Chongqing -On April 22nd, marking the 54th Earth Day, tourists and geologists joined experts from the Chongqing Municipal Planning and Natural Resources Bureau in uncovering the city's geological secrets.

Chongqing's unique topography, characterized by its convergence of mountains and rivers, has long made it an attractive destination for visitors. Interestingly, ancient Chongqing was once a lake, with the Yangtze River flowing from east to west across the region. Nowadays, along the banks of the Jialing River, curious onlookers can marvel at million-year-old rock formations and remnants of "dinosaur bones."

The Jialing riverbank in Chongqing. (Photo/ Chongqing Municipal Planning and Natural Resources Bureau)

To many locals, the Jialing River is considered Chongqing's lifeblood. This is partly because the river converges with the Yangtze River, creating the long and narrow Yuzhong Peninsula, a well-known regional landmark.

"During the Jurassic period, Chongqing was a vast lake. The climate at the time was hot and dry, forming massive layers of red sandstone and mudstone through sedimentation. These thick layers form the bedrock of the Yuzhong Peninsula," explained Dong Meng, a senior engineer at the Chongqing Geological Mineral Exploration and Development Bureau. The formation of the Yuzhong Peninsula is intimately linked to the evolution of the Yangtze and Jialing Rivers.

The Jialing Riverbank offers visitors a chance to uncover the mysteries of Chongqing's geological evolution. Observers can spot layers of pebbles covering the sandstone and mudstone rock formations. The lower part of the rock was created during the Jurassic period, roughly 144 to 208 million years ago, while the pebble layer above dates back only a few thousand to 12,000 years.

Moreover, visitors can discover rocks resembling dinosaur bone fossils along the riverbank. These intriguing formations are sandstones that have undergone differential weathering and erosion by the river.

The resemble dinosaur bone fossils on the river beach. (Photo/ Chongqing Municipal Planning and Natural Resources Bureau)

In addition to the Jialing Riverbank, visitors can explore the historical significance of the Foutuguan trail, where many bomb shelters built during the Second World War still stand today. 

The Foutuguan monorail train station.

"The construction of the cliffside trail and the numerous air-raid shelters along the Fotuguan trail are closely related to the area's geological structure," stated Dong Meng.

Fotuguan features two distinct rock layers: purplish-red mudstone, which is relatively soft and easy to excavate, and hard, thick sandstone, which provides excellent stability. Both rock types were once submerged underwater.

A 300-meter-long walkway was constructed in the area to take advantage of sandstone's stability. The air-raid shelters' roofs are made of sandstone, known for its high hardness and resistance to collapse. This makes it an ideal protective covering for the shelters.