Selective dissolution of metastable minerals and certain pore types, such as moldic and oomoldic pores, are widely accepted to indicate diagenesis by meteoric fluids in carbonate rocks. In this study, oomoldic-rich re-sedimented carbonates from the Happy Field in the Midland Basin, which contain no evidence of subaerial environments, indicate that such pores may form in other settings. Ooid dissolution in the reservoir was evaluated through petrography, scanning electron microscopy, stable isotopes (δ¹⁸O and δ¹³C), elemental geochemistry, and X-ray diffraction of bioclasts, ooids and associated cements. Cements are primarily dogtooth and equant low-magnesium calcite, poikilotopic celestine is present, and late-stage low-magnesium calcite occurs in lesser amounts. Equant low magnesium calcite cements are interpreted to reflect the initial stages of pore filling, synchronous with aragonitic ooid dissolution, thus implying that oomoldic pores and equant cements formed in similar fluids. Although the prominent equant low magnesium calcite cement textures mimic those often associated with meteoric fluids, geochemistry suggests a marine origin. The equant cements have δ¹⁸O (Vienna Pee Dee Belemnite) ratios between −2.0‰ and −3.5‰, and δ¹³C (Vienna Pee Dee Belemnite) ratios between 4‰ and 5‰. Magnesium/calcium ratios show values, ranging from 5 to 142 mmol/mol (n = 223, average 23.2 and SD = 20.1). Strontium/calcium ratios present values from 0.3 to 2.6 mmol/mol (n = 223, average 0.71 mmol/mol, SD = 0.35). Geochemical data coincide with typical low-latitude Permian marine carbonate values and further signify diagenesis within the marine phreatic realm. To explain this process, the results indicate that the dissolution of aragonite ooids and precipitation of early cements occurred in environments ranging between the seafloor to shallow burial dominated by undersaturated marine fluids. Undersaturation was triggered by organic matter decomposition occurring at the seafloor and in the shallow subsurface immediately below. These findings have broader implications for marine and burial carbonate diagenesis as well as diagenesis of re-sedimented deposits.

中文翻译：

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鲕类在海水衍生流体中的溶解——以美国西德克萨斯州下二叠纪再沉积碳酸盐为例

亚稳矿物和某些孔隙类型（如铸模孔和铸模孔）的选择性溶解被广泛接受，以表明碳酸盐岩中大气流体的成岩作用。在这项研究中，来自米德兰盆地 Happy Field 的富含 omoldic 的再沉积碳酸盐表明，这些孔隙可能在其他环境中形成，其中没有地下环境的证据。通过岩相学、扫描电子显微镜、稳定同位素（δ ¹⁸ O 和 δ ¹³C)、元素地球化学和生物碎屑、鲕粒和相关胶结物的 X 射线衍射。水泥主要是犬齿状和等价低镁方解石，存在异色天青石，后期低镁方解石的含量较少。Equant 低镁方解石胶结物被解释为反映孔隙充填的初始阶段，与文石鲕粒溶解同步，因此暗示在相似的流体中形成了 omoldic 孔和 Equant 胶结物。尽管突出的等离子低镁方解石水泥质地模仿了那些通常与流星流体相关的质地，但地球化学表明它是海洋起源的。Equant 水泥的δ ¹⁸ O（Vienna Pee Dee Belemnite）比率在-2.0‰和-3.5‰之间，δ ¹³C (Vienna Pee Dee Belemnite) 比例在 4‰ 到 5‰ 之间。镁/钙比率显示值，范围从 5 到 142 mmol/mol（n = 223，平均 23.2 和 SD = 20.1）。锶/钙比值从 0.3 到 2.6 mmol/mol（n = 223，平均 0.71 mmol/mol，SD = 0.35）。地球化学数据与典型的低纬度二叠纪海洋碳酸盐值一致，进一步表明海洋潜水领域内的成岩作用。为了解释这个过程，结果表明文石鲕粒的溶解和早期胶结物的沉淀发生在海底到浅埋层之间，以不饱和海洋流体为主。不饱和是由发生在海底和正下方浅层地下的有机物质分解引发的。