Oncoidal-ooidal intraclastic grainstone (oiG) |
Dark grey, massive, laminated, with wave ripple or HCS, laminations and cross stratifications. Lenticular or tabular geometry. Micritized micro-oncoids, oncoids and ooids are present. Cm- to m-thick. |
Fine grained (0,076 to 0,32 mm), fine blocky calcite cement (20-70%), ooids/peloids (30-65%), angular to subrounded intraclasts (< 40%), quartz (5-10%) and 1% average of opaque minerals. Some mica can be present. Peloids/ooids and micritized micro-oncoid are 0,14 to 0,35 mm and commonly subrounded to rounded, occasionally presenting “ghosts” of concentric structure. Plane parallel lamination. Micritization and pyritization processes. |
Oscillatory or combined flows with high to low energy. |
Storm events in mid to outer ramp. |
Intraclastic grainstone (iG) |
Dark grey, massive, laminated, with wave ripple or HCS, laminations and cross stratifications. Lenticular or tabular geometry. Intraclasts are the main component. Cm- to m-thick. |
Commonly laminated, grain size between silt and medium sand (0,028 - 0,35 mm). In general, 40-70% blocky calcite cement content, 10-50% of mudstone intraclasts. Intraclasts are up to 2 mm, angular to subangular, sometimes with elongated shape. Micas are present (< 5%). Ooids and micro-oncoids are rare, poorly preserved. |
Oscillatory or combined flows with high to low energy. |
Storm events in mid to outer ramp. |
Breccia (B) |
Intraclasts of mudstone with diverse sizes and shapes oriented or chaotically distributed in a carbonatic matrix. Sharp contact or erosive base. Mainly lenticular geometry. |
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Erosive process. Turbulent and high energy flow. |
Storm events in mid to outer ramp. |
Wackestone with siliciclastic (W) |
Fine, light grey, generally massive, eventually laminated. Intraclasts and siliciclastic grains may be present (< 15%). |
Silt to fine grained carbonate with siliciclastic grains. Generally laminated. Carbonate matrix (50-70%), angular to subangular quartz grains (15-50%), mudstone intraclasts (< 15%), opaques (< 15%), white micas (< 5%), rarely clay minerals and feldspar. |
Suspension, low energy. |
Deposition by suspension and precipitation in protected area or outer ramp. |
Mudstone (Ms) |
Fine, massive to poorly laminated, rare siliciclastic content (< 10%). Syneresis cracks. |
Carbonate rock with 5-10% of siliciclastic content (grains of quartz, mica and opaque minerals). |
Suspension, low energy. |
Deep marine, outer ramp. |
Oncoidal-pisoidal rudstone (r) |
Dark grey. Oncoids and pisoids with intraclasts. Tabular cross-stratification. Lenticular geometry. |
Oncoids, pisoids, ooids, rare intraclasts, sparry calcite cement predominates. |
Unidirectional tractive flow, moderate to low energy. |
Sand bars in inner ramp. |
Siltstone (st) |
Dark grey, massive or plane parallel lamination. |
Medium to coarse silt (0,034 - 0,056 mm), laminated. Composed mainly of angular to subangular quartz grain (50-85%), surrounded by carbonate cement, oriented mica, cloritized clay matrix and disperse opaque (5-10%). Few carbonate matrix (< 20%) |
Low energy, suspension |
Deep marine, outer ramp to basin. |
Mudrock (m) |
Massive, brown. Fine laminated, with tabular geometry. Cm- to mm-thick beds. |
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Suspension, low energy. |
Deep marine sedimentation, outer ramp to basin. |
Sandstone (s) |
Fine, light brown, massive. |
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High-energy tractive flow |
Shoreface to foreshore (?) |