. Bulletin of the British Museum (Natural History), Geology. ORDOVICIAN TRILOBITES OF CENTRAL WALES 43 is situated approximately half-way between the well-known shelly Ordovician out- crops at Llandeilo (Williams 1948, 1953) and Shelve (Whittard 1931, 1940, 1940a, 1955-67). Due to the presence of volcanic and intrusive rocks, the Ordovician inlier contrasts strongly with the gentler topography of the surrounding Silurian strata. Although. Fig. 2. Map showing the Ordovician outcrops of Wales and the Welsh Borderland together with the main localities yielding shelly faunas. the intrusive and vol
. Bulletin of the British Museum (Natural History), Geology. ORDOVICIAN TRILOBITES OF CENTRAL WALES 43 is situated approximately half-way between the well-known shelly Ordovician out- crops at Llandeilo (Williams 1948, 1953) and Shelve (Whittard 1931, 1940, 1940a, 1955-67). Due to the presence of volcanic and intrusive rocks, the Ordovician inlier contrasts strongly with the gentler topography of the surrounding Silurian strata. Although. Fig. 2. Map showing the Ordovician outcrops of Wales and the Welsh Borderland together with the main localities yielding shelly faunas. the intrusive and volcanic rocks of the inlier are well exposed, the sedimentary rocks are rarely seen in continuous section. In spite of numerous streams, surprisingly few are sufficiently free from superficial deposits to provide more than isolated out- crops, thus limiting the knowledge of the sedimentary succession which ranges from Lower Llanvirn (murchisoni Zone) to basal Caradoc (gracilis Zone). The bulk of the material used for this study was collected by the author during the tenure, at the Queen's University of Belfast, of a research studentship awarded by the Natural Environment Research Council to whom I am grateful for financial. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). London : BM(NH)
Size: 1407px × 1775px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
