Based on paleomagnetic measurements and morphostratigraphy of red bed/clay sequences from pediments of the Liupan Shan and the Longdong Basin, the following results are revealed. The red bed/clay sediments became to accumulate at around 8.1 MaBP, which implied that the plantation surface developed since Late Cretaceous was broken by active fault, and its development was terminated. The Liupan Shan began to slightly uplift. The Liupan Shan experienced a small-scale uplift around 5.2 MaBP, inferred from the appearance of fine gravel sediments at that time. Consequently, a pediment was developed. The Liupan Shan accelerated uplift since about 3.8 MaBP at a large scale, which caused the deep incision of the rivers and the termination of fluvial and lacustrine deposition. Meanwhile, typical eolian red clay appeared since then. This uplift process is well correlated and in response to that of the Tibetan Plateau and the mountains around it.
<正>Objective Climate fluctuations over suborbital or millennial timescale display significant instability during the last glacial period,which are often superimposed upon the orbital periodicity.They triggered some abrupt climate events,such as the Dansgarrd/Oeschger(D-O)events recorded in the Greenland ice cores and the Heinrich(H) 相似文献
Rock magnetism research on eolian deposits from the Chinese Loess Plateau shows that magnetite, maghe- mite and hematite are the main magnetic minerals in loess-paleosol sequences and red clay se-quences[1―8], and finds that the magnetic susceptibility increase is positively correlated to the content of ultra-fine minerals and relatively strong pedogene- sis[7―15]. This offers significant information in studying the Late Cenozoic paleoclimatic history of Chinese Loess Plateau[1,5―8,10―22… 相似文献