Calamites

July 24, 1999 - Pennsylvanian Fossils - Walker Co, AL

Department of Physics and Astronomy
University of Alabama
Tuscaloosa, Alabama

This field trip was a very special one for the BPS. We visited a surface coal mine in Walker County. About 20 BPS members and guests attended the trip, which occurred on one of the hottest and most humid days of the year thus far.

This is one of the largest surface coal mining operations in the state. The area is part of the major Pottsville Formation, and is also known as the Warrior Basin. The BPS was hosted by Mr. Hendon, a mine engineer, who also brought his son along. Mr. Hendon first gave us a basic description of the mine, its history, its extent, and the geology of the area. He then took us on a tour of the mine, allowing us to park near a monster machine known as a "dragline". To access the coal seams, overlying soil and hard rock has to be removed, which is the principal task of the dragline. Usually there are 100-200 feet of solid rock to be removed, but on Saturday the dragline was mostly removing topsoil.


--Edited by Vicki Lais

dragline
The dragline. The 180 ton
bucket is hanging in the middle
of the photo.
climbing into the dragline
Climbing into the dragline.

lot of people in the bucketThe machine uses a 180 ton metal bucket to drag soil and rock forward
for lifting, and then rotates to dump the material on an area that has
already been mined. The machine is so large and so specialized that,
according to Mr. Hendon, it cost $36 million when it was brand new. Not
only were we allowed to view the dragline from close up, but we were
also able to go inside and see how it works. The movements of the
bucket can be efficiently operated by one person, but three other
workers are usually present to keep the machinery functioning and
oiled. The complex manipulations of the dragline depend on 16 giant
motors of over 100 horsepower each, one of which we saw winding and
unwinding the huge cables connected to the bucket. Other motors rotate
the whole assembly and move it. We all visited the operator control
room, as well as a second empty control room. Inside the machine, the
noise was loud enough to necessitate the use of earplugs. After
visiting the dragline, Mr. Hendon took us all to a second bucket no
longer in use, where I took the group photograph shown here.

 

After this part of the tour, Mr. Hendon
then led us all to an area
where we could search for plant fossils. Like many other sites in
Walker and Jefferson Counties, plant fossils from the Carboniferous
period are present in abundance at Cedrum. Mr. Hendon first pointed
out to us a couple of fossil stumps of arborescent lycopods, one of
which was partly removed by BPS members James Lowery and Danny Brooks.
The piece Danny Brooks showed me weighed about 100 lbs and showed
characteristic
scars of a likely Lepidodendron. Interestingly, the cross section of
the
stump showed scars as well, but I am not sure exactly what these
represent.
Danny has very graciously donated the specimen to the Southern
Environmental
Center, who plan a special display.
 
Other items found at the site included numerous
medullary casts of the
familiar Calamites, a member of the horsetail phylum. The largest piece
shown to me was about 8 inches long and about 4 inches in diameter.
All of the pieces I saw, including a small one I found myself, showed
well-defined linear furrows and ridges aligned parallel to the
direction
of the stem. The raised furrows represent vascular bundles of the
plant, and
are basically inverse impressions of the life features. The narrower
ridges,
also inverse, are known as medullary rays. The casts represent the
inner
pith cavities of the plant, which were either hollow or had only soft
tissue that quickly decayed. When these cavities filled with mud, the
mud solidified and preserved an impression of the
stump in rock wall

inside of the plant.
Some specimens looked broken at a node, a place where leaves and
branches could emanate from the plant. The node is a horizontal ridge,
and the small specimen I show here has two nodes. Sometimes a node may
be preserved
in cross-section. On splitting one rock, I found a large node
impression
with thin radiating structures, probably leaves. However, none of the
inner structure of the node was preserved in this piece.

 

 

LepidophloiosOne of the most interesting fossils I noticed at this site was a
modest-sized bark impression of Lepidophloios, a subgenus of the
Lepidodendra. The leaf scars of Lepidophloios are very much like those
of a normal Lepidodendron stem, only the scars are elongated
horizontally, rather than vertically. Although I have read that fossils
of Lepidophloios are the most commonly found plant fossil in Alabama,
it was the first time I had seen a definitive example. It was easily
distinguished from the better known Lepidodendron.

Also found at
the site were various seed fern impressions, the most familiar ones I
noticed being Alethopteris and Neuropteris. The latter were often found
as disconnected and relatively large pinnules. One BPS attendee showed
me a nice slab of intact Alethopteris ferns. He was so happy to have
the slab, and it was so fragile, that he said he was going to carry it
home on his lap! Related to these ferns, I believe I found what appear
to be two branches of a likely tree-sized seed fern plant. The branches
have a brownish color with some carbonized plant material remaining,
and bear no resemblance to the branches of Calamites or the arborescent
lycopods. No fern impressions are attached to these branches, but I
have seen other similar specimens having attached ferns.

