The role of early Archean Terrestrial Environments in Weathering, Sediment Transport, and the Colonization of Land

太古代陆地地层保存了一个独特的和潜在的有价值的记录，允许限制地质，生物和大气之间的相互作用的历史：它包括古土壤形成的条件，强度和类型的风化和沉积物生成和成熟的过程。最古老的保存（微生物）痕迹的早期生活在陆地上承担基本的地理生物相互作用，如机制和程度的营养输送，辐射避免的策略，和大气成分。风成地层可能传递独特的环境参数，如当地的风力和大气密度，与干旱和循环系统的影响。最后，陆源碎屑岩与温度、蒸发和地下水运动有关。虽然太古宙的陆地沉积体系是罕见的，而且由于许多原因，通常保存不好，但它们的潜在价值值得对其进行详细的研究。我建议专题调查的早太古代（3.22 Ga）穆迪集团，南非世界上最古老的风成地层据称已被报道。我们的初步调查已经记录了微生物席，蒸发岩结核，和沉积角砾岩单位，但迄今尚未成功地确认风成地层。地质填图、剖面测量、结构研究、蒸发岩分析和砂岩岩石学将约束陆地环境，提高我们对太古代陆地过程的了解，并约束相关的SPP研究项目。洞察力甚至可能延伸到火星上的条件，那里的水环境（现在）要脆弱得多。

Archean terrestrial strata preserve a unique and potentially valuable record which allows to constrain the history of interaction between geo-, bio and atmosphere: It includes conditions of paleosol formation, intensity and type of weathering and processes of sediment generation and maturation. The oldest preserved (microbial) traces of early life on land bear on fundamental geo-bio-interactions such as mechanism and degree of nutrient delivery, strategies of radiation avoidance, and atmospheric composition. Eolian strata may convey unique environmental parameters such as local wind strength and atmospheric density, with implications for aridity and circulatory systems. Lastly, terrestrial evaporites relate to temperature, evaporation and groundwater movement. Although Archean terrestrial depositional systems are rare and generally poorly preserved for a number of reasons, their potential value warrants their detailed investigation. I suggest the topical investigation of the Early Archean (3.22 Ga) Moodies Group, South Africa from which the world’s oldest purportedly eolian strata have been reported. Our preliminary surveys have documented microbial mats, evaporite concretions, and a sedimentary breccia unit but to-date been unsuccessful in confirming eolian strata. Geological mapping, section measuring, textural studies, evaporite analysis and sandstone petrography will constrain the terrestrial settings, improve our understanding of Archean terrestrial processes and constrain related SPP research projects. Insights may even extend to conditions on Mars where aqueous environments were (and are) far more tenuous.