Cooling fractures in impact melt deposits on the Moon and Mercury: Implications for cooling solely by thermal radiation
Cooling fractures in impact melt deposits on the Moon and Mercury: Implications for cooling solely by thermal radiation
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月球和水星上冲击熔体沉积物的冷却裂缝：仅通过热辐射冷却的影响
DOI：
10.1002/2013je004560
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发表时间：
2014-07
影响因子：
4.8
通讯作者：
Xiao Long
中科院分区：
文献类型：
--
作者：
Xiao Zhiyong;Zeng Zuoxun;Li Zhiyong;Blair David M.;Xiao Long
我们研究了月球和水星上几个年轻的撞击熔体沉积物中的裂缝的分布、形态和几何性质，以及这些裂缝可能是通过热辐射冷却而形成的。在每个冲击熔体复合体中，下伏地形的地形决定了冷却裂缝的方向，因此在熔体单元相对较厚的内部区域形成的内部裂缝比在单元边缘附近相对较薄的区域形成的边缘裂缝更宽、间距更大。夹带在熔融沉积物中的固体碎片提供了裂缝前的缺陷，这可能会导致冷却裂缝的萌生，但过多的固体碎片会阻止冷却裂缝扩展到宏观尺寸。亚平行断口的出现主要是由于冷却和凝固过程中沉积物的下沉引起的。热辐射引起的拉应力足够大，足以在月球和水星上引发冷却断裂，这可能代表柱状接头形成的初始阶段，但仅由热辐射引起的冷却速度不足以形成组织良好的柱状接头，具有多边形柱廊。因此，我们认为热传导和对流是形成行星体柱状节理的主要因素。
We study the distribution, morphology, and geometrical properties of fractures in several young impact melt deposits on the Moon and Mercury, and the ways that these fractures may form from cooling by thermal radiation. In each impact melt complex, the topography of the underlying terrain determines the orientation of cooling fractures, such that interior fractures that formed in the relatively thick interior areas of the melt unit are wider and have a larger spacing than marginal fractures that formed in the relatively thin areas near the unit's margins. Solid debris entrained in molten deposits provides prefracture flaws that can seed cooling fractures, but too much solid debris prevents cooling fractures from growing to macroscopic sizes. The appearance of subparallel fractures is mainly caused by subsidence of the deposits during the process of cooling and solidification. Tensile stresses caused by thermal radiation are large enough to initiate cooling fractures on both the Moon and Mercury, which may represent the initial stage of columnar joints formation, but the cooling rate caused solely by thermal radiation is not large enough to form well‐organized columnar joints that feature polygonal colonnades. We therefore propose that thermal conduction and convection are the major contributors in the formation of columnar joints on planetary bodies.
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DOI：
10.1103/physreve.71.056122
发表时间：
2005-05
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
T. Mizuguchi;A. Nishimoto;S. Kitsunezaki;Y. Yamazaki;I. Aoki
通讯作者：
T. Mizuguchi;A. Nishimoto;S. Kitsunezaki;Y. Yamazaki;I. Aoki
影响因子：
2.6
作者：
Manabu Kato;S. Sasaki;K. Tanaka;Y. Iijima;Y. Takizawa
通讯作者：
Manabu Kato;S. Sasaki;K. Tanaka;Y. Iijima;Y. Takizawa
影响因子：
5.3
作者：
Zhiyong Xiao;Z. Zeng;N. Ding;J. Molaro
通讯作者：
Zhiyong Xiao;Z. Zeng;N. Ding;J. Molaro
影响因子：
10.3
作者：
D. Stöffler;G. Ryder
通讯作者：
D. Stöffler;G. Ryder
影响因子：
3.2
作者：
C. Klimczak;R. Schultz;A. Nahm
通讯作者：
C. Klimczak;R. Schultz;A. Nahm