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Tyndall Group

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Journal Article
Journal: Economic Geology
Published: 01 August 2001
Economic Geology (2001) 96 (5): 1073-1088.
... and hyaloclastic dacites associated with interbedded carbonates and calcareous volcaniclastic sandstones located at the Mount Read Volcanics Tyndall Group-Central Volcanic Complex boundary. The alteration zone forms a subvertically dipping tabular sheet over 3 km in length and between 10 and 100 m in width...
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Journal Article
Journal: Economic Geology
Published: 01 May 1992
Economic Geology (1992) 87 (3): 597-619.
... alteration studies.Three calc-alkaline suites (one extending to shoshonitic compositions) and two tholeitiic suites have been distinguished within the Mount Read belt. Suite I is voluminous and includes the Eastern sequence, Central Volcanic Complex, Tyndall Group, the intrusive quartz-feld-spar porphyries...
Journal Article
Journal: Economic Geology
Published: 01 August 2001
Economic Geology (2001) 96 (5): 1089-1122.
... of the Owen Group. Small lead-zinc-rich massive sulfide lenses, together with lenses of fossil-rich limestone, characterize the exhalative zone, which is hosted within submarine volcaniclastic breccias and sandstones in the basal part of the late Middle Cambrian Tyndall Group at Comstock. The upper part...
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Journal Article
Journal: Economic Geology
Published: 01 May 1992
Economic Geology (1992) 87 (3): 564-586.
... to active felsic volcanism which produced widespread crystal- and pumice-rich mass-flow deposits of the Southwell Subgroup and Tyndall Group. GeoRef, Copyright 2006, American Geological Institute. Abstract, Copyright, Society of Economic Geologists 1992 ...
Journal Article
Journal: Economic Geology
Published: 01 July 1997
Economic Geology (1997) 92 (4): 438-447.
... at the base of the Tyndall Group, a sequence of rhyolite lavas and crystal-rich volcaniclastics. Fossiliferous sediments and welded ignimbrites within this group are indicative of a local shallow-water environment. Mineralization occurs in a conformable package of altered rocks in the footwall of a major...
Journal Article
Journal: Economic Geology
Published: 01 March 2015
Economic Geology (2015) 110 (2): 445-468.
... to underlie the Mount Read Volcanics. Magmatism in the central Mount Read Volcanics lasted at least 12.7 m.y., from 506.8 ± 1.0 Ma for a massive dacite unit in the lower part of the Central Volcanic Complex to 496.0 ± 0.9 Ma for a welded ignimbrite in the lower Tyndall Group. Together with previous age...
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Journal Article
Journal: Economic Geology
Published: 01 August 2004
Economic Geology (2004) 99 (5): 987-1002.
...Nicholas C. Williams; Garry J. Davidson Abstract The Basin Lake copper-gold prospect lies in western Tasmania’s Mount Read Volcanics and is hosted in a series of calc-alkaline andesites, quartz-feldspar porphyries, mudstones, carbonates, and sandstones between the Tyndall Group and the Central...
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Journal Article
Journal: Economic Geology
Published: 01 August 1993
Economic Geology (1993) 88 (5): 1176-1197.
... of magmatic zircons and hornblendes, respectively, from different parts of the Mount Read Volcanics yields a concordant age of 502.6 + or - 3.5 Ma (1Sigma ), which constrains the time of volcanogenic massive sulfide mineralization. The Comstock Tuff from the Tyndall Group in the upper part of the volcanic...
Journal Article
Published: 22 December 2016
Journal of the Geological Society (2017) 174 (3): 509-521.
... Cretaceous Chalk Group of Hampshire, UK, and a newly compiled 3D geological model that maps subsurface extent. The geological model provides rock volumes, and these are compared with exposure and outcrop area, sampling proxies that have often been conflated in previous studies. The extent to which exposure...
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Journal Article
Journal: Paleobiology
Published: 01 May 2019
Paleobiology (2019) 45 (2): 347-362.
...Thomas L. Stubbs; Michael J. Benton; Armin Elsler; Albert Prieto-Márquez Abstract The hadrosaurids were a successful group of herbivorous dinosaurs. During the Late Cretaceous, 100 to 66 million years ago, hadrosaurids had high diversity, rapid speciation rates, and wide geographic distribution...
