元阳铁陨石是2010年在云南省元阳县山区发现的，其内部的主要矿物为铁纹石和镍纹石，铁纹石的含量很高(约占80%)，镍纹石的含量较低.铁纹石中Ni含量为4.88–6.21 wt%，镍纹石中Ni含量为26.13–50.27 wt%.副矿物有陨磷铁镍石、闪锌矿和氮铬矿.陨磷铁镍石存在大、小两种颗粒，具有颗粒越大Ni含量越低的特点.元阳铁陨石中没有发现硅酸盐包体.由于经受了地表风化蚀变作用，样品边缘以及铁纹石裂隙间都发生了氧化.元阳铁陨石中铁纹石的条带宽度较粗，属于粗粒八面体结构.中子活化分析结果显示：元阳铁陨石的Ni(7 wt%)和Au(1.565 ppm)的含量都相对较低，和IAB-MG(IAB-Main group)群的铁陨石在化学成分上具有相似性，属于IAB-MG群.相对于其他IAB-MG群铁陨石，元阳铁陨石的Ir(1.00 ppm)含量偏低，这可能是由于其母体中富含Ir的矿相在冲击作用下并没有完全熔融.%Yuanyang was found in Yunnan in 2010. Yuanyang has a rusted surface, and there are also some corroded materials inside. The major phases in Yuanyang are kamacite (Ni 4.88–6.21 wt%) and taenite (Ni 26.13–50.27 wt%). The minor ones are schreibersite, sphalerite, and carlsbergite. Yuanyang is a coarse octahedrite with a high content of kamacite (80 vol%). No silicate inclusions are found in Yuanyang. The instrumental neutron activation analysis (INAA) of Yuanyang reveals that it is a low-Ni (7 wt%) and low-Au (1.565 ppm) iron. Yuanyang is an IAB-MG iron. The Ir content (1.00 ppm) of Yuanyang is relatively low compared to other IAB-MG irons. This is probably due to the partial melting of Ir-rich phase in its parent body during an impact event.
展开▼
