GMS Field Trip April 2024

GMS Field Trip
Geodes, Marine Fossils, and Beekite in Kentucky
Saturday, April 6, 2024

We planned this trip so that attendees could be close to the path of totality of a solar eclipse that would occur only two days later. The chance to see a total eclipse was exciting, but members were also excited to collect geodes – some for the first time. But before we looked for geodes, we looked for trash. We always collect several large bags of trash from the area in exchange for access to the property. Despite their best efforts, members were only able to remove one large bag of trash because the water was a little too high to reach some of the worst spots.

After completing their civic duties, everyone was eager to find geodes! Daniel Miller was on hand with a geode cracker, and there were so many geodes that he really had to get cracking! Sometimes geodes at this location contain tiny, double-terminated quartz crystals that are loose inside the geode. Daniel always places a baggie around the geode, not only for safety to contain any pieces that might fly out, but also to capture any tiny crystals that might spill out. Although there were the occasional solid blobs, many of the geodes were lined with sparkling quartz crystals, mostly clear or milky, but some crystals had orange, red, and yellow hues too. Members also found beautiful geodes with smooth lumps of yellow, orange-red, or blue-gray chalcedony that is called “botryoidal” for its resemblance to clusters of grapes.

Paleontological finds for the day included horn corals, crinoid stems, brachiopods, and other marine fossils. The horn corals and crinoid stems found here often have very fine details preserved, e.g., ridges and joints between segments. This year I did not see any rugose colonial corals, but on prior trips, members have found specimens with good preservation of corallites. Some of the brachiopods and other marine fossils were casts of the shell rather than quartz or other mineral replacement of the shell; some were imprints or impressions of a shell; and some were embedded in rocks. No matter what they are or how they were formed, all of the fossils here are fun to find.

Beekite is usually associated with fossils and is my favorite thing to find at this location. It is an odd surface feature that occurs as concentric rings of chalcedony. Many of the rings are thin and somewhat wrinkly in appearance, but some are thick and smooth – more like tiny donuts. Geologists think that beekite forms when carbonate minerals are replaced by silica during the early stages of permineralization and the supply of silica cannot keep pace with the dissolution of the original material. Elsewhere, it forms during fossilization, so it is often seen on shells, corals, and other fossils; however, the samples we find here are either not fossils or cannot be identified as fossils.

After everyone collected as many geodes and fossils as they wanted, Charles, Daniel Miller, and I went to visit the property owner. Years ago, on another field trip to a stone processing plant, we were given a slab of rock cut into the shape of Kentucky. We presented the Kentucky slab to the property owner, who was excited to receive it and decided to have his family farm logo engraved into it!

It was a wonderful trip and an excellent way to start the eclipse weekend! It was just the beginning of a great adventure for Charles and me – and Gilligan, too! As was undoubtedly the case for the other people who attended the field trip, our travels continued into the path of totality. Many thanks to the property owner for inviting us to collect at such a special place. Thank you to the members who worked so hard to clean up the area, plus a special thank you to Daniel Miller, Patti Donehoo, and Michael Gropp, who were always on hand to provide assistance right when we needed it. And, as always, thank you to Charles Carter for arranging this trip!

Lori Carter on behalf of Charles Carter
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