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I.—The Mineral Condition of the Calcium Carbonate in Fossil Shells
Published online by Cambridge University Press: 01 May 2009
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A recent paper by Mr. A. R. Horwood on “Aragonite in the y Middle Lias” raises again the question of the condition of the calcium carbonate in fossil shells. Mr. Horwood speaks (p. 176) of Jurassic shells as being “preserved in aragonite”, and quotes Dr. Sorby as being of the same opinion. But is Mr. Horwood sure that his shells are still in the aragonite condition? Sorby, when he writes of “aragonite shells”, means as a rule shells that were formed of aragonite at the time of the death of the originating animal; but he describes how, in many of our fossiliferous rocks, such shells are represented either by hollow spaces or by pseudomorphs in granular caleite. He points out that oolitic grains, originally consisting of aragonite, have similarly been changed into calcite, the more stable form of calcium carbonate. Some oolitic grains, however, were thought by him to have consisted of calcite from the outset. Doelter, after summing up Linck's researches on calcite and aragonite, states that calcareous oolites now consist of calcite; and we have no doubt that the “recrystallized aragonite concretions”, quoted by Mr. Horwood from Sorby, were held by Sorby to be at the time of examination in the calcite state.
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References
page 49 note 1 GEOL. MAG., 1910, p. 173.Google Scholar
page 49 note 2 Quart. Journ. Geol. Soc, vol. xxxv, Proceedings, pp. 65, 83, 93, etc., 1879.Google Scholar
page 49 note 3 Ibid., p. 68.
page 49 note 4 On the relative stability of caleite, see Foote, H. W., “Über die physikalischehemischen Beziehungen zwischen Aragonit und Calcit”: Zeitschr. für physikalische Chemie, Bd. xxxiii, p. 753, 1900.Google Scholar
page 49 note 5 Petrogenesis, p. 225.Google Scholar
page 49 note 6 “Über die heteromorphen Zustände der kohlensauren Kalkerde”: Abhandl. Akad. d. Wiss., Berlin, 1856, p. 1, and 1858, p. 63.Google Scholar Rose's first researches on the mineral forms of calcium carbonate were published in Poggendorff's, Annalen, Bd. xlii, p. 353, 1837.Google Scholar A French translation, containing a correction of a slip on p. 361 of the German paper, appeared in the Annales des Mines, 1837, p. 611.Google Scholar
page 50 note 1 “Ueber die Veränderungen, welche gewisse Mineralien, etc.”: Poggendorff's, Annalen, Bd. xi, p. 177, 1827; also Trans. Roy, . Soc. Edin., 1827.Google Scholar
page 50 note 2 2 Op. cit., 1856, p. 1.
page 50 note 3 “Beiträge zur Kenntnis des kohlensauren Kalkes”: Ber. naturforsch. Gesell. Freiburg i. Br., Bd. xv, p. 1, 1907.Google Scholar
page 50 note 4 Poggendorff's, Annalen, Bd. xlii, p. 363, 1837.Google Scholar
page 51 note 1 Quart. Journ. Geol. Soc, vol. xxxv, Proceedings, p. 59. See also Rose, , Abhandl. Akad. Wiss., Berlin, 1858, p. 68.Google Scholar
page 51 note 2 “On the Physical Characters of Calcareous and Siliceous Sponge-spieules and other Structures”: Sci. Proc. Soc, R. Dublin., vol. iv, p. 390, 1885.Google Scholar
page 51 note 3 “The Aptychus”: GEOL. MAG., 1894, p. 457.Google Scholar
page 51 note 4 Op. cit., p. 60. Cf. Cornish & Kendall, “On the Mineralogical Constitution of Calcareous Organisms”: GEOL. MAG., 1888, p. 71.Google Scholar
page 52 note 1 “Über die heteromorphen Zustände der kohlensauren Kalkerde”: Abhandl. Akad. d. Wiss., Berlin, 1858, p. 80.Google Scholar
page 52 note 2 Mineralogie, 1884, p. 418.Google Scholar
page 52 note 3 “On the Dissolution of Aragonite Shells in the Coralline Crag,” GEOL. MAG., 1883, p. 497;Google Scholar and “On the Mineralogieal Constitution of Calcareous Organisms”, ibid., 1888, p. 68.
page 52 note 4 Op. cit., p. 77.
page 52 note 5 Centralblatt für Min., etc., 1901, p. 577,Google Scholar and Ber. naturforsch. Gesell. Freiburg i. Br., Bd. xv, p. 20, 1907.Google Scholar
page 53 note 1 Aids in Practical Geology, 6th ed., p. 36.Google Scholar
page 53 note 2 GEOL. MAG., 1883, p. 497.Google Scholar
page 53 note 3 Abhandl. Akad. Wiss., Berlin, 1858, p. 80.Google Scholar
page 53 note 4 Op. cit., GEOL. MAG., 1888, p. 72.Google Scholar
page 55 note 1 Quart. Journ. Geol. Soc, 1879, Proceedings, p. 83Google Scholar.