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A field guide to Barbados (Part 6): Central Barbados

Stephen K Donovan (The Netherlands) Stop 1. Waterford District, near Codrington Agricultural Station (approx. 59º 36’ 8” W 13º 6’ 49” N; Fig. 1) The area considered in the final part of this guide is outlined in A field guide to Barbados (Part 1): Introduction (Donovan & Harper, 2010, fig. 1e) and Fig. 1 in this article. As with other articles in this series, the starting point is Bridgetown. Fig. 1. Locality map showing the positions of Stops 1 to 6 in central Barbados. Only those roads relevant to this excursion are shown (after Donovan & Harper, 2005, fig. 12). This figure should be used in conjunction with the geological map of Poole & Barker (1983) and any tourist road map. Key: abc = ABC Highway; B = Bridgetown; 1 = Waterford district (Stop 1); 2 = Dayrells (Stop 2); 3 = Harrison’s Cave (Stop 3); 4 = Welchman Hall Gully (Stop 4); 5 = Horse Hill (Stop 5); 6 = Hackleton’s Cliff (Stop 6); coastline stippled. From the ABC Highway, turn southwest towards Bridgetown on Highway 3. In the area of the turnoff towards Codrington Agricultural Station (on the right), in the parish of St Michael, examine the road cutting, starting at the southwest corner and walking northeast. This is Stop 6 of Humphrey & Matthews (1986, p. 101), in the Middle Coral Rock, just above the First High Cliff and dated at 194,000 years old. The succession shows a range of reef-related biologically-determined facies (that is, sedimentary rocks … Read More

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A field guide to Barbados (Part 5): The Scotland District

Stephen K Donovan (The Netherlands) Stop 1. Chalky Mount (approximately 59º 33’ 15” W 13º 13’ 55” N; Fig. 1) The area considered in this part of the guide is outlined in Donovan & Harper (2010, fig. 1d) and Figs. 1 and 2. As with other articles in this series, the starting point is Bridgetown. Those wishing to examine the succession and structure of the Scotland District in considerably more detail than outlined below are referred to Speed (2002). This can be complimented by Patel’s (1995) discussion of the geomorphology. Readers are referred to the glossary in A field guide to Barbados (Part 2): The coastal geology of southeast Barbados Fig. 1 Locality map showing the positions of Stops 1 to 7 in the Scotland District of Barbados (after Donovan & Harper, 2005, fig. 11). Only those roads relevant to this excursion are shown. This figure should be used in conjunction with the geological map of Poole & Barker (1983) and any tourist road map. Key: C = Conset Point; H = Horse Hill; W = Welchman Hall; Stop 1 = Chalky Mount; Stop 2 = Bissex Hill; Stop 3 = Coconut Grove; Stop 4 = exposures on East Coast Road; Stop 5 = oil seep; Stop 6 = Bathsheba; Stop 7 = Bath Cliff; coastline stippled. Fig. 2 Geological map of the Scotland District of Barbados (after Donovan & Harper, 2005, fig. 2; Donovan, 2010, fig. 3; simplified after Speed, 2002, fig. 9). Key: open stipple = basal complex; … Read More

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A field guide to Barbados (Part 4): Bridgetown and the South Coast

Stephen K Donovan (The Netherlands) The area considered in this part of the guide is outlined in Donovan & Harper (2010, fig. 1C) and Fig. 1 of this article. As in other articles in this series, the starting point is Bridgetown. Fig. 1. Locality map showing the positions of Stops 1 to 5 on or near the south coast of Barbados (after Donovan & Harper, 2005, fig. 8). Only those roads relevant to this excursion are shown. This map should be used in conjunction with the geological map of Poole & Barker (1983) and any tourist road map. Key: A = Grantley Adams International Airport; abc = ABC Highway; C = Six Cross Roads; O = Oistins; 1 = the Barbados Museum, Bridgetown (Stop 1); 2 = South Point Lighthouse (Stop 2); 3 = Foul Bay (Stop 3); 4 = Woodbourne Oilfield (Stop 4); 5 = Chapel Quarry (Stop 5); coastline stippled.  Stop 1: The Barbados Museum The Barbados Museum and Historical Society was founded in 1933. Its museum occupies St Ann’s Garrison, a nineteenth century British military prison. It is situated in the parish of St Michael, southeast of the central part of Bridgetown, behind the Garrison Savannah racetrack. The museum has displays covering many aspects of Barbadian history and life, including natural history, prehistory and maps. The library is an important research resource, containing 5,000 books, monographs and articles on the culture and natural history of the island. Articles about the island’s natural history, culture and history are … Read More

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A field guide to Barbados (Part 3): Northern Barbados

