Cenozoic Uplift of the Central Yunnan Fragment, Southwestern China, Revealed by Apatite (U-Th)/He Dating
- PDF / 8,928,945 Bytes
- 8 Pages / 595.22 x 842 pts (A4) Page_size
- 29 Downloads / 192 Views
IS SSN 1674-487X X
Cenozooic Uplifft of thee Centrral Yunn C nan Fraagmentt, South hwesterrn China, Reveealed by y Apatitte (U-Th h)/He Dating D Ke Wu , Youpu Doong
*, Jiaxiin Duan, Xin n Ru, Dongyu ue Zhang, D Dan Wang
Facuulty of Land Reesource Engineeering, Kunmingg University of Science S and Technology, Kunm ming 650093, China C Ke Wu: https://orcid.org/0000-0003-4915-242X; Youpu u Dong: https:///orcid.org/00000-0002-2829-75 585 AB BSTRACT: Th he age of centrral Yunnan fraagment uplift has h long been debated, d with eestimates rang ging froom the Late Eocene to aboutt 1 Ma. To dettermine the cen ntral Yunnan fragment upliift time in the CeC noozoic, apatite (U U-Th)/He (AH He) was used to analyze the lo ow-temperaturre thermochron nology of samp ples froom the Jiaozi Mountain M areaa of the eastern n central Yunn nan fragment. The sampling area is located d in thee Dongchuan District D of Kun nming, Yunnan n Province, neear the Xiaojiaang fault zone. The results sh how thaat AHe ages from f the easteern part of cen ntral Yunnan fragment werre mainly conccentrated arou und 25.7–37.9 Ma, and a intensive uplift had happened h befo ore 36.5 Ma. Together witth previous lo owtem mperature thermochronologgy research on the western an nd eastern cen ntral Yunnan ffragment, we conc clu uded that the Yunnan Y Plateaau uplifted prior to 36.5 Ma,, in a west to east e sequence. T The uplift caused a change c in paleeo-geographicaal terrain, whicch may have altered a the anccient river systems of the sou utheast Tibetan Platteau. KE EY WORDS: central c Yunnan n fragment, (U U-Th)/He datin ng, uplift, Cenoozoic. 0
INTRODU UCTION Since thee Early Cenozoiic, the collisionn of Indo-Asian continents has ledd to the shortening of the Tibbetan Plateau crust. c The Qiangtangg terrane in the middle of the Tibetan Plateauu had risen to its currrent height beffore 40 Ma (Waang C S et al., 2008), 2 and as the Inndian-Asian coontinental collission continuedd, the plateau gradually expanded towards the north and the south, respectively. The T southern edge e of the Qinnghai-Tibet Plaateau had risen to itts present heighhts in the Mid--Miocene (Zhanng et al., 2018; Roowley et al., 2001), 2 while the t Hoh Xil Basin B reached its preesent height in the Late Pleisttocene (DeCellles et al., 2007). Thee northeastern part of the Tibbetan Plateau grradually uplifted in the Pliocenne and Quaterrnary, formingg the present Tibetaan Plateau witth Qilian Mounntains uplift inn the Late Cenozoicc (Tapponnier et e al., 2001). The southeastern margiin of the Tibettan Plateau hass distinct geomorphhological featurres with a graduual and slow looss of altitude from northwest to southeast, beaaring no signifficant geomorphologgical differencees (Fig. 1). Twoo main deform mation modes have been b proposed to explain thhe formation of the southeast marrgin of the Tibbetan Plateau: the t first is thaat the IndoChina terrrane and the Sichuan-Yunnann fragment extrruded to the southeaast along a largge strike-slip faault with large-scale clockwise rotaation (
Data Loading...
