The fabrics of the ~ 2200-year-old Wolfenden tufa deposit in southeastern British Columbia, western Canada, are characterized by innumerable radial spar-encrusted peloids of microbial-mediated micrite that partially to completely infilled the pervasive moldic porosity. Coalesced arrays of adjoined spheroids formed concentric growth layers within the moldic porosity. Peloid interiors, as well as other fabrics that encrust bryophyte biota and cyanobacteria, consist of micrite and microspar, rod-shaped mineralized EPS filaments, nanospheroids and hemispheroids of amorphous calcium carbonate (ACC), and monohydrocalcite (MHC) crystallites. The adsorption of EPS molecules in the calcium carbonate precipitate initially regulated the progressive dehydration of the ACC, thereby controlling the ACC–MHC–micrite transformation and ensured the preservation of the ACC nanospheroids as the initial stage of the transformation. This transformation sequence controlled the interior ultrastructure and mineralogy of the biogenic peloids. The mineral transformation sequence was altered by diminished adsorption of EPS-derived organic molecules and increased dominance of Mg²⁺ adsorption. This resulted in a direct ACC–calcite transformation without the intermediate MHC stage. This shift in the biotic-mediated/abiotic balance was concurrent with neomorphism of the peloid interiors and development of radial-spar cortices. The dominant Mg²⁺ adsorption resulted in a meshwork of needle-fiber calcite crystals within biofilm canopies on moldic porosity surfaces and ACC–MHC–calcite encrusted biota. In contrast, dominant abiotic Mg²⁺ adsorption without enveloping biofilms triggered the morphogenesis of individual needle-fiber calcite crystals during split crystallization. Neomorphism of the microbial-mediated calcite crystal structures with metallic ion adsorption permitted radial spar-jacketed peloids transforming into small ovoid crystal fans or bundles that recrystallized earlier cyanobacterial frameworks. Split crystallization enhanced this process as larger ovoid crystal fans expanded into abiotic radial-starburst arrays of bladed crystals as growth layers of moldic porosity.

加拿大西部不列颠哥伦比亚省东南部约 2200 年历史的 Wolfenden 凝灰岩矿床的结构的特征是无数径向晶石镶嵌的微生物介导的泥晶球体，部分或完全填充了普遍存在的铸模孔隙。相邻球体的聚结阵列在铸模孔隙中形成同心生长层。Peloid 内部，以及包裹苔藓植物生物群和蓝藻的其他织物，由泥晶和微晶石、棒状矿化 EPS 细丝、无定形碳酸钙 (ACC) 的纳米球体和半球体以及单水方解石 (MHC) 微晶组成。EPS分子在碳酸钙沉淀物中的吸附最初调节了ACC的进行性脱水，从而控制ACC-MHC-微晶转化并确保ACC纳米球体作为转化初始阶段的保存。这种转化顺序控制了生物成因球体的内部超微结构和矿物学。EPS 衍生的有机分子的吸附减少和 Mg 的优势增加改变了矿物转化顺序²⁺吸附。这导致没有中间 MHC 阶段的直接 ACC-方解石转化。这种生物介导/非生物平衡的转变与球体内部的新形态和径向晶石皮质的发育同时发生。主要的 Mg ²⁺吸附导致在铸模孔隙表面和 ACC-MHC-方解石包裹的生物群上的生物膜冠层内形成针状纤维方解石晶体的网状结构。相反，占主导地位的非生物 Mg ²⁺没有包裹生物膜的吸附在分裂结晶过程中触发了单个针状纤维方解石晶体的形态发生。具有金属离子吸附的微生物介导的方解石晶体结构的新形态允许径向晶石夹套的球状物转变为小的卵形晶体扇形或束，使早期的蓝藻骨架重结晶。分裂结晶增强了这一过程，因为较大的卵形晶体扇形扩展成叶片状晶体的非生物径向星暴阵列，作为铸模孔隙的生长层。