کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
1772907 1021072 2016 13 صفحه PDF سفارش دهید دانلود کنید
عنوان انگلیسی مقاله
Elevated bulk-silica exposures and evidence for multiple aqueous alteration episodes in Nili Fossae, Mars
ترجمه فارسی عنوان
افزایش انبساط سیلیکا فله و شواهدی از چندین قسمت تغییرات آب در نیلی فسا، مریخ
کلمات کلیدی
مریخ، سطح؛ طیف سنجی؛ کانی شناسی؛ فرآیندهای زمین شناسی؛ مشاهدات مادون قرمز
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم فضا و نجوم
چکیده انگلیسی


• Thermal-infrared measurements reveal elevated bulk-silica exposures in Nili Fossae, Mars.
• Elevated bulk-silica exposures likely represent the localized alteration of the Nili Fossae capping unit.
• All three main stratigraphic units in Nili Fossae show evidence for variable amounts of aqueous activity and alteration.

The Nili Fossae region of Mars contains some of the most mineralogically diverse bedrock on the planet. Previous studies have established three main stratigraphic units in the region: a phyllosilicate-bearing basement rock, a variably altered olivine-rich basalt, and a capping rock. Here, we present evidence for the localized alteration of the northeast Nili Fossae capping unit, previously considered to be unaltered. Both near-infrared and thermal-infrared spectral datasets were analyzed, including the application of a method for determining the relative abundance of bulk-silica (SiO2) over surfaces using thermal emission imaging system (THEMIS) images. Elevated bulk-silica exposures are present on surfaces previously defined as unaltered capping rock. Given the lack of spectral evidence for phyllosilicate, hydrated silica, or quartz phases coincident with the newly detected exposures—the elevated bulk-silica may have formed under a number of aqueous scenarios, including as a product of the carbonation of the underlying olivine-rich basalt under moderate water: rock scenarios and temperatures. Regardless of formation mechanism, the detection of elevated bulk-silica exposures in the Nili Fossae capping unit extends the history of aqueous activity in the region to include all three of the main stratigraphic units.

Figure optionsDownload high-quality image (76 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 276, 15 September 2016, Pages 39–51
نویسندگان
, ,