Awheel in Edwardian Bedfordshire: A 1905 Geologists’ Association cycling excursion revisited and contextualised

Most of the excursions organised by the Geologists’ Association in the late 19th C. and early 20th C. were essentially pedestrian in nature. However, around the turn of the 20th C. and up to the Great War (1914–1918), the Association experimented with either specific cycling-based excursions or those that accommodated the needs of cyclist excursionists. At the time, the Association, with its London base, was ideally placed to employ the railway network as the basis for its excursions. Railways were then the principal mode of transport for middle- and long- distance journeys and were increasingly promoting suburban expansion, creating potential new field excursion areas. The railways catered for those pedestrian excursionists and cyclists who wished to venture further afield from London than was previously possible on a day- or half- day trip. The notices and reports of excursions published by the Association are examined and critiqued. The cycling excursions are examined and contextualised within a combined technological and socio-historical framework; parallels are drawn with today. A re-examination of the excursions also provides a benchmark, useful for geoconservation purposes, of the availability and accessibility of historical geosites. It can underpin new self-guided geotrails suitable for use by a wider audience than traditional geological excursionists. These various themes are explored through the consideration of a specific 1905 excursion to Bedfordshire from which general conclusions are drawn.     

The Arab Geologists＇ Association（AGA）

The Arab Geologists Association (AGA) is a non-governmental pan-Arab geological organization founded in 1975 by geological commissions, i.e., geologists unions, geological societies, representing nine Arab countries, namely, Egypt, Palestine, Morocco, Jordan,Libya, Sudan, Lebanon, Tunisia and Iraq. Organizations of geologists in Syria and Yemen joined the Association shortly after.     

Comment on “Structural geology of the Upper Cretaceous Chalk Central Mass,Isle of Wight,UK” by Rory Mortimore. Proceedings of the Geologists’ Association,vol. 122 (2), 2012, pp. 298–331

The Chalk Group of the Central Downs of the Isle of Wight forms a relay ramp between two major inverted extensional faults. Mortimore (2011) presented a structural model of this key area based on a geological map constructed from detailed logging of a limited set of exposed sections. The area has been recently mapped at 1:10,000 scale by the British Geological Survey. Our interpretation of the geological structure differs significantly from that proposed by Mortimore, and suggests that Chalk has relatively uniform dips that progressively steepen towards the hanging wall of the E-W oriented basement faults. However, a suite of mapped extensional faults indicates an element of differential movement or transpression along the main basement structures.     

Geological history of the Sibumasu Block in Peninsular Thailand: report of a Geologists’ Association Field Meeting in 2007

It is widely accepted that Thailand consists of two principal blocks or terranes, both of Gondwana origin, which collided and fused in the Late Triassic. The western of the two is the Sibumasu Block, and the purpose of this field meeting was to examine Peninsular Thailand where the succession reveals the nature of Sibumasu's Late Palaeozoic rifting from Gondwana in the context of the overall Phanerozoic history of this block. Sedimentary rocks ranging from Cambrian to Miocene crop out in Peninsular Thailand, as well as granite plutons which are aligned in N-S chains, the western chain of Cretaceous–Palaeogene age and those further east of Triassic age. Of particular importance in that history was the NNE-SSW Khlong Marui Fault belt which coincides with the conspicuous bend of the Peninsula; it formed the (present day) eastern boundary of a Late Palaeozoic rift and has been active intermittently since.     

Reply to ‘Comment on: “Establishing the Late Pleistocene-Holocene sedimentation boundary in the southern North Sea using OSL dating of shallow continental shelf sediments” by L. Alappat,A. Vink,S. Tsukamoto,M. Frechen,Proceedings of the Geologists’ Association 121 (2010), 43–54’ by B. Mauz

The major concerns in the correspondence of Mauz (2012) was the correction applied for the calculation of cosmic dose in response of changing sea level in the past and statistical parameters used as well as the selection of MAM. A better approach is discussed in this note for the calculation of cosmic dose over a variable time span of rising sea level with the help of established sea level curves in the area. The selection of MAM-3 for the estimation of final De's are discussed in the article. The comments by Mauz (2012) have been helpful in rectifying some confusions that might have arisen in the original article of Alappat et al. (2010). However, some comments were merely speculative in nature and made by ignoring the statements that have been clearly mentioned in the article. After addressing various concerns of Mauz (2012), the results show that the variation in the final age due to this is small and within the uncertainty for all the samples.