Valleys, paleolakes and possible shorelines at the Libya Montes/Isidis boundary: Implications for the hydrologic evolution of Mars

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• 作者：G. Erkeling^a ; ^{gino.erkeling@uni-muenster.de} ; D. Reiss^a ; H. Hiesinger^a ; F. Poulet^b ; J. Carter^b ; M.A. Ivanov^c ; E. Hauber^d ; R. Jaumann^d
• 关键词：Mars ; Mars ; Surface ; Mars ; Climate ; Mars ; Atmosphere ; Mineralogy
• 刊名：Icarus
• 出版年：2012
• 期刊代码：90_00191035
• 类别：ph
• 出版时间：May, 2012
• 卷：219
• 期：1
• 页码：393-413
• 文件大小：6181 K

摘要

We describe the results of our morphologic, stratigraphic and mineralogic investigations of fluvial landforms, paleolakes and possible shoreline morphologies at the Libya Montes/Isidis Planitia boundary. The landforms are indicative of aqueous activity and standing bodies of water, including lakes, seas and oceans, that are attributed to a complex hydrologic cycle that may have once existed on Mars in the Noachian (>3.7 Ga) and perhaps also in the Hesperian (>3.1 Ga). Our observations of the Libya Montes/Isidis Planitia boundary between 85掳/86.5掳E and 1.8掳/5掳N suggest, that (1) the termination of valley networks between roughly 鈭?500 and 鈭?800 m coincide with lake-size ponding in basins within the Libya Montes, (2) an alluvial fan and a possible delta, layered morphologies and associated Al-phyllosilicates identified within bright, polygonally fractured material at the front of the delta deposits are interpreted to be the results of fluvial activity and discharge into a paleolake, (3) the Arabia 鈥渟horeline鈥?appears as a series of possible coastal cliffs at about 鈭?600 and 鈭?700 m indicating two distinct still stands and wave-cut action of a paleosea that temporarily filled the Isidis basin the Early Hesperian, and (4) the Deuteronilus 鈥渟horeline鈥?appears at 鈭?800 m and is interpreted to be a result of the proposed sublimation residue of a frozen sea that might have filled the Isidis basin, similar to the Vastitas Borealis Formation (VBF) identified in the northern lowlands. We interpret the morphologic-geologic setting and associated mineral assemblages of the Libya Montes/Isidis Planitia boundary as results of fluvial activity, lake-size standing bodies of water and an environmental change over time toward decreasing water availability and a cold and dry climate.