Dataset for: A huge mantle reservoir for subducted carbon beneath Central-East Asia

This dataset originates from the article “A huge mantle reservoir for subducted carbon beneath Central‑East Asia.” Mg‑Zn‑Sr‑Nd‑Hf‑Pb isotopic and major‑trace element data from Russian Cenozoic basalts reveal mantle metasomatism by slab‑derived melts/fluids, providing key evidence for deep carbon recycling and slab–mantle/crust–mantle interactions in Central‑East Asia. Detailed geochemical analyses were conducted on well‑correlated late Cenozoic volcanic systems in southeastern Siberia—Oka, Vitim, Udokan, and Tok. The samples exhibit SiO₂ (41.2–52.0 wt.%), total alkali (Na₂O+K₂O, 3.8–7.9 wt.%), Al₂O₃ (11.2–16.0 wt.%), MgO (6.6–12.0 wt.%), and TiO₂ (1.6–3.2 wt.%) contents similar to low‑silica basaltic melts in East Asia. They are enriched in light rare earth and large‑ion lithophile elements, depleted in heavy rare earths, with (La/Yb)ₙ = 8.78–31.0, resembling ocean‑island basalts. Radiogenic isotopes vary as (⁸⁷Sr/⁸⁶Sr)i = 0.703577–0.705135 and εNd(t) = +4.93 to –2.24, indicating the mantle source with multiple components. Magnesium isotopes show δ²⁶Mg values of –0.25±0.03‰ to –0.43±0.03‰, lower than peridotitic mantle and mid‑ocean ridge basalts (MORBs). Zinc isotopes show δ⁶⁶Zn values of +0.30±0.010‰ to +0.44±0.02‰, higher than normal mantle and MORBs. This coupled light‑Mg–heavy‑Zn signature points to the presence of carbonate in the melts (carbonate minerals can have δ²⁶Mg as low as –5.57‰ and δ⁶⁶Zn up to +1.67‰). Subducted slabs can deliver substantial carbon carriers (marine sediments, altered oceanic crust) into the deep mantle; melting of these slabs at depth generates low‑silica, carbonate‑bearing melts, offering a novel perspective on the origin of Russian Cenozoic basalts.本数据集源自论文《中亚-东亚下方俯冲碳的巨型幔源储库》。来自俄罗斯新生代玄武岩的镁（Mg）、锌（Zn）、锶（Sr）、钕（Nd）、铪（Hf）、铅（Pb）同位素及主量-微量元素数据，揭示了板片来源熔体/流体引发的地幔交代作用，为中亚-东亚地区的深部碳循环及板片-地幔/地壳-地幔相互作用提供了关键证据。研究团队对西伯利亚东南部关联性极佳的晚新生代火山系统——奥卡（Oka）、维季姆（Vitim）、乌多坎（Udokan）与托克（Tok）开展了详尽的地球化学分析。 样品的二氧化硅（SiO₂）含量为41.2~52.0 wt.%，总碱量（Na₂O+K₂O）为3.8~7.9 wt.%，三氧化二铝（Al₂O₃）为11.2~16.0 wt.%，氧化镁（MgO）为6.6~12.0 wt.%，二氧化钛（TiO₂）为1.6~3.2 wt.%，与东亚地区的低硅玄武质熔体特征相似。样品富集轻稀土元素与大离子亲石元素，亏损重稀土元素，球粒陨石标准化的镧/镱比值[(La/Yb)ₙ]为8.78~31.0，与洋岛玄武岩类似。其放射成因同位素组成表现为初始锶比值(⁸⁷Sr/⁸⁶Sr)i=0.703577~0.705135，t时刻钕同位素异常值εNd(t)为+4.93至-2.24，指示地幔源区具有多端元组分特征。 镁同位素的δ²⁶Mg值为-0.25±0.03‰至-0.43±0.03‰，低于橄榄岩型地幔与洋中脊玄武岩（MORBs，mid-ocean ridge basalts）；锌同位素的δ⁶⁶Zn值为+0.30±0.010‰至+0.44±0.02‰，高于正常地幔与洋中脊玄武岩。这种轻镁-重锌的耦合同位素特征，表明熔体中存在碳酸盐矿物（碳酸盐矿物的δ²⁶Mg可低至-5.57‰，δ⁶⁶Zn最高可达+1.67‰）。俯冲板片可将大量碳载体（海洋沉积物、蚀变洋壳）带入深部地幔；板片在深部熔融可形成低硅含碳酸盐熔体，这为俄罗斯新生代玄武岩的成因提供了全新视角。