Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan‐Tibetan orogen

Plane strain, thermal‐mechanical numerical models are used to examine the development of midcrustal channel flows in large hot orogens. In the models, radioactive self‐heating reduces the viscosity of tectonically thickened crust and increases its susceptibility to large‐scale horizontal flow. Channels can be exhumed and exposed by denudation focused on the high‐relief transition between plateau and foreland. We interpret the Himalaya to have evolved in this manner. Channel flows are poorly developed if the channel has a ductile rheology based on wet quartz flow laws, and well developed if there is an additional reduction in viscosity to 10 19 Pa s. This reduction occurs from 700°C to 750°C in the models and…

• CI
  Canadian Institute for Advanced Research
• CR
  Canada Research Chairs