![]() ![]() It is a mixture of clays and creamy limestones. The Junction Bed is an example of a condensed sequence and was deposited in fairly deep water. In more recent times work on the A303 created new exposures of the junction bed in 1987. The most famous of these was Strawberry Bank, renowned for the vertebrate fossils and insects it produced. The beds around Ilminster were formerly exposed in small quarries which produced stone for building. Many broken coil sections of larger specimens can be found. This is especially the case with larger ammonite species such as Harpoceras. Modern powerful ploughs break through them. The old ploughs were more likely to push the ammonites to one side. Sadly, modern ploughing with tractors damages the ammonites more than the horse drawn ploughs of the past. It is also at these times that fossils are most easily found. This is most likely to be obtained when the fields have just been ploughed and contain no crops. Inland exposures are only accessible with the permission of the landowner. The coastal sections of the Junction Bed can be easily explored on the beach between Seatown and Eype, with the usual warnings about tides and cliffs. Many farmers charge per day of fossil hunting. ![]() Please seek the landowners permission before raiding their fields - or you could be done for trespassing and theft. The Beacon Limestone Formation, found at Ilminster, Moolham, Herne Hill, and Hurcott, is where Junction Bed ammonites or ‘Ilminsters’ can be found. Geological Map of Ilminster and the surrounding area, provided by the British Geological Survey. Despite these changes most fossil collectors still know the rocks around Ilminster as the Junction Bed. The Barrington Member together with the Marlstone Rock Member make up the Beacon Limestone Formation. This is to commemorate the exposures which used to exist around the village of Barrington, near Ilminster in Somerset. Around Ilminster the Toarcian rocks are now properly called the Barrington Member. Howarth has now demonstrated that the top of the marlstone is in fact Toarcian in age, containing the ammonite Dactylioceras tenuicostatum. It was originally applied to the Toarcian limestones and clays we think of as the Junction Bed today, and also the underlying Marlstone, which was considered upper Pliensbachian in age. The name Junction Bed has a long history. Fossils of the same age can also be found on the Yorkshire coast at places like Whitby, Port Mulgrave and Sandsend. The ammonites from these beds are common and relatively inexpensive fossils in many fossil shops. This partly reflects the nature of the exposure but is also a genuine difference in the beds. Despite the closeness of these two sites the collecting is different at each of them. Fossils from the Marlstone rock and Junction bed (now known as the Beacon Limestone Formation) can be found on the Dorset coast between Seatown and Eype and also in the Fields on the higher ridges around Ilminster.
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