Chondrule Flattening by Shock Recovery Experiments on Unequilibrated Chondrites
Chondrule Flattening by Shock Recovery Experiments on Unequilibrated Chondrites
复制标题
不平衡球粒陨石冲击恢复实验使球粒变平
DOI：
10.1029/2021je006864
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Nakamaura A.
中科院分区：
文献类型：
--
作者：
Miyahara M.;Edanaga J.;Yamaguchi A.;Kobayashi T.;Sekine T.;Nakamaura A.
在11-43 GPa的冲击压力范围内，用ALH‐78084 H3和Y‐793375 L3球粒陨石进行了冲击恢复实验，以重现冲击诱导的熔化和球粒变平。还研究了15颗H3、23颗L3和23颗LL3普通球粒陨石的冲击诱导熔化和球粒扁平化的比较。冲击实验证明，至少在非平衡的普通球粒陨石中，冲击诱发的熔化发生在11gpa以上。熔融发生在球粒与基体交界处。熔体包括细粒硅酸盐矿物、玻璃、阿米巴或球状金属Fe-Ni或金属Fe-Ni -硫化铁，具有共晶结构，与所研究的H/L/LL3普通球粒陨石中的激波诱导熔体相一致。冲击实验也证明了冲击诱导的球粒压扁发生，且压扁程度随冲击压力的增加而增加。从普通球粒陨石和碳质球粒陨石的冲击实验来看，球粒陨石的密度、孔隙度和球粒/基体比对其扁化程度影响不大。受冲击的ALH‐78084 H3和Y‐793375 L3球粒的长轴具有优先取向，且程度随冲击压力的增加而增加。利用球粒长径比与冲击压力之间的经验公式，难以定量地估计非平衡普通球粒中记录的冲击压力。然而，与没有激波诱导熔体的L/LL3普通球粒陨石相比，具有激波诱导熔体的L/LL3普通球粒陨石具有更高的纵横比（中位数为1.36）和更强的偏好取向（中位数为1.25）。
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).
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影响因子：
13.6
作者：
M. Weisberg;T. Mccoy;A. Krot
通讯作者：
M. Weisberg;T. Mccoy;A. Krot
西北非 8709：罕见但具有启发性的 3 型普通球粒陨石熔融角砾岩
影响因子：
2.2
作者：
A. Ruzicka;M. Hutson;J. Friedrich;P. Bland;R. Pugh
通讯作者：
R. Pugh
普通球粒陨石中石油结构的起源和磁各向异性
DOI：
10.1111/j.1945-5100.1988.tb00909.x
发表时间：
1988
期刊：
Meteoritics
影响因子：
--
作者：
D. Sneyd;H. McSween;N. Sugiura;D. Strangway;G. Nord
通讯作者：
G. Nord
根据基质的模态和化学变化推断 CM 碳质球粒陨石的变化
DOI：
--
发表时间：
1979
期刊：
影响因子：
--
作者：
H. McSween
通讯作者：
H. McSween
影响因子：
2.2
作者：
Macke, Robert J.;Consolmagno, Guy J.;Britt, Daniel T.
通讯作者：
Britt, Daniel T.