Hunan Provincial Key Laboratory of Shale Gas Resource Utilization, Hunan University of Science and Technology, Xiangtan, Hunan, China.
Sci Prog. 2021 Apr-Jun;104(2):368504211019859. doi: 10.1177/00368504211019859.
The new Cuban chondrite, Viñales, fell on February first, 2019 at Pinar del Rio, northwest of Cuba (22°37'10″N, 83°44'34″W). A total of about 50-100 kg of the meteorite were collected and the masses of individual samples are in a range 2-1100 g. Two polished thin sections were studied by optical microscope, Raman spectroscopy and electron microprobe analysis in this study. The meteorite mainly consists of olivine (Fa), low-Ca pyroxene (Fs), and troilite and Fe-Ni metal, with minor amounts of feldspar (Ab). Three poorly metamorphosed porphyritic olivine-pyroxene and barred olivine chondrules are observed. The homogeneous chemical compositions and petrographic textures indicate that Viñales is a L6 chondrite. The Viñales has fresh black fusion crust with layered structure, indicating it experienced a high temperature of ∼1650°C during atmospheric entry. Black shock melt veins with width of 100-600 μm are pervasive in the Viñales and olivine, bronzite, and metal phases are dominate minerals of the shock melt vein. The shock features of major silicate minerals suggest a shock stage S3, partly S4, and the shock pressure could be >10 GPa.
新的古巴球粒陨石“比尼亚莱斯”于 2019 年 2 月 1 日降落在古巴西北部的比那尔德里奥（北纬 22°37'10″，西经 83°44'34″）。共收集到约 50-100 公斤陨石，单个样品的质量在 2-1100 克之间。本研究通过光学显微镜、拉曼光谱和电子探针分析对两块抛光薄片进行了研究。陨石主要由橄榄石（Fa）、低钙辉石（Fs）和陨硫铁和铁镍金属组成，还有少量长石（Ab）。观察到三个未变质的斑状橄榄石-辉石和条带状橄榄石球粒。均匀的化学成分和岩相结构表明，“比尼亚莱斯”是一种 L6 球粒陨石。“比尼亚莱斯”具有新鲜的黑色熔融壳，具有层状结构，表明它在进入大气层时经历了约 1650°C 的高温。黑色冲击熔融脉广泛存在于“比尼亚莱斯”中，宽度为 100-600μm，冲击熔融脉的主要矿物为橄榄石、古铜辉石和金属相。主要硅酸盐矿物的冲击特征表明冲击阶段为 S3，部分为 S4，冲击压力可大于 10GPa。
