COMMENT: NO MAJOR STRATIGRAPHIC GAP EXISTS NEAR THE MIDDLE-UPPER PENNSYLVANIAN (DESMOINESIAN-MISSOURIAN) BOUNDARY IN NORTH AMERICA: PALAIOS, v. 26, no. 3, p. 125-139, 2011

Abstract

Here I provide critical notes on a multiauthored paper purported to show the absence of a major gap in the Upper Pennsylvanian stratigraphic succession in North America (and, by inference, in northern Western Europe). It is observed that intellectually satisfying explanations for the discontinuities in the North American successions, having recourse to climate-driven alterations, do not take into account that the more continuous succession in northwestern Spain only shows gradual changes in floral composition. Inaccuracies in the use of scientific literature are pointed out. Perhaps, there are few experiences so satisfying as to see complacency disturbed, and to bring a large continental area, like North America, in contact with a wider world. The closing of the ranks, as exemplified by Falcon-Lang et al. (2011), is a very human response to new information from outside brought to bear on a large continental area where the general assumption has been that size guaranteed completeness of record. Of course, not everyone subscribed to this notion. David White’s papers on the Carboniferous of eastern North America show an awareness of certain comparisons with North and Central European successions that imply changes in stratigraphic development attributed to climatic changes, the suddenness of which inspire doubts about the continuity of the stratigraphic record. Darrah (1969, p. 26) mentioned ‘‘a marked floral break’’ in mid-Conemaugh of the Appalachian succession, and Kosanke and Cecil (1996) also observed a floral break. It may be helpful from a historical perspective that the present writer, after a couple of decades involvement with the International Union of Geological Sciences (IUGS) Subcommission on Carboniferous Stratigraphy (as Secretary and Chairman) was engaged for a report (unpublished) analyzing the Carboniferous (Pennsylvanian) stratigraphy of the British, northern French, Belgian, Dutch and West German areas surrounding the southern North Sea. This involved a revision of borehole material in the Netherlands and the examination of borehole samples in West Germany, in close cooperation with H.W.J. van Amerom. A major conclusion was the recognition of a sizeable lowangle unconformity, with physical evidence including secondary reddening, between lower Rotliegend and various different levels of upper Westphalian strata. The size of the unconformity could only be grasped by the recognition that most of Stephanian time was missing. The date of the unpublished report was 1985. This knowledge was available (privately) when P.C. Lyons (U.S. Geological Survey, Reston) organized a joint fieldtrip in the Appalachians in 1995, primarily with the aim to establish the level at which the Westphalian-Stephanian boundary could be recognized in the Appalachian succession. This had been assumed to lie close to the Middle