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Eathie, on the stretch of coast between Rosemarkie and Cromarty on the Black Isle is noteworthy on two accounts. Historically, this stretch of coast lay on Hugh Miller’s home ground and it was one of the sites where he famously collected fossils in the 1800’s. Geologically, Eathie is one of the few onshore areas in Scotland where Jurassic rocks are exposed. More importantly, the fossils found in these rocks are excellently preserved. This has allowed for the study of animals, but more particularly plants, at the cellular level (through sectioning).
The rocks at Eathie formed during the Kimmeridgian period of the Late Jurassic (between 148 Ma and 142 Ma). They are generally sandstones and black shales with a few limestone beds. Syn-sedimentary sandstone intrusions cross-cut the black shales in places. These are the result of the liquefaction of sand by earthquakes, followed by their intrusion into local solidified sediments. It is most likely that the earthquakes resulted from movement along the Great Glen Fault which forms the sea cliff to the back of the shore at Eathie.
Although fossilised shellfish and ammonites are often found, it is the fossilised plants that give the site its importance. The fossils are permineralised, which has kept the organisms in an excellent state of preservation. Flower-like seed-heads found include Williamsonia scotia and conifer cones include Masculostrobus woodwardii and Conites juddii. Although these are marine-deposited rocks, the plants were land-dwellers, indicating that the area lay close to land (the plants would have been washed into the sea) at this time.