Abstract Recent ichnological analysis conducted in two sections (Rodiles and Lastres) of the Asturian Basin revealed the presence of Halimedides Lorenz von Liburnau 1902 , which occurs just above the black shales related to the end of the Toarcian Oceanic Anoxic Event (T-OAE). Halimedides is associated with recovery of the trace-maker community after the re-establishment of favourable, oxic, conditions. The appearance of Halimedides after the T-OAE event, previously not registered, supports the close relationship of the trace maker with oxygen conditions, as occurs in other anoxic events including the Cretaceous OAE-1a and OAE-2. Also, a relationship between morphometric and palaeoenvironmental parameters is observed: occurring larger and densely chambered specimens in darker, weakly oxygenated facies, while smaller and sparsely chambered forms are registered in lighter, better oxygenated sediments.

Abstract In this paper, we present a detailed review of upper Pliensbachian–lower Toarcian kerogen assemblages from the southern areas of the West Tethys shelf (between Morocco and northern Spain) and demonstrate the use of the Phytoclast Group as a tracer of palaeoenvironmental changes in the early Toarcian. The kerogen assemblages in the studied sections from the southern areas of the West Tethys shelf are dominated by the Phytoclast Group and terrestrial palynomorphs, although punctual increases in amorphous organic matter, freshwater ( Botryococcus ) and marine microplankton (dinoflagellate cysts, acritarchs and prasinophyte algae) were observed at specific stratigraphic intervals. The opaque/non-opaque phytoclasts ratio was used to trace changes in palaeoclimate and other palaeoenvironmental parameters and reflect climate gradients associated with water availability during early Toarcian. During the Pliensbachian–Toarcian and Jenkyns events, changes in kerogen assemblages in the southern areas of the West Tethys shelf correlated with changes in the northern Tethys and Panthalassa shelf. The acceleration of the hydrological cycle associated with the aforementioned events was less intense in the northern Gondwana, southern and western Iberian basins, a reflection of the palaeogeographic position of these basins within the semi-arid climate belt when compared with the northern Iberian region and other northern areas of the West Tethys and Panthalassa shelf, inserted in winter-wet and warm temperate climate belts. Amorphous organic matter enrichment associated with the Pliensbachian–Toarcian and Jenkyns events reflects an increase in primary productivity linked with increased continental weathering, fluvial runoff and riverine organic matter, and nutrient input into marine areas, inducing water column stratification and promoting the preservation of organic matter.

Abstract This paper presents a summary of palynological data for Pennsylvanian age coal beds in the Appalachian Basin, discussed primarily from a biostratigraphic perspective. Coal bed palynofloras of Lower Pennsylvanian through early Permian age are compared and correlated with miospore assemblage zones established for western Europe, and the Eastern Interior (Illinois) and Western Interior Basins of the mid-continent USA. Lower Pennsylvanian palynofloras, which are dominated by lycopsid spores, are correlative with the Langsettian of western Europe and the Morrowan of the Eastern and Western Interior mid-continent USA Basins. Stratigraphically useful palynotaxa include Dictyotriletes bireticulatus , Radiizonates striatus , Schulzospora rara , Granasporites medius , Laevigatosporites minor and Endosporites globiformis . Middle Pennsylvanian palynofloras change through time, being lycopsid dominant in the lower part and more heterogeneous in the middle and upper parts with increased contributions from other Pennsylvanian plant groups. They are correlative with the Duckmantian, Bolsovian and Asturian of western Europe and the Atokan and Desmoinesian of the Eastern and Western Interior mid-continent USA Basins. Stratigraphically useful palynotaxa include Secarisporites remotus , Microreticulatisporites sulcatus , Vestispora fenestrata , Triquitrites sculptilis , Laevigatosporites globosus , Radiizonates difformis , Torispora securis , Triquitrites minutus , Mooreisporites inusitatus , Murospora kosankei , Thymospora pseudothiessenii and Schopfites dimorphus . Upper Pennsylvanian and lower Permian coal beds in the Appalachian Basin, in contrast to their Lower and Middle Pennsylvanian counterparts, are strongly dominated by tree fern spore palynotaxa. Palynofloras correlate with the Stephanian and Autunian of western Europe and the Missourian, Virgilian and Wolcampian of the Eastern and Western Interior mid-continent USA Basins.