Stephen K Donovan (The Netherlands) Stop 1: Arawak Cement Quarry The area considered in this part of the guide is outlined in Donovan & Harper (2010, Fig. 1b) and Fig. 1. As with other articles in this series, the starting point is Bridgetown. Drive north from the Bridgetown area on Highway 1, the main west (or leeward) coast road, which is constructed on the Lower Coral Rock and overlies superficial deposits. Fig. 1. Locality map showing the positions of Stops 1 to 4 in northern Barbados (after Donovan & Harper, 2005, fig. 7). Only those roads relevant to this excursion are indicated (including the track to Stop 4). This map should be used in conjunction with the geological map of Poole & Barker (1983) and any tourist road map. Key: C = Content; Ch = Checker Hall; G = Greenidge; T = Trents; 1 = Arawak Cement Quarry (Stop 1); 2 = Animal Flower Cave, North Point (Stop 2); 3 = limestone cliffs west of North Point (Stop 3); 4 = Cluff’s Bay (Stop 4); coastline stippled. The First High Cliff and the Middle Coral Rock are close by in the east (Speed & Cheng, 2004). This coast has been developed for tourism and has neither the magnificent sea cliffs of the east coast, nor the impressive Atlantic breakers seen in the previous excursion. To the west, two submerged barrier reefs, at 22m and 70m water depth, are separated from the coast by a submerged wave cut terrace (MacIntyre, 1967). … Read More

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A field guide to Barbados (Part 2): The coastal geology of southeast Barbados

Stephen K Donovan (The Netherlands) and David AT Harper (Denmark) Introduction This article is the second part of a field guide to Barbados, the first part of which is A field guide to Barbados (Part 1): Introduction. The areas visited by different the excursions outlined in Parts 2 to 6 of this guide are shown in Fig. 1. All itineraries commence from the Bridgetown area and the itinerary outlined in this part is rewritten after Donovan and Harper (2002). The words in italics and bold appear in the glossary at the end of the Part 1. Fig. 1. Relative positions of field excursions described in this field guide (after Donovan & Harper, 2005, fig. 5). (a) Southeast Barbados (Part 2). (b) North Barbados (Part 3). (c) South Barbados (Part 4). (d) Scotland District (Part 5). (e) Central Barbados (Part 6). Charles Taylor Trechmann DSc, FGS (1885-1964) (Fig. 2) was an anachronism, a twentieth century gentleman geologist and archaeologist. He was an amateur with sufficient private means to dedicate his time and use his scientific abilities to make an original contribution to his chosen field of study, an original thinker with a desire to use his observations to interpret broad geological phenomena. He devoted his time to research on Malta, Gibraltar, New Zealand and, particularly, northeast England and the Caribbean. He published over 80 monographs and research papers on geology and archaeology, including at least 40 on the Caribbean (Donovan, 2003, 2008, 2010a). Fig. 2. Charles Taylor Trechmann, DSc, FGS (1884-1964) … Read More

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A field guide to Barbados (Part 1): Introduction

Stephen K Donovan (The Netherlands) This is the first of six articles that will introduce the geology of the Antillean island of Barbados. It is an expanded and more detailed guide derived from two earlier publications (Donovan & Harper, 2005, 2009). The structure of the guide will include a summary of the geology of the island (in this part) and five, one-day field excursions for the geologically-biased tourist. These excursions will introduce the stratigraphy, structure and geological history of Barbados (Figs. 1 and 2), a small Antillean island shaped like a contorted teardrop, about 34km long by 24km at its widest. Fig. 1. The principal features of the geological history of Barbados summarised in a single section at Spring Bay, parish of St. Phillip, on the southeast coast. Professor David Harper (University of Copenhagen) is looking northwest, towards Ragged Point (Fig. 2) and admiring the angular unconformity between the allochthonous Palaeogene basal complex (=Scotland Beds) and the overlying autochthonous bedded limestones of the Pleistocene Coral Rock. A visitor to the island, who wants to undertake fieldwork, should hire a car. The only other reliable forms of transport are bus and taxi. While cheap, buses tend to stick to the main routes, particularly in the countryside. However, the size of the island means that localities are rarely more than a few kilometres from a bus stop. If money is no object, a taxi driver will be happy to drop you at a site in the morning and collect you at a … Read More

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Palaeontology and caves in Jamaica

Stephen K Donovan (The Netherlands). Although it has a rock record that only extends back to the Early Cretaceous, the geology of Jamaica is sufficiently diverse to satisfy most appetites (Donovan & Jackson, 2012a, b). It lies within the North Caribbean Plate Boundary Zone and displays a range of geological structures, commonly faults, both ancient and modern. There are about 25 Cretaceous inliers, from small to large, each including a sequence of volcanic and/or sedimentary rocks that are rarely metamorphosed. The half-graben Wagwater Belt in the east, flanking the western margin of the Blue Mountain inlier, is a Paleogene succession of terrestrial red beds, shallow to deep water siliciclastics and volcanics. These older rocks are draped by thick sequences of Eocene and younger rocks, which are mainly sedimentary (Robinson, 1994). Of the sedimentary rocks, limestones from the Cretaceous to the Quaternary are particularly widespread (Fig. 1), covering about two-thirds of the island’s surface. Although only subaerially exposed for about the last ten million years, these limestones have been strongly karstified under conditions of tropical high temperatures and seasonal extreme precipitation (Donovan, 2002). This has produced widespread, and magnificent, karst topography. Fig. 1. Simplified geological map of Jamaica, showing the principal stratigraphical units (after Donovan, 1993, fig. 1). Key: B=Blue Mountain inlier; C=Central inlier. Stratigraphy of principal Cenozoic units: granodiorite=Upper Cretaceous to Paleocene; Wagwater Formation, Newcastle Volcanics=Paleocene; Richmond Formation=Paleocene to Lower Eocene; Yellow Limestone Group=Lower to Middle Eocene; White Limestone Group=Middle Eocene to Upper Miocene; Coastal Group=Upper Miocene to Quaternary; alluvium=Quaternary. … Read More

