Chromite, a crucial high-conductivity mineral phase of peridotite in ophiolite suites, has a significant effect on the electrical structure of subduction zones. The electrical conductivities of sintered polycrystalline olivine containing various volume percents of chromite (0, 4, 7, 10, 13, 16, 18, 21, 23, 100 vol.%) were measured using a complex impedance spectroscopic technique in the frequency range of 10⁻¹–10⁶ Hz under the conditions of 1.0–3.0 GPa and 873–1223 K. The relationship between the conductivities of the chromite-bearing olivine aggregates and temperatures conformed to the Arrhenius equation. The positive effect of pressure on the conductivities of the olivine–chromite systems was much weaker than that of temperature. The chromite content had an important effect on the conductivities of the olivine–chromite systems, and the bulk conductivities increased with increasing volume fraction of chromite to a certain extent. The inclusion of 16 vol.% chromites dramatically enhanced the bulk conductivity, implying that the percolation threshold of interconnectivity of chromite in the olivine–chromite systems is ~16 vol.%. The fitted activation enthalpies for pure polycrystalline olivine, polycrystalline olivine with isolated chromite, polycrystalline olivine with interconnected chromites, and pure polycrystalline chromite were 1.25, 0.78–0.87, 0.48–0.54, and 0.47 eV, respectively. Based on the chemical compositions and activation enthalpies, small polaron conduction was proposed to be the dominant conduction mechanism for polycrystalline olivine with various chromite contents. Furthermore, the conductivities of polycrystalline olivine with interconnected chromite (10^–1.5–10^0.5 S/m) provides a reasonable explanation for the high conductivity anomalies in subduction-related tectonic environments.

铬铁矿是蛇绿岩组中橄榄岩中至关重要的高电导矿物相，它对俯冲带的电学结构具有重要影响。使用复阻抗光谱技术在以下频率范围内测量了包含不同体积百分比的亚铬酸盐（0、4、7、10、13、16、18、21、23、100 vol。％）的烧结多晶橄榄石的电导率10 ^-1 –10 ⁶ Hz在1.0–3.0 GPa和873–1223 K的条件下。含铬铁矿的橄榄石聚集体的电导率与温度之间的关系符合Arrhenius方程。压力对橄榄石-铬铁矿体系电导率的正作用远比温度弱。亚铬酸盐含量对橄榄石-亚铬酸盐体系的电导率有重要影响，其体积电导率随亚铬酸盐体积分数的增加而增加。包含16％（体积）的铬铁矿显着提高了整体电导率，这意味着在橄榄石-铬铁矿体系中，铬铁矿的互连互渗阈值为〜16％（体积）。拟合的活化焓为纯多晶橄榄石，多晶橄榄石与分离的亚铬酸盐，铬铁矿互连的多晶橄榄石和纯铬铁矿分别为1.25、0.78-0.87、0.48-0.54和0.47 eV。基于化学组成和活化焓，提出了小极化子传导是具有不同亚铬酸盐含量的多晶橄榄石的主要传导机制。此外，多晶橄榄石与亚铬酸盐相互连接的电导率（10^–1.5 –10 ^0.5  S / m）为俯冲相关构造环境中的高电导率异常提供了合理的解释。