Bulletin Volume 208-212

Bulletin Volume 208-212

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 edition. Excerpt: ...formation scale called Niagara, Oriskany, Chemung, and Coal Measures. In the paper just cited it was shown that these portions of time duration are the measure of an actual power of endurance expressed by the organisms themselves. This power of endurance is undoubtedly an exceedingly complex fact, but it is recorded simply by the continued appearance of fossils with the same morphological characters. If the characters are of specific rank their endurance is of relatively short geological time; if the characters are generic they are repeated for a longer period of time, etc. These endurance values of the characters of organisms were spoken of as bionic. The general term chron was proposed as a designation for a division of geological time, and thus one is enabled to speak of geochron as the time duration expressed by formations, and biochron as the duration expressed by the life history of organisms. A definite and-independent value (i. e., independent of the formation scale) was given to the chronological terms hemera, epoch, period, era, eon by using the bionic or endurance quality of organisms as the measure of them. Thus hemera was to be measured by the endurance of the biouic equilibrium of a local faunule; epoch, by the endurance of species; period, by the endurance of genera; era, by the endurance of families; eon, by the endurance of orders. One other set of terms applies peculiarly to faunas. Fossil faunas express evidence of a certain amount of migration or shifting of place of habitation during their life history. Barrande spoke of colonies. Recurrence of faunas has been described. In case a marine fauna shifts upon the sea bottom during differential movements of the crust of the earth two results are possible--either the bionic...show more

Product details

  • Paperback | 326 pages
  • 189 x 246 x 17mm | 585g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236767470
  • 9781236767479