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Authors

Charles Keyes

Document Type

Research

Abstract

Recent marked tendency shown in Europe especially to give taxonomic rank comparable to geological period, Carbonic, Cretacic, and the like, to rocks older than those of Cambric age, and to designate the rock column represented Precambian appears to be, in this country at least, a notably retrogressive movement. It parallels the situation a century ago when Wernerians were possessed with jumbling together all rocks beneath those of Cretacic age, as we know them today, under the title of the Transition Class. Out of the latter speedily take on form six great systems. Thus, late delimitations of Precambrian imply its recognition as having Systemic or Periodic rank, a rank much too low.

Publication Date

1929

Journal Title

Proceedings of the Iowa Academy of Science

Volume

36

Issue

1

First Page

277

Last Page

278

Copyright

© Copyright 1929 by the Iowa Academy of Science, Inc.

Language

en

File Format

application/pdf

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