Walsh M M
Department of Geology and Geophysics, Louisiana State University, Baton Rouge 70803, USA.
Precambrian Res. 1992;54:271-93. doi: 10.1016/0301-9268(92)90074-x.
There is widespread textural evidence for microbial activity in the cherts of the Early Archean Onverwacht Group. Layers with fine carbonaceous laminations resembling fossil microbial mats are abundant in the cherty metasediments of the predominantly basaltic Hooggenoeg and Kromberg Formations. In rare cases, filamentous microfossils are associated with the laminae. The morphologies of the fossils, as well as the texture of the encompassing laminae suggest an affinity to modern mat-dwelling cyanobacteria or bacteria. A variety of spheroidal and ellipsoidal structures present in cherts of the Hooggenoeg and Kromberg Formations resemble modern coccoidal bacteria and bacterial structures, including spores. The development of spores may have enabled early microorganisms to survive the relatively harsh surficial conditions, including the effects of very large meteorite impacts on the young Earth.
有广泛的纹理证据表明，太古代早期翁弗瓦赫特群的燧石中存在微生物活动。在以玄武岩为主的霍赫内格组和克龙贝格组的燧石变质沉积物中，有许多具有类似化石微生物席的精细碳质纹层的层。在极少数情况下，丝状微化石与这些纹层有关。化石的形态以及周围纹层的纹理表明，它们与现代生活在微生物席中的蓝细菌或细菌有亲缘关系。霍赫内格组和克龙贝格组燧石中存在的各种球状和椭球状结构类似于现代的球菌类细菌和细菌结构，包括孢子。孢子的发育可能使早期微生物能够在相对恶劣的地表条件下生存，包括非常大的陨石撞击对年轻地球的影响。
