Continental scientific drilling can be seen as "a telescope into the Earth's interior," since it offers insights into processes and pristine samples of rocks, fluids, and even the Earth's deep biosphere. As a founding member of the International Continental Scientific Drilling Program (ICDP), China has accomplished significant advancements in various research areas related to scientific drilling. The ICDP involvement garnered worldwide interest from researchers and established the Chinese Continental Scientific Drilling (CCSD) Project initiated in 2001, along with an increasing array of ambitious drilling initiatives in the nation.

　　The main hole of the CCSD Project located in Donghai county in the northern Ultra High Pressure (UHP) supracrustal zone in the Sulu Terrane, reached a depth of 5,158 meters. This area features eclogites and garnet peridotites occurring as lenses, pods, or layers within coesite-bearing gneisses, quartzite, mica schists, and amphibolites. The northern UHP granitic zone is a natural laboratory for investigating physical and chemical properties and geodynamic processes in a continental collision zone. This is because the structural relationship between the HP and UHP slices is well preserved there despite the post-collisional crustal extension and granitic intrusion.

　　The main hole demonstrates that significant volumes of crustal rocks from the South China Block have been subducted at least 120 km, followed by rapid uplift. Following the successful completion of the Donghai drilling, a number of continental scientific drilling initiatives have been undertaken, funded by the Chinese government and partly supported by the ICDP, resulting in a total drilling depth of over 35,000 meters.

　　As the deepest of more than 20 ICDP projects currently underway, the CCSD project has generated enormous amounts of data, as well as technical innovations in drilling and core recovery. Combined with borehole logging, geophysical experiments, field surveys and laboratory measurements, fresh core samples from the CCSD project provide a valuable resource for studying the structure, composition, deformation, physical properties and material cycling in a continental subduction zone. These results have made the Sulu Terrane a classic example for other continental collision zones such as the Himalayas and the Caledonides.