On July 28, Phase I of the Weihe Basin Deep Drilling Project officially commenced in Guanlu Town, Weinan City, Shaanxi Province. The project aims to unlock 66 million years of climate change history in East Asia through ultra-deep drilling reaching depths of up to 10,000 meters.

Located between China’s Loess Plateau and the Qinling Mountains, the Weihe Basin is regarded as a natural geological “chronicle,” preserving a complete record of Earth’s Cenozoic climate and environmental evolution.

Jointly initiated by Academician An Zhisheng of the Institute of Earth Environment, Chinese Academy of Sciences, and an international team of scientists, the project will retrieve ultra-deep core samples to systematically study the co-evolution of the lithosphere, hydrosphere, and biosphere. The goal is to reveal the mechanisms of East Asian climate and environmental change during the Cenozoic, while also assessing the potential of geothermal and helium resources, thereby supporting China's national deep-Earth strategy.

Academician An Zhisheng, chief scientist of the project, explained that the drilling site lies in a deeply sunken and tectonically stable area of the basin, ideal for preserving long-term climate records. The challenge lies in the depth and the requirement to retrieve core samples with over 95% integrity to ensure accurate reconstruction of historical climate variations—a significant feat for drilling down to 3,000 meters.

According to the plan, the project will be executed in two phases:

• The current Phase I targets the upper 3,000 meters of sedimentary layers, dating back about 10 million years, to reconstruct the hydroclimatic history of East Asia since the Late Miocene.

• Phase II will drill down to depths between 7,500 and 10,000 meters to evaluate the geothermal and helium resource potential.

Compared with oceanic drilling, the terrestrial sediment in the Weihe Basin offers higher-resolution climate records, making it a critical reference for understanding the ecological evolution of the Loess Plateau and forecasting future climate trends. The project is expected to fill a gap in global Cenozoic terrestrial climate records and contribute Chinese geological cores to global climate research.