Mesón Group

Mesón Group (Spanish: Grupo Mesón) is a Cambrian to Early Ordovician sedimentary formation located in the Argentine Northwest and nearby parts of Bolivia. The group members rest unconformably on top of the Ediacaran–Cambrian Puncoviscana Formation. According to G.F. Aceñolaza, the Mesón Basin – the sedimentary basin in which the Méson Group was deposited – was located between the Arequipa and Río de la Plata Cratons.[1]

Mesón Group Stratigraphic range: Cambrian-Tremadocian
Type	Group
Sub-units	Lizoite Fm. Campanario Fm. Chahualmayoc Fm.
Underlies	Santa Victoria Group
Overlies	Puncoviscana Formation
Lithology
Primary	Sandstone, siltstone, limestone
Location
Coordinates	23.0°S 65.0°W
Approximate paleocoordinates	45.4°S 128.9°W
Region	Jujuy, Salta, Tucumán Potosí Department
Country	Argentina  Bolivia
Mesón Group (Argentina)

Stratigraphy

The Mesón Group comprises three formations: Chahualmayoc Formation at the top, Lizoite Formation at the base and Campanario Formation in-between.[2] The group is composed of sandstones, siltstones and limestones.[3][4]

Fossil content

The group has provided fossils of:

Trilobites

• Asaphellus sp.
• Notopeltis sp.

Other

• Macrocystella sp.

References

1. Aceñolaza, G.F. (2003). "The Cambrian System in Northwestern Argentina: stratigraphical and palaeontological framework". Geologica Acta. 1 (1): 23–39. Retrieved 28 December 2015.
2. Mángano, M. G., & Buatois, L. A. (2000). Ichnology, sedimentary dynamics, and sequence stratigraphy of the Mesón Group: A Cambrian macrotidal shallow-marine depositional system in northwest Argentina. Cambrian from the southern edge, Instituto Superior de Correlación Geológica, Miscelánea, 6, 109–110.
3. Grupo Meson Quartzite Fm., Alto de la sierra, Argentina at Fossilworks.org
4. Grupo Meson Quartzite Fm., Sapagua (Humamuaco), Argentina at Fossilworks.org

Further reading

• F. G. Acenolaza. 1986. El genero Macrocystella (Cystoidea) en el Tremadociano de Salta y Jujuy. Actas del IV congreso Argentino de paleontologia y bioestratigrafia - Simposio: Bioestratigrafia del Paleozoico Inferior. Ed. A. Cuerda. 1:133-137