing studies. We show that the southern flank of the western Fold-and-Thrust Belt of New Guinea in Irian Jaya is the site of an incipient and active tectonic denudation on the southern leading edge of a very recent (Pliocene-Pleistocene) orogen. The morphology described here is the result of polyphased neotectonics developed in three stages. The Pliocene collision was followed by a strike-slip environment that isolated the front of the belt, and by the currently active gravitational denudation.