The Joggins Fossil Cliffs UNESCO World Heritage site: a review of recent research

Abstract

The Joggins Fossil Cliffs UNESCO World Heritage Site is a Carboniferous coastal section along the shores of the Cumberland Basin, an extension of Chignecto Bay, itself an arm of the Bay of Fundy, with excellent preservation of biota preserved in their environmental context. The Cliffs provide insight into the Late Carboniferous (Pennsylvanian) world, the most important interval in Earth's past for the formation of coal. The site has had a long history of scientific research and, while there have been well over 100 publications in over 150 years of research at the Cliffs, discoveries continue and critical questions remain. Recent research (post-1950) falls under one of three categories: general geology; paleobiology; paleoecology. It provides a context for future work at the site. While recent research has made large strides in our understanding of the Late Carboniferous, many questions remain to be studied and resolved, and interest in addressing these issues is clearly not waning. Within the World Heritage Site, we suggest that the uppermost formations (Springhill Mines and Ragged Reef), paleosols, floral and trace fossil taxonomy, and microevolutionary patterns are among the most promising areas for future study. RÉSUMÉLe site du patrimoine mondial de l'UNESCO des falaises fossilifères de Joggins est situé sur une partie du littoral qui date du Carbonifère, sur les rives du bassin de Cumberland, qui est une prolongation de la baie de Chignecto, elle-même un bras de la baie de Fundy. L'endroit offre un excellent milieu de préservation de la faune et de la flore dans leur environnement. Les falaises donnent un aperçu du monde du Carbonifère tardif (Pennsylvanien), soit la période de l'histoire de la terre la plus importante pour la formation du charbon. Ces falaises ont fait depuis longtemps l'objet de travaux de recherche scientifique et plus de 100 publications y ont été consacrées au cours de 150 années de recherche. L'endroit suscite encore des découvertes et il soulève toujours des questions essentielles. Les travaux de recherche récents (depuis les années 1950) se répartissent en trois catégories: géologie générale; paléobiologie; et reconstitution des paléomilieux, en plus d'offrir des avenues pour les futurs travaux qui devraient s'y dérouler. Même si la recherche récente a largement contribué à une meilleure compréhension du Carbonifère tardif, de nombreuses questions demeurent sans réponse et commandent qu'on les étudie et les résolve et il est manifeste que l'intérêt pour ces questions est bien loin de s'amenuiser. Sur ce site du patrimoine mondial, nous soutenons que les futurs sujets d'étude les plus prometteurs seraient les formations supérieures (Springhill Mines et Ragged Reef), les paléosols, la taxonomie florale et des ichnofossiles, ainsi que les paramètres de microévolution.[Traduit par la redaction]

Constraints on the timescale of animal evolutionary history

“…Two unnamed possible crown caecilians are an unnamed form from the Wadi Milk Formation of Sudan (Cenomanian) and a terminal Cretaceous fossil from the Pajcha Pata in Bolivia. These provide hints that older caecilians, whose fossils appear to be so immensely rare, might be found down to the base of the Cretaceous at least, dated as 145.0 Ma ± 0.8 Myr (Gradstein et al, 2012, p. 838) (Carroll, 1964), and it falls within Eureptilia, on the stem to Diapsida (Laurin and Reisz, 1995;deBraga and Rieppel, 1997) -Lang et al, 2006;Grey and Fink, 2010;Utting et al, 2010) confirm that the Joggins Formation falls entirely within the Langsettian European time unit, equivalent to the Westphalian A, and roughly matching the Russian Cheremshanian, in the later part of the Bashkirian Stage. Earlier dates for these units were equivocal (Menning et al, 2000), but the Langsettian is given as 319-318 Ma by Gradstein et al (2012, p. 605), rather older than the 314.5-313.4 Ma ± 1.1 Myr given in GTS2004 (Davydov et al, 2004).…”

Analysis of factors influencing the interpretation of a digitally examined fluvial meanderbelt system: Joggins Formation, Nova Scotia

“…The Cumberland and Mabou groups form a continuous and conformable 14.7 km long outcrop ( Fig. 5) along the coast of Chignecto Bay (Grey and Finkel 2011). Browne and Plint (1994) mention that the margins of the sub-basin include the North Fault to the south, the Caledonia-Dorchester fault system to the north, and the Harvey-Hopewell Fault to the west.…”

“…The sandbody is also a geobody, with the internal structures being the architectural elements (Choi et al 2011). The Joggins Formation coal beds have been the subject of studies pertaining to their deposition, composition, and hydrocarbon potential, with the findings summarized by Grey and Finkel (2011). Dawson (1854) estimated that the formation contained a mini-mum of 45 coal beds with varying thicknesses from less than a centimetre to metre scale.…”

The Pennsylvanian Springhill Mines Formation: sedimentological framework for a portion of the Joggins Fossil Cliffs UNESCO World Heritage Site

“…(Rygel and Shipley 2005). Although the coal-bearing strata of the underlying Joggins Formation was the subject of numerous studies in the following decades (Grey and Finkel 2011), the Springhill Mines Formation was largely ignored. Way (1968) studied a ~250 m interval (at 175-425 m in our section) and determined that the strata represent the channel, floodplain, levee, and backswamp deposits of a meandering fluvial system.…”

“…Aside from recent work on the underlying Little River and Joggins formations Davies et al 2005), much of the 4.5 km thickness of the Joggins section has not been described in detail since the pioneering work of William Logan (Rygel and Shipley, 2005). The lack of a basic sedimentological context for much of the section is a deficiency that prevents a fuller understanding of this iconic Pennsylvanian locality (Grey and Finkel 2011).…”