A Tale of Two Boulders


Fredonia Science Center
201 Houghton Hall
The State University of New York at Fredonia
Fredonia, NY 14063
Ph: 716-673-3285


Dr. Holly Lawson
Project Shepherd

Markus Kessler
Director of Facilities Planning

John Kijinski
Dean, College of Liberal Arts & Sciences

Betty Gossett
Associate Vice President for University Development

David Tiffany
Vice President for University Advancement & Executive Director of the Fredonia College Foundation

by Jack Berkley, Professor Emeritus
Department of Geosciences
SUNY Fredonia

Since 1985 an estimated 9-ton boulder has graced the front entrance to Houghton Hall. Discovered during routine pipe-line excavation activities by the Travid Development Corporation, the large rock was about to be hauled off to a local landfill when Dr. Walther M. Barnard, then Geology Dept. chairperson, asked that it be placed in its current position on the southwest corner of the building. Dr. Gordon Baird, department paleontologist and sedimentary rock expert, concluded that the boulder was derived from the Clarence member of the Onondaga Formation, an extensively exposed limestone unit easily traceable from the Buffalo area to well south down the Hudson valley. The boulder was likely plucked by a massive glacier from outcrops about forty miles north of Fredonia, then transported encased in ice to a site near here. It later calved off in an iceberg that floated in a forerunner of Lake Erie. At some point the iceberg melted sufficiently to allow the boulder to fall to the lake bottom where it was eventually completely buried by muddy lake sediments. “Ice rafted” rocks, like this boulder, of a variety of sizes, shapes, and compositions are commonly found in glacial lake sediments. Excavation in the Rugby field south of Houghton Hall finally revealed this rather large example of an ice-rafted boulder some ten thousand years after it traveled here, possibly from the Buffalo area or Southern Ontario. Evidence of its glacial origin includes parallel striations and surface smoothing typical of ice transported materials.

Houghton Boulder in 1985

 Houghton Limestone-Chert boulder in 1985 shortly after emplacement outside Houghton Hall entrance. Chairman Barnard stands in center flanked by Travid Development Corp. owners.

           Fossil in Houghton BoulderThe Houghton boulder is composed of gray, fine-grained limestone (mostly calcium carbonate), but with a very high content of gray chert nodules (silica, similar to “flint”). The Clarence member is characterized by its high chert content, but the Houghton boulder is unusual in that chert is volumetrically dominant over limestone. “Rugose” or solitary “horn coral” fossils are fairly common in the carbonate areas of the boulder, although most fossils are highly fractured and granulated suggesting a very high wave-energy marine (seawater) environment. The Onondaga Formation is Middle Devonian in age (around 380 million years ago) and was probably deposited on an off-shore continental shelf near the equator.

          Recently another large boulder was unearthed from proto-Lake Erie lake sediments during excavations of the sub-basement for the new STEM building. Like the Houghton boulder, it is also considered to be an ice-rafted glacial boulder. This new rock is a laminated carbonate unit (tan-brown, fine grained dolostone: calcium-magnesium carbonate) that is from a distinctly different rock deposition environment compared to the Houghton boulder. It appears to be quiet water lagoonal in origin with development of cyanobacterial stromatolites (fine-layered organic biofilms) on the sea bed. Cyanobacteria are one of the earliest oxygen-producing life forms on earth, and still exist today. Fish aquariums that are not well maintained commonly produce annoying mats of cyanobacteria (formerly called “blue-green algae”) on the glass walls. In nature, these formed in a very shallow, warm, restricted epicontinental seas (like the Black Sea or Hudson’s Bay) perhaps at 25-30 degrees south latitude. The source of the rock is most likely the Middle/Upper Silurian (about 425 million years ago) Guelph succession or the higher, Late Silurian (about 410 million years ago) Bertie Group interval on the Ontario peninsula.

close up of new boulder

          Like its Houghton Hall mate, this “new” boulder will eventually become part of the outdoor landscape design incorporated into the new STEM complex. Like the Houghton boulder, it will serve not only as an architectural enhancement, but as a teaching-learning attraction for SUNY Fredonia students and instructors.

 

THANKS to Gordon Baird for providing much information for this piece.

 


Page modified 7/15/14