# Barzalosa Formation

The Barzalosa Formation (Spanish: Formación Barzalosa, Pgb, Pgba) is a fossiliferous geological formation of the Upper Magdalena Valley and the bounding foothills of the Central Ranges and Eastern Ranges of the Colombian Andes. The formation consists of conglomerates, sandstones and siltstones. The Barzalosa Formation probably dates to the Late Paleogene to Early Neogene period; Oligocene to Early Miocene epochs, and has an approximate thickness of 360 metres (1,180 ft). Fossils of Balanerodus logimus, Lophiodolodus chaparralensis, Xenastrapotherium chaparralensis, Protheosodon sp. and Proadinotherium sp. have been uncovered from the formation in Chaparral, Tolima.

## Etymology

The formation was defined by Scheibe in 1934 and named after Barzalosa, a vereda of Girardot, Cundinamarca. Cáceres and Etayo elevated the "Pisos de Barzalosa" to a formation in 1969.

## Description
### Lithologies

The Barzalosa Formation consists of conglomerates, sandstones and siltstones. In parts, the formation contains shale beds and gypsum.

### Stratigraphy and depositional environment

The approximately 360 metres (1,180 ft) thick Barzalosa Formation overlies the Olini Group and the Seca Formation in the west and is overlain by the Honda Group. In the east towards Fusagasugá, the formation overlies the La Tabla Formation and is overlain by the Carmen de Apicalá Conglomerate. As the formation does not contain foraminifera, the age is difficult to establish, but has been estimated to be Oligocene to Early Miocene, or Middle Eocene to Oligocene. The depositional environment has been interpreted as alluvial fans and braided rivers.

### Fossil content

| Location | Department | Fossils |
| Alto San José, Chaparral | Tolima | Balanerodus logimus |
| Alto San José, Chaparral | Tolima | Lophiodolodus chaparralensis |
| Alto San José, Chaparral | Tolima | Xenastrapotherium chaparralensis |
| Alto San José, Chaparral | Tolima | Protheosodon sp. |
| Alto San José, Chaparral | Tolima | Proadinotherium sp. |
| Alto San José, Chaparral | Tolima | Megalonychoidae indet., Gavialidae indet. |

## Outcrops

The Barzalosa Formation is apart from its type locality found in Tocaima and to the east of Agua de Dios, and on the western side of the Magdalena River around Chaparral, Tolima.

