EGU Blogs

Geology Photo of the Week #25

The photo for this week is something a bit different. It is a piece from my personal collection that was self collected. Ok, full disclosure, my dad actually found it, but I was over on another rock pile in the quarry and finding jack at the time…so it is self collected….I did help extract it after he found it. I should also mention that they were repaired and enhanced by a professional to make them really “pop” out of the rock. However, no parts were added. They were found as complete specimens.

I don’t want to steal any paleontological thunder from Jon, but I have a fair amount of experience in paleo, particularly invertebrate paleo. In fact, the part of southern Ontario that I grew up in is stuffed with Ordovician fossils such as the trilobites pictured below. These particular trilobites, known to my family and others as “Bert and Ernie”, can be classified as Isotelus gigas, which is a common species in the region. However, complete trilobites of this size are exceptionally rare and to find them as a pair is simply ridiculous. Bert and Ernie were found in Colborne Quarry, a limestone aggregate quarry, famed among local collectors for its fantastic fossils. I used to go  to the quarry on a regular basis and found all sorts of great stuff over the years from complete crinoids to 1.5m cephalopods. Unfortunately  the company that owns the quarry has closed it to collecting and access is no longer possible. However, there are still lots of other places in the area where it is possible to collect in the same rocks. Stay-tuned for more personal collection highlights in the future. I have nice cephalopod that is hiding an unusual secret…



Matt Herod is a Ph.D Candidate in the Department of Earth Sciences at the University of Ottawa in Ontario, Canada. His research focuses on the geochemistry of iodine and the radioactive isotope iodine-129. His work involves characterizing the cycle and sources of 129I in the Canadian Arctic and applying this to long term radioactive waste disposal and the effect of Fukushima fallout. His project includes field work and lab work at the André E. Lalonde 3MV AMS Laboratory. Matt blogs about any topic in geology that interests him, and attempts to make these topics understandable to everyone. Tweets as @GeoHerod.


  1. Note to self – add “Ontario” to list of places to go in 2015. Be prepared for mucking great heavy bags on way back.

    • For sure! There are still lots of other quarries that are still open and contain the same formation. In this case I am pretty sure it was the Bobcaygeon, although it is hard to be certain since they were found in a pile as opposed to the quarry wall.

  2. There’s a free cross stitch trilobite pattern here for the nerdy stitching geologists:

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