Re-evaluating the geochronology of the Permian Tarim magmatic province: implications for temporal evolution of magmatism

Abstract

Abstract:The Permian Tarim magmatic province has 118 published ages, ranging from 358 to 205 Ma, but the timing of mafic magmatism is not well constrained. We report two new secondary ion mass spectrometry U-Pb zircon dates on the Halahatang trachydacite and Wajilitag olivine clinopyroxenite, which are 287.2 ± 2.0 Ma and 283.2 ± 2.0 Ma, respectively. The trachydacite overlies the uppermost basalt and constrains the latest eruption age of basalt in northern Tarim. The latter is the first high-resolution date for the Wajilitag mafic layered intrusion. By screening all published ages, we identified 22 robust ages, ranging from 290.9 ± 4.1 to 261.7 ± 1.8 Ma. The robust ages together with our new data reveal a protracted period of mafic magmatism at c. 283 and c. 267 Ma. Silicic magmatism occurred from 291 to 272 Ma. Although the current known volume of Tarim basalt is too small to qualify as a large igneous province, the eroded and intrusive components, as well as pyroclastic deposits and silicic lavas, may increase the estimated volume. Further work is required to refine the duration of magmatism and the volume estimate of the province.Supplementary material: A list of all the published dates, raw data of published 40 Ar-39 Ar dates, raw data of published U-Pb dates, published geochemistry data used for calculation and complete details of the data evaluation are available at

Zircon U–Pb ages and Hf–O isotopic signatures of the Wajilitag and Puchang Fe–Ti oxide–bearing intrusive complexes: Constraints on their source characteristics and temporal–spatial evolution of the Tarim large igneous province

“…292 to 287 Ma. This is consistent with strong field evidence that the rhyolitic lavas are intercalated with basaltic lavas, showing that the extrusive felsic rocks and their surrounding flood basalts could be essentially coeval(Shangguan et al, 2016; Tian et al, 2010). As stated above, seismic and deep borehole data along with outcrops indicated that the spatial the magmatic pulse is widespread, probably covering the entire TLIP(Fig.…”

“…Importantly, although most previous studies suggested that the TLIP could been attributed to a mantle plume, currently age data on the TLIP revealed a relatively long time interval (up to 45 Myr) of the early Permian magmatism (Li et al, 2011;Shangguan et al, 2016;Wei et al, 2014;Xu et al, 2014 and references therein), as opposed to the short duration (1-5 Myr) of some classic plume head-generated LIPs, such as Deccan Traps, Karoo and Emeishan…”

“…In general, magmatism of silicic LIPs lasts longer than mafic LIPs (Bryan and Ernst, 2008;Ivanov et al, 2013). The TLIP contains both mafic and felsic composition, and thus falls between mafic and felsic end members (Shangguan et al, 2016).…”

Carbonatites of Tarim (NW China): First evidence of crustal contribution in carbonatites from a large igneous province

“…Intrusions of ultramafic and mafic rocks in the Wajilitage area and elsewhere span from 284 to 273 Ma in age, indicating a long-lived melt source (Zou et al 2015). According to our data and published work (Cheng et al, 2015;Shangguan et al, 2016), the Tarim carbonatites and other undersaturated alkaline rocks are perceptibly younger (by ~10-20 Ma) than this main stage of plume activity. Campbell and Griffiths (1990) proposed that plume magmatism lasts a relatively short time, with the bulk of magmas emplaced within 2-3 Ma and then followed by smaller-volume mantle melting products over a further 5-10 Ma.…”

“…These data place the carbonatites in the second (Guadalupian) pulse of magmatic activity, postdating the main extrusive events and the emplacement of ultramafic-mafic intrusions at Wajilitage, Puchang and elsewhere in the Tarim Block ( Fig. 3; Shangguan et al, 2016).…”