## Regional correlations

Stratigraphy of the Llanos Basin and surrounding provinces :
| Ma | Age | Regional events | Catatumbo | Cordillera | proximal Llanos | distal Llanos | Putumayo | VSM | Environments | Maximum thickness | Petroleum geology | Notes |
| 0.01 | Holocene | Holocene volcanism Seismic activity | alluvium | alluvium | alluvium | alluvium | alluvium | alluvium | alluvium | | Overburden | |
| 1 | Pleistocene | Pleistocene volcanism Andean orogeny 3 Glaciations | Guayabo | Soatá Sabana | Necesidad | Guayabo | Gigante Neiva | Gigante Neiva | Alluvial to fluvial (Guayabo) | 550 m (1,800 ft) (Guayabo) | Overburden | |
| 2.6 | Pliocene | Pliocene volcanism Andean orogeny 3 GABI | Guayabo | Subachoque | Necesidad | Guayabo | Gigante Neiva | Gigante Neiva | Alluvial to fluvial (Guayabo) | 550 m (1,800 ft) (Guayabo) | Overburden | |
| 5.3 | Messinian | Andean orogeny 3 Foreland | Guayabo | Marichuela | Necesidad | Guayabo | Caimán | Honda | Alluvial to fluvial (Guayabo) | 550 m (1,800 ft) (Guayabo) | Overburden | |
| 13.5 | Langhian | Regional flooding | León | hiatus | Caja | León | Caimán | Honda | Lacustrine (León) | 400 m (1,300 ft) (León) | Seal | |
| 16.2 | Burdigalian | Miocene inundations Andean orogeny 2 | C1 | hiatus | Carbonera C1 | Carbonera C1 | Ospina | Honda | Proximal fluvio-deltaic (C1) | 850 m (2,790 ft) (Carbonera) | Reservoir | |
| 17.3 | Burdigalian | Miocene inundations Andean orogeny 2 | C2 | hiatus | Carbonera C2 | Carbonera C2 | Ospina | Honda | Distal lacustrine-deltaic (C2) | 850 m (2,790 ft) (Carbonera) | Seal | |
| 19 | Burdigalian | Miocene inundations Andean orogeny 2 | C3 | hiatus | Carbonera C3 | Carbonera C3 | Ospina | Honda | Proximal fluvio-deltaic (C3) | 850 m (2,790 ft) (Carbonera) | Reservoir | |
| 21 | Early Miocene | Pebas wetlands | C4 | hiatus | Carbonera C4 | Carbonera C4 | Ospina | Barzalosa | Distal fluvio-deltaic (C4) | 850 m (2,790 ft) (Carbonera) | Seal | |
| 23 | Late Oligocene | Andean orogeny 1 Foredeep | C5 | hiatus | Carbonera C5 | Carbonera C5 | Orito | Orito | Proximal fluvio-deltaic (C5) | 850 m (2,790 ft) (Carbonera) | Reservoir | |
| 25 | Late Oligocene | Andean orogeny 1 Foredeep | C6 | hiatus | Carbonera C6 | Carbonera C6 | Orito | Orito | Distal fluvio-lacustrine (C6) | 850 m (2,790 ft) (Carbonera) | Seal | |
| 28 | Early Oligocene | Andean orogeny 1 Foredeep | C7 | hiatus | C7 | | Pepino | Gualanday | Proximal deltaic-marine (C7) | 850 m (2,790 ft) (Carbonera) | Reservoir | |
| 32 | Oligo-Eocene | Andean orogeny 1 Foredeep | C8 | Usme | C8 | onlap | Pepino | Gualanday | Marine-deltaic (C8) | 850 m (2,790 ft) (Carbonera) | Seal Source | |
| 35 | Late Eocene | Andean orogeny 1 Foredeep | Mirador | Usme | Mirador | Mirador | Pepino | Gualanday | Coastal (Mirador) | 240 m (790 ft) (Mirador) | Reservoir | |
| 40 | Middle Eocene | Andean orogeny 1 Foredeep | Mirador | Regadera | Mirador | Mirador | Pepino | hiatus | Coastal (Mirador) | 240 m (790 ft) (Mirador) | Reservoir | |
| 45 | Middle Eocene | Andean orogeny 1 Foredeep | Mirador | Regadera | Mirador | Mirador | Pepino | hiatus | Coastal (Mirador) | 240 m (790 ft) (Mirador) | Reservoir | |
| 50 | Early Eocene | Andean orogeny 1 Foredeep | Socha | Regadera | Los Cuervos | Los Cuervos | Pepino | hiatus | Deltaic (Los Cuervos) | 260 m (850 ft) (Los Cuervos) | Seal Source | |
