Department of Electrical Engineering, UC Santa Cruz, Santa Cruz, CA 95060, USA.
Appl Spectrosc. 2012 Aug;66(8):911-6. doi: 10.1366/11-06523. Epub 2012 Jul 13.
Raman spectroscopy has promising potential for future Mars missions as a non-contact detection technique for characterizing organic material and mineralogy. Such a capability will be useful for selecting samples for detailed analysis on a rover and for selecting samples for return to Earth. Stromatolites are important evidence for the earliest life on Earth and are promising targets for Mars investigations. Although constructed by microorganisms, stromatolites are organo-sedimentary structures that can be large enough to be discovered and investigated by a Mars rover. In this paper, we report the Raman spectroscopic investigations of the carbonate mineralogy and organic layering in a Precambrian (~1.5 Gyr old) stromatolite from the Crystal Spring Formation of Southern California. Ultraviolet (UV: 266 nm), visible (514 nm, 633 nm), and near-infrared (NIR: 785 nm, 1064 nm) Raman spectra are presented. We conclude that 1064 nm excitation is the optimal excitation wavelength for avoiding intrinsic fluorescence and detecting organic carbon within the carbonate matrix. Our results confirm that NIR Raman spectroscopy has important applications for future Mars missions.
拉曼光谱技术在未来的火星任务中具有广阔的应用前景，它是一种非接触式检测技术，可以用于有机物质和矿物学的特征分析。这种能力将有助于在火星车上选择用于详细分析的样本，以及选择返回地球的样本。叠层石是地球上最早生命的重要证据，也是火星探测的有前途的目标。尽管是由微生物建造的，但叠层石是有机-沉积结构，其体积大到足以被火星车发现和研究。在本文中，我们报告了对来自加利福尼亚州南部水晶泉组的前寒武纪（约 15 亿年）叠层石的碳酸盐矿物学和有机层状结构的拉曼光谱研究。我们展示了紫外（UV：266nm）、可见（514nm、633nm）和近红外（NIR：785nm、1064nm）拉曼光谱。我们得出结论，1064nm 激发是避免固有荧光并在碳酸盐基质中检测有机碳的最佳激发波长。我们的结果证实，近红外拉曼光谱在未来的火星任务中具有重要的应用价值。
