The Aptian lacustrine carbonates of the Barra Velha Formation, offshore Brazil, have undergone a highly unusual paragenetic and diagenetic history and present significant terminological problems if current textural classifications are applied. Existing limestone classifications invoke the concept of textural maturity, whereby the ratio of matrix to grain is a critical property and can be used to infer energy levels and the degree of transport prior to deposition. In the Barra Velha Formation, some critical carbonate grains grew in a matrix which later dissolved, congruently, producing what appears to be primary intergranular porosity. In addition, apparent boundstone textures occur, not due to organic trapping or binding, but ones which can be shown to be diagenetic, and were also related in part to the former presence of labile matrices. Thus, applying some terms in existing classifications can lead to false interpretations, and to avoid misinterpretations criteria for identifying ghost (former) matrices are provided.

中文翻译：

---

巴西近海桑托斯盆地白垩纪 Barra Velha 组碳酸盐岩的结构演化和鬼矩阵

巴西近海 Barra Velha 组的 Aptian 湖相碳酸盐岩经历了非常不寻常的共生和成岩历史，如果应用当前的构造分类，则存在重大的术语问题。现有的石灰岩分类引用了结构成熟度的概念，其中基质与颗粒的比率是一个关键属性，可用于推断沉积前的能量水平和传输程度。在 Barra Velha 地层中，一些关键的碳酸盐颗粒在基质中生长，随后一致地溶解，产生似乎是原生粒间孔隙。此外，出现明显的边界石纹理，不是由于有机物捕获或结合，而是由于成岩作用，并且部分与以前不稳定基质的存在有关。因此，