کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1775793 | 1021207 | 2008 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Distinguishing between vapor- and liquid-formed ground ice in the northern martian regolith and potential for biosignatures preserved in ice bodies
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In this study, various approaches that can potentially distinguish between vapor- and liquid-derived ground ice in the martian regolith (petrography, geochemistry, stable OH isotopes, CO2O2N2Ar gas composition) are examined using terrestrial ground ice examples. Although the stable OH isotope composition ratios can distinguish between vapor- and liquid-derived terrestrial ground ice, there might be to much mixing between the various water reservoirs on Mars to effectively use it, and, like on Earth, petrographic and geochemical approaches need to be complemented with additional supporting evidences. Of the different approaches currently being employed to determine the origin of terrestrial massive ground ice and icy sediments, it is the concentration of CO2 and the O2/Ar, N2/Ar and N2/O2 ratios of air entrapped in the ice that has proven to be the less ambiguous and most discriminatory. This is because the molar ratios of atmospheric gases change during their dissolution in water due to differences in their relative solubilities, thus providing distinctive ratios for the dissolved gases. The gas composition of air entrapped in the ice not only distinguishes between vapor- and liquid-derived ground ice, but any deviation from the theoretical dissolved values can provide insights into potential physical and biological processes operating in the subsurface, a key component for astrobiology.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 197, Issue 2, October 2008, Pages 458-469
Journal: Icarus - Volume 197, Issue 2, October 2008, Pages 458-469
نویسندگان
Denis Lacelle, David Fisher, Ian D. Clark, Alain Berinstain,