China's Mengxiang Drillship Retrieves Deep-Sea Basalt in South China Sea

China's scientific ocean drilling vessel Mengxiang has successfully retrieved oceanic basin basalt core samples from a water depth of 4,100 meters in the South China Sea, according to state media reports. Over a 30-day mission, the vessel completed drilling and coring across two wells, reaching a maximum completed drilling depth of 4,929.17 meters and penetrating 864.77 meters into the seabed. The mission recovered 4.27 meters of basalt core using domestically developed rotary coring tools, making China the third country—after the United States and Japan—to retrieve deep-ocean basin hard-rock samples using a scientific drillship.

The successful recovery of oceanic basin basalt confirms China's operational capability for scientific deep-water drilling down to the 5,000-meter class. By demonstrating domestic rotary coring equipment in hard basaltic rock, the expedition breaks a historical technical duopoly previously held by the United States and Japan in drillship-based deep-sea hard-rock retrieval, providing critical geological material to study continental margin rifting and tectonic evolution.

China’s newly commissioned ocean drilling vessel, the Mengxiang, has completed a 30-day trial drilling mission in the South China Sea, recovering basalt core samples from an oceanic basin at a water depth of 4,100 meters, according to reports by China News Service and People's Daily. The operation elevates China’s deep-sea scientific drilling and coring capability to the 5,000-meter class, making it the third country after the United States and Japan to retrieve hard-rock samples from a deep-ocean basin using a drilling vessel. Organized by the China Geological Survey under the Ministry of Natural Resources and executed by the Guangzhou Marine Geological Survey, the expedition encompassed 170 scientific personnel drawn from nine domestic organizations, including China Oilfield Services Limited (COSL), China State Shipbuilding Corporation (CSSC), Peking University, China University of Geosciences (Wuhan), Hainan University, and Hainan Tropical Ocean University. The vessel has since returned to its home port in Guangzhou. During the voyage, the Mengxiang executed drilling and coring operations across two separate wells. Official figures released by the Ministry of Natural Resources indicate that the vessel achieved a maximum completed drilling depth of 4,929.17 meters, with a maximum subsurface penetration footage of 864.77 meters. These figures set a new national record for operational water depth during an independently executed drilling campaign. A key milestone of the mission was the deployment of domestically engineered rotary coring tools, which successfully extracted 4.27 meters of basalt core from the oceanic basement. Penetrating hard crystalline igneous rock beneath thousands of meters of water presents significant engineering hurdles, requiring high dynamic positioning stability and robust mechanical cutting assemblies capable of enduring extreme pressures. Chinese authorities stated that the trial verified the country's full-process operational capabilities in ultra-deepwater scientific ocean drilling, spanning hardware reliability, coring system performance, and technical workflows. The acquired basalt samples are slated for laboratory analysis to investigate the regional tectonic evolution and geodynamic history of the South China Sea basin.