Shock recovery experiments were conducted using ALH-78084 H3 and Y-793375 L3 chondrites in the shock pressure range of 11–43 GPa to reproduce shock-induced melting and chondrule flattening. Shock-induced melt and chondrule flattening in 15 H3, 23 L3, and 23 LL3 ordinary chondrites were also investigated for comparisons. The shock experiments proved that, at least in unequilibrated ordinary chondrites, shock-induced melting occurred beyond 11 GPa. The melting occurs at the boundary between chondrule and matrix. The melts included fine-grained silicate minerals, glasses, and ameba or spherical metallic Fe–Ni or metallic Fe–Ni–iron sulfide with a eutectic texture that coincided with shock-induced melts in the investigated H/L/LL3 ordinary chondrites. Shock experiments also proved that shock-induced flattening of chondrules occurs and the flattening degree increases with increasing shock pressure. Considering the shock experiments not only of ordinary chondrites but also of carbonaceous chondrites, the flattening degree is not significantly affected by the density, porosity, and chondrule/matrix ratio of chondrites. The long axes of chondrules in shocked ALH-78084 H3 and Y-793375 L3 chondrites have preferred orientations and the degree increases with increasing shock pressure. It is difficult to estimate quantitatively the shock pressure recorded in unequilibrated ordinary chondrites using the empirical formula between the aspect ratio of chondrules and shock pressure. Nevertheless, the investigated L/LL3 ordinary chondrites with shock-induced melts had higher aspect ratios (median, 1.36) and more strongly preferred orientations than those without shock-induced melts (median, 1.25).

中文翻译：

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非平衡球粒陨石的冲击恢复实验使球粒变平

使用 ALH-78084 H3 和 Y-793375 L3 球粒陨石在 11-43 GPa 的冲击压力范围内进行冲击恢复实验，以重现冲击引起的熔化和球粒变平。还研究了 15 个 H3、23 个 L3 和 23 个 LL3 普通球粒陨石中冲击引起的熔化和球粒变平以进行比较。冲击实验证明，至少在未平衡的普通球粒陨石中，冲击引起的熔化发生在 11 GPa 以上。熔化发生在球粒和基质之间的边界处。熔体包括细粒硅酸盐矿物、玻璃和阿米巴或球形金属 Fe-Ni 或金属 Fe-Ni-铁硫化物，具有共晶结构，与研究的 H/L/LL3 普通球粒陨石中的冲击诱导熔体一致。冲击实验也证明了冲击引起的球粒扁平化，扁平化程度随着冲击压力的增加而增加。考虑到普通球粒陨石和碳质球粒陨石的冲击实验，球粒陨石的密度、孔隙度和球粒/基质比对扁平化程度没有显着影响。受到冲击的 ALH-78084 H3 和 Y-793375 L3 球粒陨石中的球粒长轴具有优先取向，并且程度随着冲击压力的增加而增加。使用球粒长径比与冲击压力之间的经验公式很难定量估计非平衡普通球粒陨石中记录的冲击压力。尽管如此，所研究的具有冲击诱导熔体的 L/LL3 普通球粒陨石具有更高的纵横比（中值，1。