Loading AI tools
From Wikipedia, the free encyclopedia
The Tunjuelo Formation, Río Tunjuelo or Río Tunjuelito Formation (Spanish: Formación Tunjuelo, Q1tu, Qpt, Qcc) is a geological formation of the Bogotá savanna, Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists mainly of conglomerates with intercalating shales and sandstones. The Tunjuelo Formation dates to the Quaternary period; covering the complete Pleistocene epoch, and has a maximum thickness of 150 metres (490 ft). It is a formation of the lacustrine and fluvio-glacial sediments of Lake Humboldt.
| Tunjuelo Formation | |
|---|---|
| Stratigraphic range: Pleistocene ~ | |
| Type | Geological formation |
| Underlies | Chía Fm., Sabana Fm. |
| Overlies | Marichuela Formation Subachoque Formation |
| Thickness | up to 150 metres (490 ft) |
| Lithology | |
| Primary | Conglomerate |
| Other | Sandstone, shale |
| Location | |
| Coordinates | 4°28′04.0″N 74°08′11.9″W |
| Region | Bogotá savanna, Altiplano Cundiboyacense Eastern Ranges, Andes |
| Country |  Colombia |
| Type section | |
| Named for | Tunjuelo River |
| Named by | Helmens & Hammen |
| Location | Tunjuelo River valley |
| Year defined | 1995 |
| Coordinates | 4°28′04.0″N 74°08′11.9″W |
| Region | Cundinamarca |
| Country | Colombia |
Paleogeography of the Pleistocene by Ron Blakey | |
The formation was first defined and named by Helmens and Van der Hammen in 1995 after the Tunjuelo River, also called Tunjuelito River, of southern Bogotá.[1]
The Tunjuelo Formation consists mainly of conglomerates with intercalating shales and sandstones.[1]
The Tunjuelo Formation conformably overlies the Marichuela Formation and in other parts the Subachoque Formation. The Tunjuelo Formation is overlain by the thin Chía Formation. The age has been estimated to be Pleistocene based on palynology and radiocarbon dating, covering the Pleistocene from 2.6 to 0.01 Ma.[2] The depositional environment has been interpreted as fluvio-glacial terraces.[1]
The Tunjuelo Formation is found at its type locality in the Tunjuelo River valley, in the synclinal of Guasca, near Cogua, Cundinamarca,[1] and in the basins of the rivers San Cristóbal, San Francisco, Arzobispo and Subachoque, and the creeks (quebradas) Las Delicias, La Vieja, Rosales and Chicó of the Colombian capital.[3] In the Tunjuelo River valley, the formation is crossed by the northeast–southwest oriented Yerbabuena Fault.[4]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.
