We present noble gas concentrations and helium isotope ratios measured in the pore fluids of two deep-sea sediment cores taken at the Azores Plateau. NeXe concentrations were used to estimate the atmospheric noble gas component within the pore fluids and to then determine the terrigenic helium component. The concentrations of terrigenic ³He indicate the presence of hydrothermal fluids and a mantle He component within the sediment pore space. At both sampling locations, the concentration of terrigenic helium increases with sediment depth. The observed concentration gradients suggest a diffusive transport of He through the sediments. The helium isotope ratio of the source of the terrigenic helium is characterized by a typical mid-ocean ridge basalt (MORB). These results support previous studies suggesting that the pelagic sediments surrounding the Azores host active hydrothermal systems.

Our data indicate that the transport of terrigenic helium takes place diffusively over larger areas of the ocean floor, and that the concentration of terrigenic helium in the pelagic sediments increases towards the Mid-Atlantic Ridge and Terceira Rift.

The data further suggests that in the Azores region the terrigenic noble gas component is only detectable in the sediment pore fluids and cannot be observed in the overlying bottom water. This highlights the potential of measuring noble gas concentrations and isotope ratios in the sediment column to identify hydrothermal activity in the ocean.

我们展示了在亚速尔高原采集的两个深海沉积物岩心的孔隙流体中测量的惰性气体浓度和氦同位素比率。Ne Xe 浓度用于估计孔隙流体中的大气惰性气体成分，然后确定陆源氦成分。^{terrigenic 3}的浓度He 表明在沉积物孔隙空间中存在热液流体和地幔 He 组分。在两个采样点，陆源氦的浓度随着沉积物深度的增加而增加。观察到的浓度梯度表明 He 通过沉积物扩散传输。陆源氦源的氦同位素比以典型的大洋中脊玄武岩（MORB）为特征。这些结果支持先前的研究表明亚速尔群岛周围的远洋沉积物拥有活跃的热液系统。

我们的数据表明，陆源氦的迁移发生在更大的海底区域，并且远洋沉积物中陆源氦的浓度向大西洋中脊和特塞拉裂谷的方向增加。

数据进一步表明，在亚速尔群岛地区，陆源惰性气体成分仅在沉积物孔隙流体中可检测到，而在上覆的底水中无法观察到。这突出了测量沉积物柱中的惰性气体浓度和同位素比率以识别海洋中的热液活动的潜力。