Many of the posts on this blog discuss the wide variety of life you can find in urban environments. But have you ever considered the diversity you can find in the very stones of the buildings we live in? Depending on where these stones were mined, you might be able to find some neat fossils.
Of particular interest is limestone, a material used in cement and the paving of roads and sidewalks. It is one of the most common types of sedimentary rock, and, depending on the locality from which it originates, it could be very likely to include fossils. Limestone is primarily formed in shallow seas from the remains of calcareous micro-organisms that live there. These shallow seas were much more prevalent during periods like the Jurassic and Cretaceous, as the Global Sea Level was higher and shallow bodies of water covered part of the continental plates. Therefore, many of the fossils found in limestones originate from either the Jurassic or Cretaceous Period.
For those curious for examples, consider the buildings in Maastricht, The Netherlands. The area around Maastricht contains many quarries that expose Late Cretaceous strata. These sediments are often grainy but are used in cement and blocks of them may be used in walls, especially in old times. If one looks at the walls in Maastricht, do not be surprised to spot the occasional bivalve or sea urchin.
Another example includes the area around Solnhofen, Germany, from which tough, plate-like tiles have been mined for centuries. Looking around at the floor and pavements, might reveal a curious ammonite, which can even be neatly split apart, if you’re lucky. Finally, in Lisbon, Portugal, the local Department of Geology have even begun to engage citizens and tourists, placing QR codes near the various fossils of gastropods, bivalves, crinoids, etc. that you can find in the pavement, with a link to more information on them.
These are just some simple highlights of limestone finds from the Cretaceous Period. However, every type of building material has a different history and thus a chance at finding different fossils. If you look closely, color of the stone in buildings, and the fossils you can find within, might even tell you a story of where the materials of a specific building came from. Overall, this piece is a request for lovers of fossil to pay greater attention to the world around you. You’d be surprised at the diversity you can find, if you look past your average pigeon and their occasional droppings.
References
da Silva, C. M. (2016). Fossils, Smartphones, Geodiversity, Internet, and Outdoor Activities: A Technological Geoeducational Bundle. Geoscience Education: Indoor and Outdoor, 133-157.
Francischini, H., Fernandes, M. A., Kunzler, J., Rodrigues, R., Leonardi, G., & de Souza Carvalho, I. (2020). The Ichnological record of Araraquara sidewalks: history, conservation, and perspectives from this urban paleontological heritage of southeastern Brazil. Geoheritage, 12(3), 50.
Reumer, J. (2020). Stadspaleontologie. Historische Uitgeverij (Groningen), 160pp.
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