Knoll A H, Swett K, Burkhardt E
Botanical Museum, Harvard University, Cambridge, Massachusetts 02138, USA.
J Paleontol. 1989;63(2):129-45.
The Upper Proterozoic (ca. 700-800 Ma old) Backlundtoppen Formation, northeastern Spitsbergen, preserves an abundant and varied record of ancient microbial life. Five distinctive microfossil assemblages occur in five equally distinct sedimentary settings; differences among the assemblages appear to reflect original ecological heterogeneity, although taphonomic circumstance may contribute to some distinctions. Microfossil assemblages occur in: oncolites, oolites, and pisolites; stratiform stromatolites and associated intraclastic rudites; partially silicified micrites; and siltites interbedded with quartz arenites. Individual assemblages contain one to eight differentiable taxa; a minimum of 17 distinct populations is present in the formation as a whole. Additional microbial community diversity an be inferred from the presence of domal, columnar, pseudocolumnar, and coniform stromatolites, none of which contains microfossils. On the basis of macrostructure, four stromatolite types appear to be present, but only three distinct mat-building communities can be inferred from microstructural features. Eohyella elongata n. sp., a euendolithic cyanobacterium found in silicified pisolites, is described as new.
斯匹次卑尔根群岛东北部上元古界（约7亿至8亿年前）的巴克伦托彭组保存了丰富多样的古代微生物生命记录。五个独特的微化石组合出现在五个同样独特的沉积环境中；尽管埋藏环境可能导致一些差异，但组合之间的差异似乎反映了原始的生态异质性。微化石组合出现在：核形石、鲕粒和豆粒；层状叠层石及相关的内碎屑粗粒岩；部分硅化的微晶灰岩；以及与石英砂岩互层的粉砂岩中。单个组合包含一至八个可区分的分类单元；整个地层中至少存在17个不同的种群。从穹顶状、柱状、假柱状和锥形叠层石的存在可以推断出更多的微生物群落多样性，这些叠层石中都不含微化石。基于宏观结构，似乎存在四种叠层石类型，但从微观结构特征只能推断出三个不同的造席群落。在硅化豆粒中发现的一种内生蓝藻新种——细长始古藻被描述为新物种。
