|In Washington Township, situated
in the southwestern part of Will County, Illinois, coal mining has in
recent years been practiced by stripping all of the sand and clay
overburden down to the coal seams and then removing the coal from the
excavation. The sand and clay stripped off is thrown aside in
irregular piles over one hundred feet high in some places. In the
not far above the coal are many pebble like concretions or nodules,
large and small, heavily impregnated with iron. Many of the
nodules, when split open, yield fossil plant impressions, also
occasional specimens of animal life, such as fishes, insects and others
like centipedes, horeshoe crabs, etc.
Geologically, the deposit is the Paleozoic Coal Measures designated as Pennsylvanian. It is clearly related to the not far distant Mazon Creek site in Grundy County, Illinois, where plant impressions have long been found sealed in nodules or stone packages so finely preserved that the finest leaf-veining is discernible as if it was in life. Mazon Creek fossil plants have been collected for over 75 years or more and are known to paleobotanists all over the world.
About 25 years ago I did considerable collecting at Mazon Creek but did not continue very long, for several reasons. Securing prolific nodules was slow and laborious work; the stone was rather soft, and the plant impressions easily marred; and although there were many species, they had a drab sameness in appearance that soon became wearisome. So much collecting had been done there that the chances were small for finding new species. Gradually I lost interest, and my visits to Mazon Creek terminated in 1915.
Strip coal mining has been going on in the Wilmington district for a considerable time. I heard of plant-bearing nodules found there, but for some years felt no great interest. However, in October 1937, my son George, Jr. and I drove down to the coal fields 23 miles from Joliet to have a look. We roamed over the clay heaps splitting nodules and repeated this performance a week later. We continued this once or twice each week whenever favorable weather permitted.
Driving down to the clay heaps from Joliet was simplified by the fine new concrete highway No. 59. We would get the car close to the clay heaps and bring the nodules to it in five gallon pails. About 12 pails would make a good load. We did not split the nodules open in the field, for it was Winter and the weather was too cold for that.
Half a dozen visits to the clay heaps impressed me with the belief that I was at the beginning of an adventure which promised more than my former collecting experiences at Mazon Creek. The species of plants found in the new site were very similar to those found at Mazon Creek, and yet although the latter site had failed to sustain my interest, work in the clay heaps impressed me very differently. In the first place, the clay-heap nodules were much easier to get by ten to one. At Mazon, the nodules are generally composed of flat laminations decreasing in area outwardly, being stratified like the clay shale in which they lay embedded. The nodules of the clay heaps were most of them smooth like pebbles and seemed to have been formed around a central nucleus instead of above and below it. Much of the stone was very hard and compact, although in some places it was relatively soft and of a light brownish color as at Mazon. And yet I found great variation in the stone composition. Much of it was hard and almost flint-like. These was also a great range of stone color. This latter feature alone inspired me to keep clambering over the clay heaps in the cold and wet, filling pails with nodules and lugging them to my car. I was like a child playing with colored toys. We found many good specimens, but what interested me most was their variations of color.
Some observers would say that the variations of color were largely imaginary. When split open, the nodules looked like freshly broken rock, and the plant-like impressions were usually defaced by blotches of extremely tenacious white calcareous and sometime silicious mineral substance which was very difficult to remove. As our collection of specimens grew, it did not impress me as it should have done. We were finding good specimens of many species, some of them new to me, but their drabness and sameness of appearance impressed me as the Mazon Creek fossils had done. The only virtue I could see in them, was color.
In truth, the element of color was [indeed] largely imaginary. Unlike other forms of fossils, the plant impressions are beautifully preserved and life-like in the retention of form and of the tiny veins. As far as color, some are blotched with white, and others are not readily distinguished from the stone around them. The absence of sharply contrasting color in these fossils is not suggestive of life, but the variations of stone color presented an opportunity for making contrasts by subduing the surrounding stone color and accentuating the plant color. This may be termed, "developing."
The plant-bearing nodules may be considered as photographic plates exposed 250 million years ago. We split the stone, and the exposed plate is developed. The plant picture is relatively obscure at first but gradually the surrounding field clears away and the plant picture comes forth sharply distinguished. And the plant pictures have contrasting colors, these colors being derived from the differences in stone color in the various specimens. They are not the original plant colors, but they are colors: brown in one specimen, blue in another or black or violet or carmen. In a series of specimens, these various colors suggest life. The plant impressions stand out so sharply from the background, that they seem to be painted on the stone. But no paint is needed. The color is really there although obscure, and it is simply a case of making that color stand forth. Like many other things, these fossil plants have charms hidden away which may be appreciated if they are accentuated, but unlike other fossils, the accentuation of their charms give in them the suggestion of life. Furthermore, they are more distinguishable and more interesting to the layman than when left in their drab and relatively obscure, original condition. Nothing ficticious is added. Developing the fossil pictures merely accentuates what was already there.
Certain women became interested in these developed plant pictures, and this led to a talk about them by my wife [Sydne Holmes Langford - GL,III] to the Joliet Women Gardener's Club in February 1938. It was an excellent talk, entertaining as the audience expected, and also full of science which was rather unexpected, seeing that Mrs. Langford spoke extemporaneously on her subject of a Will County garden of 250 million years ago. A display of the developed plant fossil plants was there to accompany the lecture. It was quite apparent that the affair was a complete success. First, these women were interested, then vastly entertained, and finally enlightened scientifically on the fossil plant life of Will County, Illinois. They had really been subjected to a scientific lecture on a subject, which as laymen they knew little about and which ordinarily they would have cared even less about. And yet they were the ones who engineered the whole affair. A collection of ordinary fossil plants would not have inspired their interest, but a display of developed and revived fossil plants was an entirely different matter. These women were interested in them and then took to the subject as a whole like ducks to water. They appreciated not merely the entertainment feature but also the scientific side of the fossil plants. It was an interesting experiment.
[all in his own handwriting and initialed] GL,Sr., March 1, 1938