 

 

lycopod stump
Easily the most spectacular find of this trip was a 300-400 pound
arborescent lycopod stump found by James Foshee. The specimen is about
1 foot thick and tapers from a diameter of about 2 feet to 3 feet from
top to bottom. All around the rim, the stump is covered with beautiful,
well-defined leaf scars, the appearance of which suggests to me that
the specimen is of the genus Lepidodendron. From its curved shape, it
looks like a part of the lower base of a much larger trunk. The
preservation is as good as any I have seen of these trunks in museums.
A happy day for James!

In summary, this was a really great field
trip for the BPS. If it had not
been so hot, it might have been even better!

 


 

 

May 29, 1999 - Carboniferous Fossils - Jefferson Co, AL

Department of Physics and Astronomy
University of Alabama
Tuscaloosa, Alabama

The field trip on May 29, 1999, was to an abandoned strip mine in Kimberly that is now being re-excavated by the owner of the Warrior site which was described in the report of the March 27, 1999, BPS field trip. This is a new site for the BPS and we were most likely the first people to seriously look for fossils in the area, at least since the mine was active.

Although the postcard for the trip stated that we would be visiting the same Warrior site as on March 27, it was understood at the last BPS meeting that we would visit the new site and check it out. We decided to visit the new site first and left it as an option for attendees to visit the site on their own, since that site is much easier to find. About 15 people, including BPS members and guests, attended today's field trip.

--Edited by Vicki Lais

hillsideThe site turned out to be a particularly good one for finding a variety of Carboniferous period plant fossils. The area was so vast that even with 15 people we really did not explore it all. Many rock piles surround an open area where we could park our vehicles. Fossils of Calamites, including 3D stem casts, stem impressions, foliage, and cones were abundant in some areas.

Ferns seemed less abundant, but good specimens were found nonetheless. Finely detailed fossils of the top foliage of arborescent lycopods were found in abundance. Bark impressions of Lepidodendron and Sigillaria were also found.

The main difference between this site and the Warrior site is that the fossils at the latter site are concentrated in a small area that is easy to explore.

At the Kimberly site, the fossils were spread out over a much larger area and finding them required a great deal of tenacious searching. Also, since you could not necessarily drive your vehicle up any of the steep hills, carrying a large fossil to your car was challenging to say the least.

ChristinaThere were numerous highlights of this trip. One attendee showed me a rare (so far as I know) cast fossil of a small part of a stem of Cordaites, a gymnospermous tree with no modern relatives. The stem of this tree consists of a series of horizontal ridges and is easily distinguished from Calamites, but I had never seen one this nice before. Some very nice pieces of Calamites itself were found. The inimitable Ken Hoyle showed several of us two spectacular Calamites casts he found, each about 6 inches long and 4-5 inches in diameter. The two pieces were obviously part of the same plant, but he could not find any of the missing parts.

 
Steve, Dena, and Molly Hand were also very successful in finding good 3D casts of Calamites, as well as a nice piece of Asterophyllites equisetiformis, the characteristic foilage of the branches of Calamites. Ken Wills, who previously spoke to the BPS last year, found a nice piece with many Calamostachys impressions, representing the cones of Calamites. Christina and Larry Hensley found a big rock with a stunning impression of the bark of a Lepidendron arborescent lycopod. It was beautiful but too big for anyone to carry. 3D casts of the rhizophore of Stigmaria ficoides, the root system of arborescent lycopods, were also found by several attendees, including myself. The largest, 15 inches long, was found by Bruce Relihan.
lycopod This small piece shows impressions of the upper branches of an arborescent lycopod.

 

Sigillaria Partial cast fossil stump of Sigillaria, an arborescent lycopod. The dark scars are the usual parichnos scars associated with this genus. The stump is about 1 foot in diameter

Particularly interesting were the stump fossils found at this site. On the top of a hill, I found three fossil stumps of Sigillaria. All three pieces showed the characteristic parallel bands of parichnos scars. The two largest pieces are about a foot in diameter and 3 to 6 inches thick. A smaller piece showed the strongest bands. I managed to get these to my car with difficulty, and needed help with one piece. Gerry Badger had a tougher time, however. He found a much bigger stump of Lepidodendron and practically had to roll it down to his car from some distant point. The stump looked to be 70-80 lbs in weight and showed weak scars. A very much larger stump was found by several others near the base of a hill. I heard it was maybe 30 inches in diameter. But by the time I heard about it, I had no energy to go and see it! Ken Wills and Bruce Relihan also found partial stump casts.

In summary, this was quite an interesting field trip. When I first "scouted" out this site in April, I was not sure we would find much since casual searching during a period of one hour did not reveal many fossils. The intensive searching by attendees on this trip was much more revealing about the site, and showed it to really be nearly as good as the Warrior site. It will be worthy of a second visit in the future.

 


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