Experimental study on dehydration of pelite by high-pressure differential thermal analysis
泥质岩脱水作用的高压差热实验研究

Metamorphic dehydration in subduction zones plays a significant role in the genesis of slab-derived fluids and the generation and evolution of arc magmas. Because pelite is the typical representation of sediments within the upmost part of subducted slabs, it has been chosen as the starting materials for the experimental studies on the dehydration temperatures under high pressures from 1.5 to 4. 0GPa by high-pressure differential thermal analysis (HP-DTA). The result shows that the dehydration temperatures have a closely negative linear correlation with the corresponding pressures. The comparison between this result and the general geothermal gradients in subduction zones worldwide suggests that the depth at which the metamorphic dehydration of pelite occur in subduction zones varies mostly in the range from 75 to 145km, which provides further experimental evidence for the location of arc magma origin.