The parallel Halmahera and Sangihe arcs in eastern Indonesia are sites of active arc-arc collision of considerable interest in developing understanding of the geodynamics and geochemistry of subduction zones. Owing to the comparative remoteness of the region, few ground-based studies of the volcanoes have been undertaken. Here, we report and integrate gas measurements and (isotope) geochemical analyses of lava samples for Dukono, Ibu, Gamkonora, Gamalama, and Makian volcanoes of the Halmahera arc. Summing gas fluxes for all five volcanoes indicates arc-scale emission budgets for H₂O, CO₂, SO₂, H₂S, and H₂ of 96,300 ± 27,000, 2093 ± 450, 944 ± 400, 79 ± 20, and 15 ± 4 Mg/d, respectively. Dukono is the greatest source of SO₂ and H₂, while Ibu emits the most H₂O and H₂S. Both Gamalama and Ibu are significant CO₂ sources. Dukono (farthest from the trench) releases the most CO₂-poor gas. Geochemical and isotopic analyses of recent ejecta emphasize the role of high fluid fluxes in the mantle wedge, necessary for partial melting of depleted mantle. Pb, Nd, and Sr isotope ratios, combined with Ba/Nd, Zr/Nd, Ba/Th, and Zr/Nb ratios, provide evidence for compositional variability along the Halmahera arc, and indicate decreasing subducted sediment contribution from south (Makian, Gamalama) to north (Gamkonora, Ibu, Dukono). Additionally, fluids formed by dehydration of altered crust become prominent at the northern volcanoes. Isotopic and Ba/Nb ratios from the Neogene and Quaternary sources compared to the current magmas further emphasize the evolution of magma genesis since the Neogene.

印度尼西亚东部平行的 Halmahera 弧和 Sangihe 弧是活跃的弧-弧碰撞的地点，对于加深对俯冲带的地球动力学和地球化学的理解具有相当大的兴趣。由于该地区相对偏远，很少对火山进行地面研究。在这里，我们报告并整合了哈马黑拉弧的 Dukono、Ibu、Gamkonora、Gamalama 和 Makian 火山熔岩样本的气体测量和（同位素）地球化学分析。对所有五座火山的气体通量求和表明 H ₂ O、CO ₂、SO ₂、H ₂ S 和 H _{2 的}弧尺度排放预算分别为 96,300 ± 27,000、2093 ± 450、944 ± 400、79 ± 20 和 15 ± 4 Mg/d。Dukono 是 SO ₂和 H ₂的最大来源，而 Ibu 排放的 H ₂ O 和 H ₂ S 最多。Gamalama 和 Ibu 都是重要的 CO ₂来源。Dukono（离海沟最远）释放的 CO ₂最多-贫气。最近喷射物的地球化学和同位素分析强调了高流体通量在地幔楔中的作用，这是耗尽地幔部分熔化所必需的。Pb、Nd 和 Sr 同位素比值，结合 Ba/Nd、Zr/Nd、Ba/Th 和 Zr/Nb 比值，为沿哈马黑拉弧的成分变异提供了证据，并表明从南部（马基安， Gamalama）向北（Gamkonora、Ibu、Dukono）。此外，蚀变地壳脱水形成的流体在北部火山中变得突出。与当前岩浆相比，新近纪和第四纪来源的同位素和 Ba/Nb 比值进一步强调了自新近纪以来岩浆成因的演化。