Academic Journal

Shell bed stacking patterns in the Chachao formation (Early Valanginian) in Malargüe area, Mendoza Province, Neuquen Basin-Argentina

التفاصيل البيبلوغرافية
العنوان: Shell bed stacking patterns in the Chachao formation (Early Valanginian) in Malargüe area, Mendoza Province, Neuquen Basin-Argentina
المؤلفون: Palma, Ricardo Manuel, Lanés, Silvia G.
بيانات النشر: Springer
المجموعة: CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas)
مصطلحات موضوعية: Shell beds, Chachao Formation, Valanginian, Neuquen Basin, https://purl.org/becyt/ford/1.5, https://purl.org/becyt/ford/1
الوصف: The Lower Cretaceous Chachao Formation in the Malargüe anticline area consists of wackestone, packstone, and minor grainstone and mudstone rich in benthic fauna which were deposited in a shallow carbonate ramp. These shell beds are composed of a low-diversity molluscan fauna mostly dominated by oysters, other benthic pelecypods (Eryphila sp., Ptychomya sp., Pecten sp., Pinna sp., Trigonia sp., Cucullaea sp.), serpulids (Sarcinella sp., Parsimonia sp.), and occasional ammonites (Olcosthepanus curacoensis). Most skeletal accumulations range from 15 to 70 cm in thickness. Shell beds exhibit a sharp, flat and commonly undulating base. In some cases the tops were bioturbated principally by Thalassinoides isp. Some shell beds show a densely packed biofabric (bioclastic-supported) but most of them have dispersed or loosely packed biofabric (mud-supported). Bioclasts include articulated or disarticulated shells, fragmented valves and shell debris. The analysis of shell concentrations of the Chachao Formation allow to recognize four taphofacies according to their taphonomic attributes. Different kind of processes, such as low-energy storm currents and waves, were interpreted, whose deposits are arranged into a coarsening- and thickening-upward and then fining- and thinning upward trends. According to their biostratinomic features shell beds of Chachao Formation have been interpreted as parautochthonous to autochthonous skeletal concentrations, mainly of sedimentologic origin. Towards the end of the Valanginian, the drowning of the carbonate ramp took place, related to a relative sea level rise and environmental stress. This drowning event was recorded by the alternating thin- to medium bedded dark gray carbonate and black shales (Agrio Formation) of Late Valanginian-Late Hauterivian age. ; Fil: Palma, Ricardo Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. ...
نوع الوثيقة: article in journal/newspaper
وصف الملف: application/pdf
اللغة: English
تدمد: 0891-2556
Relation: info:eu-repo/semantics/altIdentifier/url/https://link.springer.com/article/10.1007%2FBF03175834; http://hdl.handle.net/11336/93826; Palma, Ricardo Manuel; Lanés, Silvia G.; Shell bed stacking patterns in the Chachao formation (Early Valanginian) in Malargüe area, Mendoza Province, Neuquen Basin-Argentina; Springer; Carbonates And Evaporites; 16; 2; 12-2001; 168-180; CONICET Digital; CONICET
الاتاحة: http://hdl.handle.net/11336/93826
Rights: info:eu-repo/semantics/openAccess ; https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
رقم الانضمام: edsbas.10FA9BC
قاعدة البيانات: BASE