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Journal Article
Published: 03 May 2017
Journal of the Geological Society (2017) 174 (5): 793-802.
... the Weng'an Biota includes forms that could be animals, none can currently be assigned to this group with confidence. Nonetheless, the biota offers a rare and valuable window on the evolution of multicellular and soft-bodied organisms in the prelude to the Cambrian radiation. 21 11 2016 28 02 2017...
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Journal Article
Journal: Paleobiology
Published: 01 November 2018
Paleobiology (2018) 44 (4): 620-637.
... and Rayfield 2006 ; Cantalapiedra et al. 2013 ; Button et al. 2014 ; Gill et al. 2014 ; Stubbs and Benton 2016 ). The K-Pg mass extinction event was one of the most severe in the history of life, leading to the complete extinction of nonavian dinosaurs, among many other groups. There is now abundant...
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Journal Article
Published: 01 January 2014
American Mineralogist (2014) 99 (1): 128-138.
... to the center of symmetry, the EBSD cannot distinguish if it is the Ψ- or Φ-octahedra that comprise the etch pit walls. Kudoh et al. (2006) speculated that the orientation A with the Φ-octahedra-terminated steps is more stable because the OH groups not bound to the underlying TOT layer (OH groups above...
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Journal Article
Published: 11 July 2018
Quarterly Journal of Engineering Geology and Hydrogeology (2019) 52 (3): 320-325.
... with idealized sections showing typical relationships between the periglacial features. Two of the features identified in the model include relict shear surfaces on valley slopes with cambering and gulls identified near the crest of slopes. The publication by the Geological Society Engineering Group provides...
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Journal Article
Journal: GSA Bulletin
Published: 01 September 2014
GSA Bulletin (2014) 126 (9-10): 1317-1339.
...Wolfgang Stinnesbeck; Eberhard Frey; Luis Rivas; Judith Pardo Pérez; Marcelo Leppe Cartes; Christian Salazar Soto; Patricio Zambrano Lobos Abstract Remnants of ophthalmosaurid ichthyosaurs recently discovered in the vicinity of the Tyndall Glacier in the Torres del Paine National Park of southern...
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Journal Article
Journal: Paleobiology
Published: 22 May 2017
Paleobiology (2017) 43 (3): 435-462.
... ; Button et al. 2014 ), and tooth microwear studies have also demonstrated dietary divergence between sympatric “broad-crowned” and “narrow-crowned” taxa (Fiorillo 1991 , 1998 ; Upchurch and Barrett 2000 ; Whitlock 2011 ). Statistical comparison was made between these groups to test...
Series: Geological Society
Published: 01 January 2017
DOI: 10.1144/SP448.16
EISBN: 9781786202932
... of Ediacaran macrofossils made by Martin Brasier as he sought to better understand the Ediacaran biota. Drawing the specimens in detail provided detailed insights into their morphology. ( a ) Vinlandia antecedens and ( b ) Beothukis mistakensis from the Conception Group of Newfoundland, Canada. ( c...
Series: Geological Society
Published: 01 January 2017
DOI: 10.1144/SP448.3
EISBN: 9781786202932
... of their behavioural repertoire and have complex nesting, nest-tending and brooding behaviours ( Guggisberg 1972 ), but exhibit a relatively low EQ. Fig. 10. Encephalization quotients (EQ) estimated across a range of dinosaur clades/groupings. Extant crocodilians represent the reference marker (EQ=1.0...
Image
Photograph looking west at the Libbey Glacier fault across the <b>Tyndall</b> Glac...
in > Geosphere
Published: 01 February 2012
Figure 8. Photograph looking west at the Libbey Glacier fault across the Tyndall Glacier. Location is in Figure 3 . This outcrop was only observed from across the Tyndall Glacier, and the rocks in the hanging wall could be Cretaceous Yakutat Group mélange (K ym ) or sedimentary rocks
Journal Article
Journal: Paleobiology
Published: 15 December 2016
Paleobiology (2017) 43 (1): 15-33.
...Jamie A. MacLaren; Philip S. L. Anderson; Paul M. Barrett; Emily J. Rayfield Abstract Morphological responses of nonmammalian herbivores to external ecological drivers have not been quantified over extended timescales. Herbivorous nonavian dinosaurs are an ideal group to test for such responses...
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