Crustal Radioactivity and Motion as Causes of Regional Metamorphism in the Damara Orogen

Regional metamorphism in the Damara Orogen shows a marked contrast in pressure and temperature conditions between the Central Zone and the southern orogen. This is attributed to opposite vertical motion and to different radiogenic heat generation in these parts of the orogen, while mantle heat flow was supposedly uniform within the orogen and has remained normal during the thermal event. The concept of orogenic movements implies thermal effects of crustal shortening in the southern orogen and an additional heat advection due to intrusion of granites in the Central Zone.