Permian in age. In the north of China coal is from the Jurassic in the west but reaches the Cretaceous in parts of the northeast. Tibet and Qinghai have a relative dearth of coal measures. China's petroleum reserves are located off or near the eastern seaboard and in the Taklamakan Desert. Unproven oil reserves in the South China Sea are part of the motivation for the continued border disputes in the region. Oil shale reserves have also been discovered in the north of the country. History of Chinese geology Ancient Geological topics are discussed in some of China's earliest writings. Between 500 BC and 800 AD Chinese scholars described mountains, minerals, fossils and documented the locations of ore bodies. They also noted that some of these marine fossils came from the tops of mountains. Fossils and some minerals were prized for there aesthetics and medical properties. One practice involved dissolving a fossil (calcite) in vinegar (an acid) and then drinking the liquid. However, as knowledge of the natural world was excluded from the imperial examination system no systematic study developed. It was also observed in the 11th century, by Chinese scholar Shen Kuo, in his work Dream Pool Essays, that the existence of fossils of species that no longer lived in the area, showed that climates had changed in the past. He also inferred that the landscape evolved over time, due to erosion and uplift. This led him to believe that vast spans of time were needed to form China's geomorphology. Scientific era It was not until late in the Qing dynasty (1644–1911) that the government formulated a policy to introduce foreign science and technology into China. Modern geologic ideas were introduced with the establishment of technical schools and the translation into Chinese of works by James D. Dana and Charles Lyell during the 1870s. Early in the twentieth century, foreign geology teachers were brought to China and Chinese students were sent to foreign countries to study geology. This infusion successfully developed the modern teaching and practice of geology in China. In the 2000s the discovery of a number of novel dinosaur fossils has led to international interest in Chinese paleontology. China also has international significant fossil beds from the Precambrian (Weng’an Biota), the early Cambrian (Chengjiang Biota) and the Early Cretaceous (Jehol Biota). Chinese fossils have provided the missing link in many evolutionary trees. China has also been the