Anyone who’s traveled I-55 toward St. Louis, say, an hour or so outside of Chicago, has likely spotted a number of large, anomalous, volcano-like piles spread out on private property along old Rt. 66. Almost without vegetation, they are other-worldly and towering above the grain fields around them. The “spoil heap” of Braceville, Illinois, is no exception; in fact, it may be the most distinctive and alluring of these remnants from the shaft mining days over a hundred years ago.
Braceville was a burgeoning coal mining settlement of the late 19th century, and once claimed 3,500 residents at its height in the 1870’s. High quality coal was discovered not far below the ground which supplied many localities in northeastern Illinois, including a rapidly growing (and energy needy) Chicago. Longwall mining systems employed in England were replicated in Will and Grundy counties, using an intricate lattice of wood-supported shafts, rail cars and mule teams to extract the coal. According to the records, the town sported six general merchandise stores, two banks, a hotel, two restaurants and 18 other retailers that thrived until the summer of 1910 when the miners of the Braceville Coal Company went on strike. Instead of negotiating with its employees, the ownership simply closed the operation and, within months, the town was all but abandoned, leaving behind an opera house, a large-frame school and many empty businesses.
A by-product of extracting anything from the earth is usually a disproportionate amount of waste material: usually stone, sometimes toxic. The undesirable rock – in this case, Francis Creek Shale – was conveyed into giant cone-shaped heaps and left to dissolve back to the earth. Aside from the unusual scale and placement of these “gob piles,” one would have little notion today that they were industrial at all, much less part of an important economic shift in the Midwest. Save for a few shards of wooden plank, rusted metal rings and spikes, and, of course, weathered-out chunks of coal, there is virtually no evidence of the great structures and process that transformed the region.
For all of the coal mining days past and beyond, it’s been known that concretions containing fossils were a residue of the operation. More often a hazard to the miners (indicating weaker shaft ceilings), they were once harvested for the iron they contained. Imagine railroad cars full of concretions heading for smelting in the blast furnaces of Indiana and Missouri...Today, we scour these heaps looking for nodules and the treasures they might contain. It’s not only an inversion of value, but a race against time; a hundred years or more of exposure to the elements grants access both to the collector and to the acids of rain and decaying sulfurous coal, even lightning, in this case. Red, ochre, and black seams in the eroded sides of the pile indicate the presence of nodules, but also of oxidation – the enemy to any fair fossil preservation. On the discovery side, it’s a matter of who will get to the center of a stone first: the eager collector – who will employ the patience-testing freeze/thaw technique, or render an expedient, if not more risky, hammer blow – or Nature herself, with winter and water reducing a once-hard concretion to silt and sand, thus erasing any evidence of prehistoric life.
A visit to the Braceville spoil pile last year through ESCONI granted me a couple of buckets full of rocks in various shapes and sizes. To be honest, I had no real idea of what I was looking for, save that a concretion, I knew, is harder than its surrounding matrix. Most were encrusted, and some even corrupted by oxidation all the way through. I heard that the more classically round or ovoid nodules typically contained jellies, and that very much proved to be the case. More spherical or flattened stones could yield other sorts of animals, or even a fern, but most of those were frustratingly blank and have been since relegated to the status of garden decoration.
It is fascinating to consider the intensity with which we fossil “hunters” search for these elusive concretions. Some of us come equipped with picks and shovels similar to the very tools used when the material was moved the first time. Boots and hammers allow us to scramble up the slippery gullies; bags and buckets harbor the coveted finds for later investigation. Though fossiling appears in so many ways to be a solitary activity – competitive, almost protective – I heard many whispers among the muddied visitors this year as to high-value insects being found at Braceville: last year, a Tully Monster. People showed off their prizes to one another, even raised unopened stones for the power they must have. I truly understand this latter impulse, for I have a few large and “perfect” unopened concretions that I’ve decided will remain this way. Knowing that we must practically destroy the stone to get inside it and, in all likelihood, it is blank or “only” a jelly, I have thought to stay in that zone of mystery in the process: the historic unearthing and casting as “waste,” the assault of the elements and reburial, the new value we place on the object, its discovery and removal. With all due respect to scholarship and the unrivaled specimens the concretions of Mazon Creek provide, the point of highest potential, intention, enigma and magic for me is the surviving concretion discovered, complete and in hand…300 million years in the waiting. Some will have to hold their secrets just a little longer.
Note: The Braceville spoil pile is on private property and the owners have been generous to grant us limited group access for fossil collecting. Please respect this privilege and stay tuned for future field trips organized by ESCONI posted on this website.
To see more pictures from the Braceville field trip, click on the Mazon Creek Collecting title in Photo Albums.
