Devonian–Carboniferous Pillow OIB-Type Basalts in the Youjiang Basin, SW China: Implications for the Eastern Extension of the Paleo-Tethys Branch Ocean
Jie Yang , Yuansheng Du , Hu Huang , Jianghai Yang , Hongwei Huang , Zhiqiang Huang
Journal of Earth Science ›› 2023, Vol. 34 ›› Issue (3) : 690 -705.
Devonian–Carboniferous Pillow OIB-Type Basalts in the Youjiang Basin, SW China: Implications for the Eastern Extension of the Paleo-Tethys Branch Ocean
Late Paleozoic pillow basalts are well preserved in the Youjiang Basin of SW China. In this study, we conducted geochemical and Sr−Nd isotopic study on the Late Devonian and Late Carboniferous basalts in Napo area, Youjiang Basin. The analyzed samples comprise moderate SiO2, TiO2, Mg#, and REE contents, with slightly positive or negative Eu anomalies, similar to the chemical nature of OIB (Oceanic island basalt). All basalts show low (143Nd/144Nd)i and (87Sr/86Sr)i values, close to EMI-type (I-type Enriched Mantle) magma source. Late Carboniferous basalts display higher (87Sr/86Sr)i, Nb/Th, and lower ε Nd(t), Zr/Nb values than those of the Late Devonian basalts, implying progressively decreased enrichment components in the magma source processes. Such evolution trend reflects a continuous lithospheric thinning event, supporting a progressive rifting setting of the Youjiang Basin along the southwestern margin of the Yangtze Block in Late Paleozoic. Combined with regional geological background, the Youjiang Basin is viewed as a continental rift basin related to the opening of the Paleo-Tethys Ocean in Late Devonian and became a passive continental margin basin in Carboniferous. The Paleo-Tethys branch ocean probably extended further to the southern Youjiang Basin, likely corresponding to the Song Ma suture zone.
basalts / Late Paleozoic / Paleo-Tethys ocean / Youjiang Basin / geochemistry
| [1] |
|
| [2] |
BGMRGP Regional Geology of Guizhou Province. Bureau of Geology and Mineral Resources of Guizhou Province, 1987, Beijing: Geological Publishing House, 1-704 (in Chinese) |
| [3] |
BGMRGR Regional Geology of Guangxi Zhuang Autonomous Region, 1985, Beijing: Geological Publishing House, 1-853 (in Chinese) |
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
| [39] |
|
| [40] |
|
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
|
| [46] |
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
| [51] |
|
| [52] |
|
| [53] |
|
| [54] |
|
| [55] |
|
| [56] |
|
| [57] |
|
| [58] |
|
| [59] |
|
| [60] |
|
| [61] |
|
| [62] |
|
| [63] |
|
| [64] |
|
| [65] |
|
| [66] |
|
| [67] |
Pearce, J., 1982. Trace Element Characteristics of Lavas from Destructive Plate Boundaries. In: Thorpe, R. S., ed., Andesites: Orogenic Andesites and Related Rocks. John Wiley and Sons. 252–548 |
| [68] |
Pearce, J., 1983. The Role of Sub-continental Lithosphere in Magma Genesis at Destructive Plate Margins. In: Hawkesworth, C. J., Norry, M. J., eds., Continental Basalts and Mantle Xenoliths. Nantwich Shiva. 230–249 |
| [69] |
|
| [70] |
|
| [71] |
|
| [72] |
|
| [73] |
|
| [74] |
|
| [75] |
|
| [76] |
|
| [77] |
|
| [78] |
|
| [79] |
|
| [80] |
|
| [81] |
|
| [82] |
|
| [83] |
|
| [84] |
|
| [85] |
|
| [86] |
|
| [87] |
|
| [88] |
|
| [89] |
|
| [90] |
|
| [91] |
|
| [92] |
|
| [93] |
|
| [94] |
|
| [95] |
|
| [96] |
|
| [97] |
|
| [98] |
|
| [99] |
|
| [100] |
|
| [101] |
|
| [102] |
|
| [103] |
|
| [104] |
|
| [105] |
|
| [106] |
|
| [107] |
|
| [108] |
|
| [109] |
|
| [110] |
|
| [111] |
|
| [112] |
|
| [113] |
|
| [114] |
|
/
| 〈 |
|
〉 |