中文摘要：

用微束矿物学和激光拉曼光谱等分析测试技术，并结合人工高压实验结果，研究了我国随州陨石冲击熔脉中的白磷钙石高压相变形成涂氏磷钙石的必要条件，并对寺巷口陨石冲击熔脉中的白磷钙石虽与林伍德石、镁铁榴石和玲根石等高压矿物共生，但仅表现为结构损伤而未相变成涂氏磷钙石的原因进行了探讨。研究结果发现，随州陨石中自磷钙石或氯磷灰石的存在是涂氏磷钙石得以形成的物质前提，陨石熔脉中高达24GPa和2000℃以上的高压高温环境是涂氏磷钙石能够形成的条件保障，而压力释放后熔脉极快的冷却速率是涂氏磷钙石得以淬火并稳定保存的关键。研究还查明，寺巷口陨石冲击熔脉比随州陨石的熔脉要宽1至2个量级，其冷却速率比随州陨石慢得多，因此，熔脉中早先形成的涂氏磷钙石，可能在脉内较高的冲击后温度影响下，慢慢退变质成白磷钙矿。

英文摘要：

The main conditions of phase transformation of whitlockite to its high-pressure polymorph, tuite, in the shock melt veins of the Suizhou meteorite, were investigated using microbeam mineralogical techniques and Raman spectroscopy, and combined with the experimental study at high pressures and temperatures. The reason of the only presence of shocked whitlockite coexisted with ringwoodite, majorite, and lingunite in the shock melt veins of the Sixiangkou meteorite are also discussed in this paper. It is revealed that the existence of calcium phosphates, such as whitlockite or chlorapatite in the Suizhou meteorite is the essential material prerequisite for the formation of tuite; the shock-induced very high pressure and temperature regime of 24 GPa and 2000 ℃ in the Suizhou melt veins is the necessary guarantee conditions for phase transformation of whitlockite to tuite, and the extremely high cooling rate in the Suizhou shock veins after the pressure release is the crux of the matter in quenching and preserving of the shock-produced tuite. It has also been found that the reason of presence of only shock-distorted whitlockite in the Sixiangkou shock melt veins instead of formation of tuite is that the cooling rate in thick melt vein of Sixiangkou is much slower than that in very thin veins of Suizhou, and the high enough post-shock temperature leads the shock-produced tuite to return gradually to its host whitlockite through retrogressive metamorphism.