ISSN 1750-855X (Print) ISSN 1750-8568 (Online) An introduction to 700 million years of earth history in Shropshire and Herefordshire 1 Peter Toghill TOGHILL, P. (2008). An introduction to 700 million years of earth history in Shropshire and Herefordshire. Proceedings of the Shropshire Geological Society, 13, 8–24. The beautiful landscape of the Welsh Marches is underlain by a rock sequence representing 10 of the 12 recognised periods of geological time. This remarkable variety, covering 700 million years of Earth history, has resulted from the interplay of three main factors: (1) erosion and faulting which have produced a very complex outcrop pattern; (2) southern Britain's position near to plate boundaries through most of late Precambrian and Phanerozoic time; and, most importantly, (3) the incredible 12,000 km, 500 million year, journey of southern Britain across the Earth's surface from the southern hemisphere to the northern, caused by plate tectonic processes. 1Church Stretton, Shropshire, UK. E-mail:
[email protected] BACKGROUND This paper set the geological scene for the one-day symposium at Ludlow forming the centrepiece of the 2007 Marches Festival of Geology. However, this is not the place to provide a detailed description of the geology of Shropshire per se, for which the reader is referred to Peter Toghill’s Geology of Shropshire (2006), thereby to benefit from the author’s detailed knowledge of the local geology. The beautiful landscape of the Welsh Marches is underlain by a rock sequence representing ten of the twelve recognised periods of geological time (10 out of 13 if the Tertiary is subdivided into two periods).