Stephen K Donovan (The Netherlands)
Much of the secondary railway route in Derbyshire, from Buxton south to Ashbourne, was closed in the 1950s and 1960s. Today, only the northern section is still in use as a railway, providing a route for major limestone quarry traffic (Roberts and Emerson, 2018). But the remainder of the line, from about 2.25km north of the closed Hurdlow station (Rimmer, 1998, p. 102), all the way to Ashbourne – a distance of about 27.5km – is now open as a cycle path called the Tissington Trail. This is part of the High Peak Trail north of High Peak Junction, which is south of Parsley Hay, and provides excellent access. For a map, see http://www.peakdistrict.gov.uk/__data/assets/pdf_file/0009/90486/hptisstrails.pdf.
The interest of this route for the geologist is that most of it is through the Carboniferous limestones (Mississippian) of the Derbyshire plateau. The beauty of the scenery combines with the accessibility of exposures in railway cuttings to provide much of interest to the geologist on foot or bicycle. The northern part of the route, from south of the site of Hurdlow station, through Parsley Hay (with cycle hire and a cafe) to Hartington, is described in a brief field guide by Simpson (1982, pp. 102-107).
My interest in these limestones is for their fossil crinoids. These are commonly difficult to see in the massive beds of limestone, which, over many years, have developed a surface patina that conceals internal features such as fossils. As this is a national park, there is no recourse to hammering, but there are other ways to prospect for fossils. For example, I have been exploring for rare, thin mudstone horizons with included ossicles (Donovan, 2018) (ossicles are the small calcareous elements embedded in the dermis of the body wall of echinoderms, including crinoids, forming the endoskeleton.) and loose cobbles that have been etched on the surface by many years of weakly acidic rain (Donovan and De Winter, in press). The latter are analogous to some building stones in cities where limestones in facing stones and bollards have been etched (Donovan, in press, figs 1b, 2a, 3b, h, 5b, 6a, c).
For the avid palaeontologist armed with a camera, there are other, perhaps less expected sources of data that can be found it you are alert. Consider, for example, the site of the closed station at Hartington. Much of the lineside space formerly filled by wooden platforms and buildings, and sidings (Sprenger, 2013) is now filled by trees, but one structure, the signal box (Fig. 1A), has been preserved. On summer weekends and holidays, the brick base is open as a cafe, serving drinks, snacks and ice creams, which can be enjoyed at one of the several picnic tables. There is ample space for parking cars and, in consequence, it is a popular starting point for cyclists. The facilities are completed by a relatively new toilet block (Fig. 1B). It is the external walls of this latter building that fascinated me.
The sandstone blocks at the corners (Fig. 2A) have been decorated and are certainly attractive. Unfortunately for the geologist, this has destroyed the surface manifestations of any internal sedimentary structures, such as bedding. That is, their effect is entirely decorative.