Geological Evolution

The Geopark's oldest tectonic movement is the Alxa movement, which took place during the end of the pre-Mesoproterozoic era, approximately 1.95 billion years ago. Throughout this era, various rock formations such as terrigenous clastic rock of marine facies, carbonate rock, and volcanic rock-flyschoid were formed in the early stages. During the later stages, the Geopark witnessed the development of marine volcanic rock-flysch formations. Following the Alxa movement, there was significant earth's crust uplift, which led to the transformation of the Geopark area into an ancient continent that divided the northern and southern sea regions. Sedimentary discontinuities emerged. This served as the foundation for the Meso-Neoproterozoic geological developments. Over time, several additional tectonic movements occurred. With the addition of Neotectonic movements, the present-day tectonic framework was ultimately established.

Dunhuang Basin

During the early Paleozoic era, diastrophism in the region was uneven. The northern part of the region experienced a decline in deposition, while the southern part continued to undergo denudation. However, during the Mesozoic era, crustal movements entered a new stable stage in contrast to the intense stage during the Paleozoic Era. The new stage was dominated by continental sedimentation. During this time, the seawater gradually receded starting from the late Triassic Period and never returned. The tectonic movement was not strong but rather frequent. The Indosinian movement and Yanshan movement further complicated the existing tectonic framework. In the Eocene epoch, certain areas experienced subsidence, which led to the formation of inland lake basins and the development of small Piedmont and intermountain depressions. The majority of stripped faults observed in these basin areas were synsedimentary in nature. Since the Quaternary period, the Geopark area has continuously undergone uplift and erosion. The prevalent landforms in the region primarily consist of the Gobi Plain and Piedmont proluvial fans, along with proluvial, moraine, and fluviolacustrine deposits.

Palaeogeographic Recovery Map of Cenozoic Dunhuang Basin

In the extensive span of geological history, diastrophism exhibits an imbalance across various stages. These distinct stages give rise to diverse types of geological actions, leading to varied outcomes. Consequently, within the Geopark, bountiful Geosites of different types are formed. The presence of yardangs, megadunes, wetlands, and lakes in the Dunhuang Basin exemplify the developmental processes of descending deposit and uplift erosion.