| Macarao Formation | |
| Period: | Priabonian |
| Age: | Mid-Late Eocene ~ |
| Type: | Geological formation |
| Prilithology: | Calcareous sandstone |
| Otherlithology: | Siltstone, gypsum |
| Unitof: | Cocinetas Basin |
| Underlies: | Castilletes Fm., Siamaná Fm. |
| Overlies: | Guaralamai Fm. Jarara Schist (basement) |
| Thickness: | 253m (830feet) |
| Coordinates: | 11.8333°N -71.4128°W |
| Region: | La Guajira Caribbean region |
| Namedby: | Rollins |
| Year Ts: | 1965 |
| Location Ts: | Uribia |
| Coordinates Ts: | 11.8333°N -71.4128°W |
| Region Ts: | La Guajira |
The Macarao Formation (Spanish; Castilian: Formación Macarao, E2m) is a geological formation of the Cocinetas Basin in the northernmost Colombian department of La Guajira. The formation consists of foraminifera-rich fine to medium grained calcareous sandstones intercalated with calcareous siltstones, cross-cut by veins of gypsum. The 253m (830feet) thick Macarao Formation dates to the Paleogene period; Middle to Late Eocene epoch, corresponding to the Divisaderan in the South American land mammal ages (SALMA).
The formation was defined by Rollins in 1965.[1]
The Macarao Formation consists of foraminifera-rich fine to medium grained calcareous sandstones intercalated with calcareous siltstones, cross-cut by veins of gypsum.[2]
The Macarao Formation has a maximum thickness of 253m (830feet) and overlies the Cretaceous Guaramalai Formation and the basement (Jarara Schist) and is overlain by the Siamaná and Castilletes Formations with a high angle unconformity. The age has been estimated to be Middle to Late Eocene, corresponding to the Divisaderan in the South American land mammal ages (SALMA). The formation has been deposited in a shallow marine bay environment.[3]
The Macarao Formation is a reservoir rock formation in the Guajira Basin.[4]
Geology of the Eastern Hills
Chota, Loreto, Regadera, Soncco, Usme Formations