December 16, 2000 - Pennsylvanian Fossils, Walker Co, AL

by Ron Buta, Department of Physics and Astronomy

    University of Alabama
    Tuscaloosa, Alabama

    The Union Chapel Mine is now known to be one of the best Lower Pennsylvanian track sites in North America. During December, the mine was in the process of reclamation, and the BPS returned one more time as a group to search for trackways among turned-over spoil piles in one of the most productive areas of the site. About 15 BPS members and several newcomers attended the field trip on a pleasant mid-December day.

    Figure 1: Trackway of a likely arthropod. Each print is a small spot.
    When we arrived at the site, only one small area was not reclaimed. This particular area was one which had yielded many good tracks in the past and so we were all delighted to see that the mine workers had moved some of the old rock piles around, allowing us to see if any new material had been exposed. In spite of this, we all had difficulty finding any new high quality tracks. Nevertheless, there were still tracks to be found. I found the interesting specimen shown in Figure 1. It appears to be the trackway of an arthropod, where each track is a small roundish spot. In the significant collection of track photos which the BPS "track meets" have provided, I had not seen another set like this one. I also found the tracks shown in Figures 2 and 3.
    Figure 2: Trackway of another likely arthropod, notable for its asymmetry and strong trail-dragging mark
    Figure 3: Two tracks of an Attenosaurus subulensis, a common alligator-like amphibian from the Union Chapel site.
    On the reclaimed areas and in the overturned area, one can still find nice plant fossils at this site. Figure 4 shows an especially nice set of ferns from a split rock. Most interesting is how strong the stem of these ferns is.


    fernFigure 4: Strong fern impressions from a split rock.
    Figure 5 shows brown ferns of the genus Neuropteris, which was common at this mine.
    fernsFigure 5: Beautiful Neuropteris ferns defined by iron compound deposits.

    Figure 6 shows a single large seed impression of a seed fern. This is how such seeds are often found.
    seedFigure 6: A seed impression, Trigonocarpus.


    However, I found another rock in the overturned area having more than a dozen seed impressions. Several of these are shown in Figure 7.

    seed impressionsFigure 7: Part of a slab showing numerous seed impressions

    The ferns they are associated with are shown in Figure 8. Jim Lacefield discusses the seeds of seed ferns on page 66 of his new book, "Lost Worlds in Alabama Rocks", and gives a wonderful general discussion of the Coal Age in Alabama and what happened to the seed ferns.

    ferns and seed impressionsFigure 8: Part of the same slab showing another seed impression among the ferns likely associated with the seeds

    The reclamation of the Union Chapel Mine caps off a spectacular year of discovery for the BPS, and the Union Chapel experience marks the beginning of a remarkable cooperation between BPS amateur rock collectors and two professional organizations, the Geological Survey of Alabama and the Alabama Museum of Natural History on this new project. The more than 500 track specimens salvaged by BPS members and guests since January 23, 2000 are currently being researched by professional paleontologists. Hundreds of high quality plant fossils were also salvaged and will eventually be studied. We will no doubt be talking about the experience for years to come.