The Opinion of Calder:  

Although he may not agree with my conclusions, John Calder is (perhaps) better acquainted with the Joggins strata than anyone.  A few of his comments regarding this strata are cited below:

"Apart from the marine fauna of the Visean, virtually all other aquatic fauna of the Carboniferous in  Nova Scotia historically  have been described as nonmarine, which... is a too restrictive generalizationThe term 'nonmarine'  fails to describe the spectrum from  marine to  inland aquatic communities.  Aquatic invertebrate taxa  of equivocal affinity are found among  the agglutinated  foraminifera, spirorbids,  limulids, ostracods, eocarid  crustaceans and pelecypods. The crustacean fauna, including the eocarid Pseudotealliocaris- Anthracophausia and ostracod  Shemonaella- Beyrichiopsis communities  of the lower Mabou Group, belie the consistency of  'non-marine' conditions...1  Emphasis Added

"Similar comments  apply to the 'nonmarine'  bivalve taxa, wherein  an  ecological gradient from near marine to inland freshwater is likely.  Apart from Carbonicola of  the Windsor  and  Mabou Groups,  however, the taxa  found  in Nova Scotia historically have been designated respectively as  'nonmarine.'  The apparent contradiction that certain of these are associated with near-marine environments  in western Europe has been accommodated by invoking ecological  adaptation to the lower-salinity waters inferred  for Nova Scotia...  An exception is the study of  the Joggins section by Duff & Walton (1973), who concluded  that 'in the light of European studies curvirimula and Naiadites could suggest a salinity nearer the "marine" rather than  the "fresh" end of the spectrum."  1  Emphasis Added


"The section contains 49 recorded horizons containing  erect trees,...  and  new finds are constantly  being  made as  the cliffs recede and  the thin sediment cover  on the  wave-cut platform shifts.  The  most spectacular preserved trees  are up to 3 m tall and nearly 1 m in diameter near the base,  but many  are also visible truncated shortly above the base of the trunk. (Fallen logs up to  13 m long have been  found in  former  coal mines  in  the area). Virtually all lepidodendrid trees (lycopsids bearing the rootstock Stigmaria) are rooted  in coal beds, however  thin.  The trees are easily visible in the cliff faces, and  numerous occurrences with tens of trunks in a single layer can be examined in resistant  sandstone 'reefs'  that run  across  the  wave-cut platform."
2 Emphasis Added

"How the trees were entombed before they decayed  has always been a vexing question.  Our  sedimentological  studies show that the tallest  trees were entombed in 'bayfills' of shallow, standing-water bodies as a result of floods that  brought in large amounts of sand from adjacent distributary channels.  The  correlation of entombing  heterolithic sandstone beds with channel fills can be demonstrated by walking out the layers  across  the  wave-cut platform  at this locality.  The heterolithic sandstones that entombed  the Lepidodendrid forests  invariably  are characterized by the ubiquitous  presence of erect  calamites...  that  appear to have persisted by adventitious propagation.  The taphonomy of  the calamites and sedimentology  of the enclosing sediments indicate that  the heterolithic beds were  emplaced  at  intervals, presumably from successive, closely spaced flood events...  Most erect trees  are  sediment-filled, although a few are permineralized, including rare specimens of  possible medullosan (seed fern) affinity." 2  Emphasis Added

"As with all fossil  lepidodendrid  forests,  the  identification of  the trees even to the generic  level is a challenge due to their decortication..."  2


Additional Comments from the Nova Scotia Dept. of Natural Resources Web Site:

"In spite of its fame, advances in our understanding of the Joggins  section have been  painfully elusive..." 3

"The  classic Joggins  section lies within the Cumberland Basin...  It comprises the Joggins and Springhill Mines formations... of  the Cumberland Group (Ryan  et al.,  1992), exposed between Lower Cove and McCarron's  Creek in a near-continuous section nearly 2 km  thick." 3   Emphasis Added

"Shallow nearshore facies... are largely wave-dominated shales and  sandstones, with hummocky  cross-stratification  (HCS) and  wave ripples.  Large-scale  (50-100 m across) domal forms can  be observed in the cliff  and wave-cut  platform exposures.  They include stacked HCS  units and delicate  exposure features  (planed - off ripples, back-wash drainage structures),  and are interpreted as the  deposits  of nearshore bars.  Dark,  organic-rich  limestones up to 1 m thick  contain an abundant  shelled fauna.  Brackish marine (?estuarine) conditions are  indicated by  the  trace  fossil suite, foraminifera, and recent Sr  isotope data on  fish fragments (see Calder, 1998)." 3 Emphasis Added

"The coal beds of  this  famous section have received  surprisingly  little study, and the  bulk of what has been done is  largely  unpublished  as  yet.  Coal beds of the  Joggins  Formation  typically are  thin... Typically the coals  are  bright, clarain-rich  and pyritic ..." 3  Emphasis Added

"Analysis of  the hydrocarbon - generating  potential of  basin wide organic-rich limestones and  'clam coal' beds from the Joggins section reveals that they contain 1.41  to 13.10% TOC...Hydrogen indices in the range of 316-978 suggest derivation from algal and vascular plant sources, with kerogen types 1, 2  and 2 to 3 represented. These data are consistent with widespread flooding  events, possibly from a marine source, of lowland plant communities." 3 Emphasis Added

"The Joggins section is a coastal to alluvial succession, and should be a good candidate for recognition of high-resolution Exxon sequences,  sequence boundaries and  systems tracts. However, our detailed analysis has failed to identify sequence boundaries in the section,  despite the very complete exposure. Paleosols are apparently immature throughout, and channel bodies are meandering or anastomosing in  style, in  accord with the associated floodplain facies. There are no indications of major basinward shifts of facies... Instead, the section is dominated by a hierarchy of  flooding  surfaces, and these  define parasequences  that  are stacked  in  progradational and  retrogradational sets.  The flooding surfaces are marked by bivalve-ostracod limestones, coals and carbonaceous shales, grey mudstones in predominantly red successions,  and ostracod (freshwater) limestones in some redbeds.  The parasequence sets  form  large-scale cycles (50-200 m thick) that... vary from near-symmetric to  strongly asymmetric in  their  facies organization.  The  sharp-based nature of most subtidal sandstone sheets suggests that many progradational  events were associated with  base-level fall... although the falling levels were apparently insufficient to cause incision and valley formation at this locality."  3 Emphasis Added


"It is  probable that rapid subsidence in the Cumberland  Basin, with  an abundant sediment supply, allowed sedimentation to be virtually continuous. Under these conditions, major hiatuses that would be  represented by  valley fills  or mature paleosols would  not be generated.  Such a style of basinal filling through a thick succession is unusual, and forms an  interesting  contrast to the better known Exxon model." 3   Emphasis Added

  1. Calder, John H., 1998, "The Carboniferous evolution of Nova Scotia," in Lyell:   The Past is  the Key to the  Present, Blundell, D. J., & Scott, A. C., editors, Geol. Soc, Lon. Special Pub.  143, pp.261-302. 

  2.   Calder, John H.,  http://www.gov.ns.ca/natr/meb/98ofr5.htm#stop5.2 
  3. http://www.gov.ns.ca/natr/meb/98ofr5.htm#stop5