Figure - available via license: Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
Content may be subject to copyright.
Source publication
The present study discusses the outcome of palynlogical and palaeobotanocal investigations of Middle Jurassic strata of the Tabas Block. The most commonly identified spore type is a trilete spore, Klukisporites, which accounts for 30 per cent, and the genus Ischyosporites which makes up 12 per cent of the spore collection. Plant fossils recovered f...
Citations
... This association suggests that Alisporites has existed in drier lowland environments (e.g. Costamagna et al., 2017), consistent with the known habitats of the Corystospermales (Maleki, 2024). The parental plants of Alisporites, Umkomasiaceae (=Corystospermaceae), would have been large shrubs, forming mangrove thickets along tidally flooded river mouths (Abbink et al., 2004), which is also links with the proposal of Barrón et al. (2010) that Alisporites has a hygrophilous character. ...
The Los Molles Formation (Early–Middle Jurassic) in the Picún Leufú Sub-basin, Neuquén Basin, Argentina, is a clastic unit accumulated in a marine-delta system. Its deposits are rich in organic matter, and provide a detailed record for palaeoenvironmental reconstruction. The present contribution integrates sedimentological and palynological data from the Painemilla section (0-100 m interval) to infer palaeoenvironmental, palaeoecological, and palaeoclimatic conditions. The palaeoenvironment evolved from a hyperpycnal littoral delta during wetter periods to a marine littoral delta system during drier ones. The five identified palynofacies-types show a high terrestrial input due to the predominance of phytoclasts. PT-1, 2 and 5 are associated with light hyperpycnites, while PT-3 and 4 characterise offshore/prodelta deposits. Sporomorph assemblages dominated by Hirmeriellaceae and Araucariaceae are consistent with a seasonally dry (winterwet) biome. The highest values of Araucariaceae show a good correlation with the parasequences, representing the maximum water input into the basin. The Callialasporites complex record suggests an age no older than late Toarcian. A Sporomorph Ecogroup (SEG) analysis is applied for the first time in the Los Molles Formation. Principal Components Analysis points to variations in palaeoecology and the taphonomic component in the record (water/wind-transport taxa). This analysis reveals an active participation of the Coastal (Hirmeriellaceae), Lowland (Araucariaceae and Umkomasiaceae) and Riverside (Caytoniaceae) SEGs throughout the entire section, showing an increase in the Upland SEG supply towards the upper part of the section. This study highlights the role of light hyperpycnal flows in the sedimentary and palynological records, providing new insights into Jurassic palaeoenvironmental and ecological dynamics in the Neuquén Basin.
