Tarim Basin

The Tarim Basin is a massive endorheic basin located in the Xinjiang region of northwestern China.

An endorheic basin is a land area where rivers do not reach the ocean. Instead, they flow into inland lakes or disappear into the ground. This basin covers approximately 888,000 square kilometers. It is one of the largest basins in northwest China. The region is often called Altishahr, which means "six cities" in the Uyghur language.

Historically, the basin was distinct from Dzungaria to the north. These two areas were governed separately until they were merged into Xinjiang province in 1884.

The geography of the basin is defined by high mountain boundaries. The Tian Shan mountain range forms the northern border. To the south, the Kunlun Mountains sit on the edge of the Tibetan Plateau. Between these mountains lies the Taklamakan Desert, which dominates much of the landscape.

Because the desert is so dry, it is too harsh for permanent human habitation. Most people live in oases near rivers. These rivers carry water from the melting snow and glaciers of the surrounding mountains. This water feeds the life of the basin but never reaches the sea.

Water movement in the basin follows a complex sequence. Snow on the Karakoram mountain range melts into glaciers. These glaciers move down valleys and create rivers. The Yarkand, Kashgar, and Aksu rivers join to form the Tarim River. This river flows along the northern side of the basin. In the past, the Tarim River flowed toward the ancient site of Loulan. However, around 330 AD, the river changed its course toward the southeast near Korla. Today, the river ends at Lop Nur, which is a saline, marshy depression.

Human history in the basin is tied to these water sources and trade routes. The Tarim Basin was a vital part of the Silk Road. Traders used three main oasis-dependent routes to navigate the area. One route ran along the northern edge of the Taklamakan Desert. Another route followed the southern edge, passing through places like Khotan. A third, shorter route connected the north and south through the Lop Nur region.

This middle route was abandoned after the 4th century as the area became uninhabitable. Ancient cultures, such as the Xintala culture around 1700 BC, used mud bricks to build small settlements.

Transportation has evolved from ancient caravans to modern engineering. In the past, travelers used mountain passes to move between regions. For example, the Iron Gate Pass allowed travel toward the north. Today, the basin is surrounded by a large railway loop. This includes the Southern Xinjiang Railway and the Hotan–Ruoqiang railway.

Major roads like Highway 315 and the Tarim Desert Highway also cross the region. The Tarim Desert Highway is a significant engineering achievement that connects Niya to Luntai. These modern systems allow people to move through the desert much more easily than ancient traders.

The basin is also a major site for natural resources and energy. The ground contains large reserves of petroleum and natural gas. Methane makes up more than 70 percent of the natural gas reserves. Researchers have also found a vast, carbon-rich underground sea beneath the basin.

Beyond fossil fuels, the region is important for renewable energy. The Taklamakan Desert provides vast areas for solar and wind power development. A high-voltage power loop has been built around the basin. This system collects energy and transmits it to other parts of China.

Geologically, the basin formed through a process of continental growth. During the Carboniferous to Permian periods, an ancient microcontinent joined the larger Eurasian continent. This process ended during the early Triassic when the Palaeo-Asian Ocean closed. Today, the crust of the basin is being pushed under the Tian Shan and Kunlun mountains. This movement causes deformation at the edges of the basin. The center of the basin contains thick layers of sedimentary rocks. Some of these layers are more than 15 kilometers thick.