| 55 | Late Paleocene | PETM 2000 ppm CO$_2$ | Los Cuervos | Bogotá | Los Cuervos | Los Cuervos | Pepino | Gualanday | Deltaic (Los Cuervos) | 260 m (850 ft) (Los Cuervos) | Seal Source | |
| 60 | Early Paleocene | SALMA | Barco | Guaduas | Barco | Barco | Rumiyaco | Gualanday | Fluvial (Barco) | 225 m (738 ft) (Barco) | Reservoir | |
| 65 | Maastrichtian | KT extinction | Catatumbo | Guadalupe | Guadalupe | Guadalupe | Rumiyaco | Monserrate | Deltaic-fluvial (Guadalupe) | 750 m (2,460 ft) (Guadalupe) | Reservoir | |
| 72 | Campanian | End of rifting | Colón-Mito Juan | Guadalupe | Guadalupe | Guadalupe | Rumiyaco | Monserrate | Deltaic-fluvial (Guadalupe) | 750 m (2,460 ft) (Guadalupe) | Reservoir | |
| 83 | Santonian | End of rifting | Colón-Mito Juan | Guadalupe | Guadalupe | Guadalupe | Villeta/Güagüaquí | Villeta/Güagüaquí | Deltaic-fluvial (Guadalupe) | 750 m (2,460 ft) (Guadalupe) | Reservoir | |
| 86 | Coniacian | End of rifting | Colón-Mito Juan | Guadalupe | Guadalupe | Guadalupe | Villeta/Güagüaquí | Villeta/Güagüaquí | Deltaic-fluvial (Guadalupe) | 750 m (2,460 ft) (Guadalupe) | Reservoir | |
| 89 | Turonian | Cenomanian-Turonian anoxic event | La Luna | Chipaque | Gachetá | hiatus | Villeta/Güagüaquí | Villeta/Güagüaquí | Restricted marine (all) | 500 m (1,600 ft) (Gachetá) | Source | |
| 93 | Cenomanian | Rift 2 | La Luna | Chipaque | Gachetá | hiatus | Villeta/Güagüaquí | Villeta/Güagüaquí | Restricted marine (all) | 500 m (1,600 ft) (Gachetá) | Source | |
| 100 | Albian | Rift 2 | La Luna | Une | Une | hiatus | Caballos | Caballos | Deltaic (Une) | 500 m (1,600 ft) (Une) | Reservoir | |
| 113 | Aptian | Rift 2 | Capacho | Fómeque | Une | hiatus | Motema | Yaví | Open marine (Fómeque) | 800 m (2,600 ft) (Fómeque) | Source (Fóm) | |
| 125 | Barremian | High biodiversity | Aguardiente | Paja | Une | hiatus | Motema | Yaví | Shallow to open marine (Paja) | 940 m (3,080 ft) (Paja) | Reservoir | |
| 129 | Hauterivian | Rift 1 | Tibú- Mercedes | Las Juntas | hiatus | hiatus | Motema | Yaví | Deltaic (Las Juntas) | 910 m (2,990 ft) (Las Juntas) | Reservoir (LJun) | |
| 133 | Valanginian | Rift 1 | Río Negro | Cáqueza Macanal Rosablanca | hiatus | hiatus | Motema | Yaví | Restricted marine (Macanal) | 2,935 m (9,629 ft) (Macanal) | Source (Mac) | |
| 140 | Berriasian | Rift 1 | Girón | Cáqueza Macanal Rosablanca | hiatus | hiatus | Motema | Yaví | Restricted marine (Macanal) | 2,935 m (9,629 ft) (Macanal) | Source (Mac) | |
| 145 | Tithonian | Break-up of Pangea | Jordán | Arcabuco | Buenavista Batá | hiatus | Saldaña | Saldaña | Alluvial, fluvial (Buenavista) | 110 m (360 ft) (Buenavista) | "Jurassic" | |
| 150 | Early-Mid Jurassic | Passive margin 2 | La Quinta | Montebel Noreán | hiatus | hiatus | Saldaña | Saldaña | Coastal tuff (La Quinta) | 100 m (330 ft) (La Quinta) | "Jurassic" | |
| 201 | Late Triassic | Passive margin 2 | Mucuchachi | Montebel Noreán | hiatus | hiatus | Payandé | Payandé | | | "Jurassic" | |
| 235 | Early Triassic | Pangea | | hiatus | hiatus | hiatus | | | | | "Paleozoic" | |
| 250 | Permian | Pangea | | hiatus | hiatus | hiatus | | | | | "Paleozoic" | |
| 300 | Late Carboniferous | Famatinian orogeny | | hiatus | hiatus | hiatus | | Cerro Neiva | | | "Paleozoic" | |
| 340 | Early Carboniferous | Fossil fish Romer's gap | | Cuche (355-385) | Farallones | hiatus | | Cerro Neiva | | Deltaic, estuarine (Cuche) | "Paleozoic" | 900 m (3,000 ft) (Cuche) |
