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Microflora de la Formación Panguipulli (Triásico Superior), en Licán Ray, Lago Calafquén, 10º Región, Chile

2003; Asociación Paleontológica Argentina; Volume: 40; Issue: 4 Linguagem: Espanhol

1851-8044

Ana Marı́a Zavattieri, Rafael Herbst, Jorge Muñoz Bravo,

Geology and Paleoclimatology Research

Resumen. En la localidad de Lican Ray, en la ribera norte del lago Calafquen (39o 30’ S - 72o 12’ W), 10o Region de Chile, se hallo en un unico nivel de la Formacion Panguipulli, una asociacion microfloristica de origen continental, moderadamente bien preservada. La secuencia sedimentaria representa un sistema deltaico lacustre. Esta asociacion incluye 17 especies de esporas de briofitas y pteridofitas asignadas a los generos Apiculatisporis, Aratrisporites, Baculatisporites, Cacheutasporites, Calamospora, Deltoidospora, Dictyophyllidites, Gleicheniidites, Neoraistrickia, Osmundacidites, Punctatisporites y Rogalskaisporites, las cuales representan casi el 17% del total de la asociacion. Los granos de polen de diversas gimnospermas dominan ampliamente la microflora, correspondiendo al 81,9%, e incluyen 26 especies de los generos Accinctisporites, Alisporites, Chordasporites, Cuneatisporites, Cycadopites, Equisetosporites, Falcisporites, Goubinispora, Inaperturopollenites, Klausipollenites, Lunatisporites, Minutosaccus, Platysaccus, Podocarpidites, Protodiploxypinus, Sulcatisporites, Sulcosaccispora y Vesicaspora. La microflora esta asociada con una megaflora integrada por especies de los generos Dicroidium, Cladophlebis, Gleichenites, Linguifolium, Pseudoctenis y Sphenobaiera, entre otros. Esta asociacion microfloristica difiere parcialmente, en su composicion, de la unica otra microflora hallada previamente en Chile proveniente de la Formacion Llafquentue-Huimpil; ambas se asignan al Triasico Superior Temprano por comparacion con microfloras equivalentes de Argentina, que corresponden a la Microflora Ipswich de las provincias microfloristias gondwanicas. Como tal, la microflora de Panguipulli representa comunidades vegetales de clima templado a templado-calido con marcada estacionalidad y en general humedo localmente. Abstract. MICROFLORA OF THE PANGUIPULLI FORMATION (UPPER TRIASSIC) AT LICAN RAY, LAKE CALAFQUEN, 10TH REGION, CHILE. Triassic continental sedimentary sequences from several localities of central Chile were sampled for palynological study. A moderately well preserved continental assemblage in one sample from Panguipulli Formation, at Lican Ray, north of Lake Calafquen (39o 30’ S - 72o 12’ W), 10o Region of Chile is recorded. The sequence represents a deltaiclacustrine environment of deposition. The Panguipulli assemblage is composed of 17 species of bryophytic and pteridophytic spores assigned to the genera Apiculatisporis, Aratrisporites, Baculatisporites, Cacheutasporites, Calamospora, Deltoidospora, Dictyophyllidites, Gleicheniidites, Neoraistrickia, Osmundacidites, Punctatisporites and Rogalskaisporites representing almost 17% of the total assemblage. Diverse gimnospermous pollen grains dominate the microflora with 81.9 % including 26 species of the genera Accinctisporites, Alisporites, Chordasporites, Cuneatisporites, Cycadopites, Equisetosporites, Falcisporites, Goubinispora, Inaperturopollenites, Klausipollenites, Lunatisporites, Minutosaccus, Platysaccus, Podocarpidites, Protodiploxypinus, Sulcatisporites, Sulcosaccispora and Vesicaspora. The microflora is associated with a megaflora composed of species of the genera Dicroidium, Cladophlebis, Gleichenites, Linguifolium, Pseudoctenis and Sphenobaiera, among others. This microfloristic assemblage differs partially from the only other Triassic microflora previously recorded in Chile from the Llafquentue-Huimpil Formation. Comparison with Argentine and other Gondwanic microfloras, favours an early Late Triassic age for the Paguipulli Formation which corresponds to the Ipswich Microflora of the gondwanic microfloristic provinces. Therefore, the Panguipulli microflora represents floral communities of temperate to warm-temperate climate, highly seasonal, points to a local and moistly environment.