We present a multidisciplinary analysis of Lermontov crater, located at 15.24°N, −48.94°E in the Kuiper quadrangle of Mercury. By means of MESSENGER multiband MDIS-WAC and monochrome MDIS-NAC images, we prepare a high-resolution geological map of the crater and its closest surroundings, highlighting the presence of coexisting hollows and pyroclastic deposits on its floor. On the photometrically corrected MDIS-WAC multiband dataset, we apply an unsupervised clustering technique that spectrally separates the different materials located both inside and outside Lermontov crater. We observe that the pyroclastic deposits located on the crater’s floor have a steep, red spectral behaviour dominated by the presence of a mixture of various pyroxenes containing Ti and Ni. On the contrary, the vents’ rims are characterised by several hollows whose spectral slope is bluer than that of the pyroclastic deposits. By comparing the vent hollows to the hollows located farther out on the crater floor, we observe a steeper 0.62–0.82 ​μm spectral trend for those within the vents. The vent hollows’ spectrum is more similar to the pyroclastic one in the above mentioned wavelength range. In addition, the vent hollows 0.55 ​μm absorption band could be related to CaS, while the small differences in slope at 0.48 ​μm and 0.62 ​μm could be due to the presence of other volatiles compounds, such as MgS or chlorides. When compared to hollows located in other hermean geological settings, Lermontov hollows are characterised by steeper spectra. This supports the interpretation that when hollows form, their bright deposits do not completely overwrite the spectral signature of the surrounding terrain, and their spectroscopic appearance is mixed with the composition of the terrain where they form.

中文翻译：

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水星上的莱蒙托夫陨石坑：共存空洞和火山碎屑沉积物的地质、形态和光谱特性

我们对位于水星柯伊伯四边形北纬 15.24°，东经-48.94°的莱蒙托夫陨石坑进行了多学科分析。通过 MESSENGER 多波段 MDIS-WAC 和单色 MDIS-NAC 图像，我们准备了陨石坑及其最近周围环境的高分辨率地质图，突出显示了其底部共存的空洞和火山碎屑沉积物。在经过光度校正的 MDIS-WAC 多波段数据集上，我们应用了无监督聚类技术，该技术可以对位于莱蒙托夫陨石坑内部和外部的不同材料进行光谱分离。我们观察到，位于陨石坑底部的火山碎屑沉积物具有陡峭的红色光谱行为，主要是由于含有钛和镍的各种辉石混合物的存在。相反，喷口边缘的特征是有几个空洞，其光谱斜率比火山碎屑沉积物的光谱斜率更蓝。通过将通风口空洞与火山口底部较远的空洞进行比较，我们观察到通风口内的空洞具有更陡峭的 0.62–0.82 μm 光谱趋势。在上述波长范围内，通风孔的光谱与火山碎屑的光谱更相似。此外，排气孔 0.55 μm 吸收带可能与 CaS 有关，而 0.48 μm 和 0.62 μm 处斜率的微小差异可能是由于存在其他挥发性化合物，例如 MgS 或氯化物。与其他地质环境中的空洞相比，莱蒙托夫空洞的特征是光谱更陡。这支持了这样的解释：当空洞形成时，它们明亮的沉积物不会完全覆盖周围地形的光谱特征，并且它们的光谱外观与它们形成的地形的成分混合在一起。