Navidad Formation
| Navidad Formation Stratigraphic range: Early-Mid Miocene |
|
|---|---|
| Type | Geological formation |
| Underlies | Licancheu Formation |
| Overlies | Paleozoic granitic basement Punta Tocopalma Formation |
| Thickness | Up to 100–200 m |
| Lithology | |
| Primary | Sandstone, siltstone, conglomerate |
| Other | Coquina |
| Location | |
| Region |
Valparaíso Region O'Higgins Region |
| Country | Chile |
| Type section | |
| Named for | Navidad |
Navidad Formation (Spanish: Formación Navidad) is a marine Neogene sedimentary formation located in Central Chile. The formation is known for its diverse and abundant fossil record and is considered the reference unit for the marine Neogene in Chile. Originally described by Charles Darwin in 1846 the formation has attracted the attention of numerous prominent geologists and paleontologists since then. As a key formation Navidad has been subject to a series of differing interpretations and scientific disputes over time.
Charles Darwin saw the formation in September 1834 during the second voyage of HMS Beagle. He became the first to describe it 1846 when he published his book Geological Observations on South America in 1846 and it was named by Darwin after the nearby town of Navidad. In this book Darwin calls the formation "Formation of Navidad" and "Sandstone Formation at Navidad". There are no signs of that Darwin would have attempted to make a formal definition of the formation.
...the next point at which I landed was at Navidad, 160 miles north of Concepcion, and 60 miles south of Valparaiso. The cliffs here are about 800 feet in height : they consist, wherever I could examine them, of fine-grained, yellowish, earthy sandstones, with ferruginous veins, and with concretions of hard calcareous sandstone. [...] The sandstone contains fragments of wood, either in the state of lignite or partially silicified, shark's teeth, and shells in great abundance...
Early fossil descriptions from Navidad Formation were those of George Sowerby in Geological Observations on South America (1846) and by Rodolfo Amando Philippi (1887).
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Wikipedia