by Zhiqin Xu

This proposal seeks funding for a drilling program in Ultrahigh-Pressure Rocks as part of the Chinese Continental Scientific Drilling, CCSD. The Su-Lu - Dabie UHP Belt in eastern China is the Worlds most prominent exposure of previously very deeply subducted and highly metamorphosed rocks. After detailed site investigations in three areas suitable for deep drilling a location was choosen during an ICDP cosponsored workshop in August 1997. In the Donghai area in the southwesternmost part of the belt a high-velocity layer at 3 to 4 km depth, frequently existing mining boreholes and considerable infrastructure favour drilling. A 1 to 2 km pilot hole and a 5 km main hole are planned within a program of deep geological and geophysical investigations, drilling, coring and related experiments as well as long-term monitoring.

• Major scientific issues are: · Studying the deep roots of crust-mantle intereaction at a convergent plate boundary, · Formation and uplift of UHPM rocks, · Systematic collection of data on the deepest known orogenic root, · Studying post-orogenic processes such as exhumation rate, cooling history, partial melting and magmatic activity, · UHPM ore deposits; such as rutile which is bound to eclogite and · earthquake prediction at the nearby Tanlu Fault.

CCSDP, Convergent Margins, Dabie-Sulu, DONGHAI, Drilling, ICDP-1998/09, P.r. China, UHPM Belt

Latitude: 34.5, Longitude: 118.783