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Geology of islands

 Stephen K Donovan (The Netherlands) Islands are attractive places to visit, not just for geologists. Nonetheless, for us, they provide three advantages that favour collecting and research in the Earth Sciences. One of the attractions of an island is its small size in comparison with continents. The corollary of this small size is its relatively long coastline. Assuming that our island is not the mound of sand with a palm tree so loved by cartoonists, a long coastline indicates abundant exposures of rock, commonly well-exposed and accessible. Second, because of their relatively small size, islands offer a limited possible area of outcrop. The island may be volcanic in origin, so you may have one (or a few) volcanoes and its deposits to map, log and sample, producing a self-contained study. A particular sedimentary deposit may be (probably will be) limited to a single island. If you want to determine the palaeontology or palaeoenvironments of this deposit, the only place it can be studied is on one island. To give one example (among many), the Middle Miocene Grand Bay Formation, exposed on the east coast of Carriacou in the Grenadines, Lesser Antilles, includes the only crinoid-rich deposits in the Caribbean Islands. I had been studying the few Antillean fossil crinoids for ten years until I went to Carriacou and the sum total of specimens I had collected until then could have rested, comfortably, in the palm of one hand. From Carriacou, I collected bags of crinoid-rich bulk sediment samples (Donovan and … Read More

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Windmills and building stones: Antigua, West Indies

Stephen K Donovan (The Netherlands), David AT Harper (UK) and Roger W Portell (USA) In his latest book, Ted Nield (2014) reflects on building stones and what they tell the geologist about where they are. Once upon a time, building stones in Britain were derived locally and told the informed observer something of the local geology (apart from, of course, the exotic stones imported for banks and office blocks). That is, they were built of local stone from the local quarry. Today, stone is imported from as far afield as China, where once they would have been derived locally by horse and cart or canal boat. One place where local stone is still used is Antigua in the Lesser Antilles. For example, Jackson and Donovan (2013) described an attractive, green chloritized tuff, which is used throughout the island as a bright and distinctive building stone. Many old structures in rural areas are still constructed of stone, such as walls, buildings (including ruins) and, the subject of this article, disused windmills. For a general introduction to the geology of Antigua, see Weiss (1994) or Donovan et al (2014). All major stratigraphic units are Upper Oligocene; the regional dip is to the northeast. Betty’s Hope The Betty’s Hope site, in the parish of Saint Peter in eastern Antigua (Fig. 1), is an open air monument administered by the Museum of Antigua and Barbuda. Fig. 1. Outline map of Antigua (redrawn and modified after Weiss, 1994, fig. 3), showing the principal geological subdivisions … Read More

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Rival theories by English amateurs: Matley, Trechmann and the geological origin of Jamaica

Stephen K Donovan (The Netherlands) The two most significant geologists to visit Jamaica and study its geology between the two World Wars were both British: Charles Alfred Matley (1866-1947) and Charles Taylor Trechmann (1885-1964). Both had active research programmes in Jamaica and the Antilles in the 1920s and 1930s, mainly on subjects that did not overlap, but the one geological concept on which they strongly disagreed was the one that underpinned all of their work – the geological evolution of the Caribbean basin. C A Matley Charles Matley (Fig. 1A) was a career civil servant and distinguished amateur geologist. He studied at the Birmingham and Midland Institute and the Mason Science College. The latter was incorporated into the new University of Birmingham in 1900. At Mason College, he was taught by Charles Lapworth, the father of the Ordovician System and one of the principal debunkers of Murchison’s assignment of the Scottish Highlands to the Silurian (Oldroyd, 1990). Matley’s principal field research while at Birmingham was on the Precambrian and Lower Palaeozoic of North Wales (for example, Matley, 1899, 1900, 1928), particularly Anglesey, work for which he was awarded a DSc by the University of London in 1902. Of particular relevance to his Jamaican research was his understanding of the geology of the Llyn Peninsula and Anglesey (McIlroy and Horák, 2006). Fig. 1. (A) Charles Alfred Matley (1866-1947), probably in about 1935 at the earliest (after Donovan, 2008, fig. 2). (B) Charles Taylor Trechmann (1884-1964), date of image unknown (after Donovan, … Read More

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