全市将统一建设专科医联体

百度 他前期的《唐代科举与文学》无疑是名作，晚年用力唐翰林学士生平考辨，是晚近唐代文史著作中最具意义和功力的著作之一。

YINCHUAN, July 29 (Xinhua) -- Under the scorching sun, Xu Xiaolong and his colleagues trudged through wild grass in the Gobi Desert, scanning the rocky foothills of Helan Mountain in Yinchuan, northwest China's Ningxia Hui Autonomous Region, in search of ancient carvings.

Upon finding a pattern on a rock, the team immediately photographed and recorded its location.

"This field survey not only assesses the preservation status of previously discovered rock carvings but also helps identify and document new ones," said Xu, 36, who works with the city's Helan Mountain rock art administration. He explained that the work would lay the groundwork for subsequent digital archiving and protection efforts.

Stretching 250 km, Helan Mountain is home to over 20,000 ancient rock carvings created by early inhabitants with stones, metal tools or mineral pigments. Dating back approximately 10,000 to 3,000 years, the carvings depict diverse subjects ranging from natural images like human faces, animals and handprints, to ancient life scenes such as herding, hunting and rituals.

Launched in 2020 as a follow-up to the 2000-2003 census, the administration has surveyed over 12 square km in and around the Helan Mountain rock art ruins park. The fieldwork is set to continue through the end of 2025.

TRACES OF ANCIENT LIVES

Among the carvings, one features two handprints -- one large and the other small. "The handprints likely signify 'me' and 'you,' carved onto the rock to seal an agreement," said Zhang Jianguo, deputy director of the administration.

He added that affixing a handprint to documents such as deeds and contracts was a traditional practice in China, and this rock carving reflects that enduring cultural continuity.

Within the park, the deepest carving reaches 1.5 cm, a depth that has survived millennia of weathering.

Via an experiment, the administration found that even three people carving throughout an entire day left only faint marks, indicating that prehistoric people likely spent multiple generations completing a single work.

"We assume that it was the tribal leaders or shamans who designed the patterns, and others might have carved and deepened the grooves in the following centuries as a way of expressing faith," he said.

Guided tours, cultural events and creative products have boosted public engagement, with the park drawing 900,000 visitors in 2024.

CONTINUOUS CONSERVATION

Despite their historic significance, the rock carvings face preservation challenges just like any other outdoor ancient rock art elsewhere in the world. Weathering has faded or erased many images, while freeze-thaw cycles caused by rainwater have led to cracking and peeling.

As part of efforts to strengthen the protection, China's State Council designated the site as a major national cultural heritage unit under protection in 1996, followed by the establishment of the administration in 2002. In 2003, the city-level Helan Mountain rock art protection regulation became China's first dedicated legislation for the preservation of rock art.

Zhang, who has witnessed and been involved throughout the entire conservation journey, recalled that concrete efforts included extensive field surveys, the construction of flood-prevention dams and protective fencing, as well as the development of protection plans to balance tourism with preservation.

In cooperation with other institutions, the administration reinforced 20 rock faces with carvings and cracks, injecting organic materials into fissures to prevent surface peeling from 2012 to 2017. A nanomaterial coating is sprayed onto surfaces for water- and sun-proofing protection and monitors have also been installed to collect humidity, temperature and wind data to guide future protection work.

"While the rock art may eventually fade, advancing technology allows us to employ all possible means to extend its legacy for as long as we can," Zhang said.