Carboniferous-Permian magmatism in western section of the North Qaidam, northern Tibet Plateau: Response to the spatio-temporal evolution of the Paleo-Tethys Ocean

IF 7.2 1区地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Gondwana Research Pub Date : 2025-02-21 DOI:10.1016/j.gr.2025.02.007

Panlong Wang , Yongjun Li , Yujun Zhuang , Pingyang Gu , Gaoxue Yang , Fenghao Duan , Jianye Zhang , Wei Li , Nanhe Peng , Qian Wang , Hai Li

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引用次数: 0

Abstract

The origin of Late Paleozoic igneous rocks in the North Qaidam (NQ) remains controversial. This study presents comprehensive geochronological, geochemical, and isotopic data on the igneous rocks in western section of the NQ. The chronological results indicate that the Yanchangbeishan (YC) hornblende gabbro was formed at ca. 254 Ma; the Xiaosaishitengshan (XS) gabbro, biotite quartz-diorite, monzogranite, and andesite were formed at ca. 318 Ma, ca. 259 Ma, ca. 252 Ma, and ca. 271 Ma, respectively; and the Dasaishitengshan (DS) gabbro, tonalite, and biotite monzogranite were formed at ca. 268 Ma, ca. 272 Ma, and ca. 282 Ma, respectively. The Lu-Hf isotopic results show that the ε_Hf(t) values of YC hornblende gabbro, XS andesite, and DS gabbro and tonalite are + 1.21 to + 9.53, +9.01 to + 15.70, +0.05 to + 4.71, and − 5.43 to − 1.93, respectively. Among them, XS gabbro (high-alumina) and andesite, and YC gabbro (high-magnesium) exhibit significant depletions in Nb, Ta, and Ti, similar to island arc magmas, which formed by partial melting of depleted lithospheric mantle metasomatized by slab fluids to varying degrees. DS gabbro (high-Nb) shows slight depletions in Nb, Ta, and Ti, resembling intraplate rift basic rocks, and resulting from low-degree partial melting of depleted mantle wedge metasomatized by slab melts. XS biotite quartz-diorite, monzogranite, and DS biotite monzogranite have high SiO₂ (63.69–76.85 wt%) contents and low Mg^# values (28–43), classified as I-type granites, formed by partial melting of juvenile crust. DS tonalite (high Ba-Sr) shows depletions in Nb, Ta, and Ti, originating from the lithospheric mantle metasomatized by slab-derived fluids and undergoing extensive fractional crystallization. By integrating the results of this study with published work regarding the igneous rocks in the NQ, we propose a new tectonic evolution model involving Zongwulong Paleo-Tethys Ocean subduction slab roll-back and subduction zone retreat for the Late Paleozoic in the NQ.

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来源期刊

Gondwana Research 地学-地球科学综合

CiteScore

12.90

自引率

6.60%

发文量

298

审稿时长

65 days

期刊介绍： Gondwana Research (GR) is an International Journal aimed to promote high quality research publications on all topics related to solid Earth, particularly with reference to the origin and evolution of continents, continental assemblies and their resources. GR is an "all earth science" journal with no restrictions on geological time, terrane or theme and covers a wide spectrum of topics in geosciences such as geology, geomorphology, palaeontology, structure, petrology, geochemistry, stable isotopes, geochronology, economic geology, exploration geology, engineering geology, geophysics, and environmental geology among other themes, and provides an appropriate forum to integrate studies from different disciplines and different terrains. In addition to regular articles and thematic issues, the journal invites high profile state-of-the-art reviews on thrust area topics for its column, ''GR FOCUS''. Focus articles include short biographies and photographs of the authors. Short articles (within ten printed pages) for rapid publication reporting important discoveries or innovative models of global interest will be considered under the category ''GR LETTERS''.