| 360 | Late Devonian | Passive margin 1 | Río Cachirí (360-419) | Cuche (355-385) | Farallones | | | Ambicá | Alluvial-fluvial-reef (Farallones) | 2,400 m (7,900 ft) (Farallones) | "Paleozoic" | |
| 390 | Early Devonian | High biodiversity | Floresta (387-400) El Tíbet | Floresta (387-400) El Tíbet | | | | Ambicá | Shallow marine (Floresta) | 600 m (2,000 ft) (Floresta) | "Paleozoic" | |
| 410 | Late Silurian | Silurian mystery | Floresta (387-400) El Tíbet | Floresta (387-400) El Tíbet | | | | | | | "Paleozoic" | |
| 425 | Early Silurian | Silurian mystery | hiatus | hiatus | hiatus | hiatus | hiatus | hiatus | | | "Paleozoic" | |
| 440 | Late Ordovician | Rich fauna in Bolivia | San Pedro (450-490) | | Duda | | | | | | "Paleozoic" | |
| 470 | Early Ordovician | First fossils | San Pedro (450-490) | Busbanzá (>470±22) ChuscalesOtengá | Guape | | Río Nevado | HígadoAgua Blanca Venado (470-475) | | | "Paleozoic" | |
| 488 | Late Cambrian | Regional intrusions | Chicamocha (490-515) | Quetame | Ariarí | | SJ del Guaviare (490-590) | San Isidro | | | "Paleozoic" | |
| 515 | Early Cambrian | Cambrian explosion | | Quetame | | | SJ del Guaviare (490-590) | San Isidro | | | "Paleozoic" | |
| 542 | Ediacaran | Break-up of Rodinia | | pre-Quetame | | post-Parguaza | SJ del Guaviare (490-590) | El Barro | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 600 | Neoproterozoic | Cariri Velhos orogeny | Bucaramanga (600-1400) | pre-Quetame | | post-Parguaza | pre-Guaviare | El Barro | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 800 | Neoproterozoic | Snowball Earth | Bucaramanga (600-1400) | pre-Quetame | | post-Parguaza | pre-Guaviare | El Barro | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1000 | Mesoproterozoic | Sunsás orogeny | Bucaramanga (600-1400) | pre-Quetame | Ariarí (1000) | post-Parguaza | pre-Guaviare | La Urraca (1030-1100) | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1300 | Mesoproterozoic | Rondônia-Juruá orogeny | Bucaramanga (600-1400) | pre-Quetame | pre-Ariarí | Parguaza (1300-1400) | pre-Guaviare | Garzón (1180-1550) | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1400 | Mesoproterozoic | Rondônia-Juruá orogeny | pre-Bucaramanga | pre-Quetame | pre-Ariarí | | pre-Guaviare | Garzón (1180-1550) | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1600 | Paleoproterozoic | Rondônia-Juruá orogeny | pre-Bucaramanga | pre-Quetame | pre-Ariarí | Maimachi (1500-1700) | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1800 | Paleoproterozoic | Tapajós orogeny | pre-Bucaramanga | pre-Quetame | pre-Ariarí | Mitú (1800) | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 1950 | Paleoproterozoic | Transamazonic orogeny | pre-Bucaramanga | pre-Quetame | pre-Ariarí | pre-Mitú | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 2200 | Paleoproterozoic | Columbia | pre-Bucaramanga | pre-Quetame | pre-Ariarí | pre-Mitú | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 2530 | Archean | Carajas-Imataca orogeny | pre-Bucaramanga | pre-Quetame | pre-Ariarí | pre-Mitú | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| 3100 | Archean | Kenorland | pre-Bucaramanga | pre-Quetame | pre-Ariarí | pre-Mitú | pre-Guaviare | pre-Garzón | Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province) | | Basement | |
| Sources ||||||||||||||

### Legend

* group
* important formation
* fossiliferous formation
* minor formation
* (age in Ma)
* proximal Llanos (Medina)
* distal Llanos (Saltarin 1A well)