# Diagenetic Study of Marron Emperador Ornamental Stone (Upper Cretaceous, SE Spain)
## 2 Geological Setting
### Dolostone Petrography and Geochemistry  
Table 3 shows the main characteristics of the dolostone fabrics recognised in breccia clasts. The predominant dolomite fabrics recognised in breccia clasts are: (1) medium- to coarsely-crystalline dolosparites composed of hypidiotopic (planar-s) mosaics with crystals rich in impurities (Figure 2); (2) idiotopic (planar-e) mosaics; (3) and microcrystalline types. In these fabrics, the dolomite crystals sometimes show rhombic and subrhombic zones (delimited by alignments of inclusions or impurities) (Figure 2A-C) or simply emphasised nuclei (more or less of rhombic morphology), being common in the existence of limpid borders, either in planar-s or planar-e dolospirites. Ghosts of allochems and venules are relatively frequent (Figure 2B), as well as textures of mimetic and nonmimetic dedolomitization. Another abundant and relevant textural characteristic in these materials is the existence of styloliths (Figure 2D,E). Figure 2: **(A,B)** Hypidiotopic dolosparite mosaic. Replacive dolomite crystals show subrhombic cores (DOL-1) and rhombic-zoned cortex (DOL-2). **(C)** Detail of **(B)** micrograph. **(D,E)** Several phases of carbonate cements delineating fractures. Two generations of cements: dolomite cement (DC-1) and calcite cement (CC-1). Stylolite (blue arrows) and thinner calcite venules (black arrows) arranged parallel to the main carbonate vein can be observed. **(F,G)** Detail of **(E)** micrograph. **(A,D)** view in transmitted light. **(B,C,E,F)** view under cathodoluminescence. The dolostone facies have different contents in carbonate mineral phases (calcite and dolomite) (Table 2 and Table S1) and generally show very low content in other types of minerals (<5% in quartz, feldspar of clays) [7; 29; 31]. The 'crackle' breccias show the highest percentages of dolomite (85-90%). Mosaic and chaotic (rubble) breccias also have high contents of dolomite, but it must be considered that both matrix and cements, at least partially, may have a dolomitic composition. The matrix-supported types (rubble breccia) are the richest in calcite, reaching 45%. Both the calcite crystals associated with dolosparites, as well as those that make up venues and speleothems are LMC (<4% molMgCO\({}_{3}\)). The analysed dolomites are not stoichiometric and show an enrichment in Ca, with % molCaCO\({}_{3}\) values ranging from 50.3 to 56.1 (62% of samples between 53 and 55% molCaCO\({}_{3}\)). No relation between the stoichiometry of the dolomites, the dolomite textural types or the breccia fabric has been recognised. Regarding the degree of ordering of the dolomites, a direct relationship with their stoichiometry is not observed [7]. The main recognised breccia types show the same variability in the degree of ordering; it can only be noted that the dolosparitic mosaics associated with the 'crackle' breccias appear less ordered. XRF analysis corroborates that the studied dolomites are Ca-rich (geochemical data from Table S1--Supplementary Materials, [PERSON] et al. [7]). Si and Al contents are also low, indicating the scarce presence of silicate phases in the studied materials. Both Fe and Mn content are relatively low (Fe\({}_{2}\)O\({}_{3}\) between 0.1 and 0.42%; Mn below 100 ppm in most samples). Cl contents in dolosparites are relatively low (>250 ppm), although the dolomicrosparitic subtype shows a greater range of composition (100-450 ppm). On the contrary, Na concentration is relatively high (220-3100 ppm). Sr in the dolomitic phases varies between 132 and 268 ppm, presenting a good correlation with both Mg and Ca contents. However, no discrimination of the aforementioned groups (breccia types, dolomitic petrographic types) is observed in terms of Sr content. Calcite and dolomite cements show similar values in Fe content but significantly lower values in Si, Al, Na and K. As in dolomite clasts, the relatively high Sr values (175-610 ppm) also stand out.