ON THE SO-CALLED DANIAN s. I. OR DANO-MONTIAN OF AUTHORS
A b s t r a c t The expansion of the term Danian to include the Montian as its upper substage in a Danian s.l., a Montian s.l., or a Dano-Montian stage is unwarranted and does not conform with the original definitions af these terms. The Montian, as originally defined by DEWALQUE (1868), is proved t...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.525.3909 http://2dgf.dk/xpdf/bull17-01-103-111.pdf |
| Summary: | A b s t r a c t The expansion of the term Danian to include the Montian as its upper substage in a Danian s.l., a Montian s.l., or a Dano-Montian stage is unwarranted and does not conform with the original definitions af these terms. The Montian, as originally defined by DEWALQUE (1868), is proved to be a junior synonym of the Heersian (DUMONT, 1851), and planktonic Foraminifera in the latter stage represent a particular evolutionary stage in the development of this group which necessitates its separate treatment. DISCUSSION The prolonged controversy surrounding the stratigraphical position of the Danian has been almost settled by its assignment to the base of the Tertiary system, as the oldest stage of the Paleocene series (see discussion by the present writer 1963, 1966 and by BERGGREN 1962, 1964). Never-theless, the upper boundary of this stage is still much disputed, differently interpreted and difficult to decide. The difficulty has been mainly ex- |
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