We report infrared reflectance and ultraviolet fluorescence spectra of the surfaces and cleaved side of Beacon Sandstone from Antarctica that harbours a cryptoendolithic microbial community - a photosynthesis-based consortium of algae, lichen and bacteria present a few millimetres below the surface. Chlorophyll absorptions were present in the reflectance spectra of the exposed interior but not on the top or bottom surfaces and their band depths changed < 4% between measurements taken 19 years apart, indicating the stability of the microorganisms when the sample is kept dry. The presence of subsurface organic layers was detected in reflectance at 3.41 μm on the sample's surface. Fluorescence spectra of the cleaved side showed the blue fluorescence peaks expected from chlorophyll but no 0.65–0.80 μm peaks seen in fluorescence measurements of green vegetation. A weak fluorescence signal was detectable at the surface of the sample, presumably due to some light leaking into the subsurface through pores or cracks in the goethite coating the sample's surface. Theoretically, this weak fluorescence signal could possibly be observed in rock surfaces broken by erosion or meteor impacts on Mars. Sandstone outcrops have been reported on Mars and detection of organic layers in sandstones there would be of interest.

中文翻译：

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南极砂岩中微生物定殖的光谱检测

我们报告了来自南极洲的 Beacon 砂岩的表面和劈裂面的红外反射和紫外荧光光谱，该砂岩含有隐内石微生物群落——一种基于光合作用的藻类、地衣和细菌的联合体，存在于地表以下几毫米处。叶绿素吸收存在于暴露内部的反射光谱中，但不存在于顶部或底部表面，并且它们的带深度在相隔 19 年的测量之间变化 < 4%，表明当样品保持干燥时微生物的稳定性。在样品表面 3.41 μm 处的反射率中检测到地下有机层的存在。切割侧的荧光光谱显示了叶绿素预期的蓝色荧光峰，但没有 0.65-0。在绿色植被的荧光测量中看到 80 μm 的峰。在样品表面可检测到微弱的荧光信号，这可能是由于一些光通过样品表面上的针铁矿中的孔或裂缝泄漏到地下。从理论上讲，这种微弱的荧光信号可能在被火星侵蚀或流星撞击破坏的岩石表面中观察到。据报道，火星上有砂岩露头，在砂岩中检测有机层将引起人们的兴趣。这种微弱的荧光信号可能在被火星侵蚀或流星撞击破坏的岩石表面中观察到。据报道，火星上有砂岩露头，在砂岩中检测有机层将引起人们的兴趣。这种微弱的荧光信号可能在被火星侵蚀或流星撞击破坏的岩石表面中观察到。据报道，火星上有砂岩露头，在砂岩中检测有机层将引起人们的兴趣。