Aquilapollenites 花粉グループと Normapolles 花粉グループ-その分布と層位学的意義-

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Two large angiosperm pollen groups, Aquilapollenites/Triprojectacites and Normapolles, are found in the late Cretaceous and early Palaeogene. Pollen grains referable to the Normapolles group, which is composed of more than 100 genera, first appeared during the Cenomanian. After their relatively leisured evolution during the Cenomanian, they diversified rapidly and attained to the maximal prosperity during the Santonian to Maastrichtian, but by the end of the Eocene they were virtually extinct. They extended to the two main provinces, 1)European-Turanian and 2)East North America. The former spread more widely to China(west of Long. ca.120° E in northern district and west of Long. ca. 100° E in southern district), Meghalaya district(India), NW Tunisia, Spitzbergen and Jan Mayen Ridge in the Maastrichtian and/or early Palaeogene, and the latter more extensively to a) Mississippi embayment area and b) area west of the axis of the Cretaceous epeiric seaway. North Atlantic Coastal Plain, Gulf Coast, and California (west San Joaquin valley) are, of corse, in the Normapolles province, but only a few Aquilapollenites pollen grains entered into these areas during the Maastrichtian and early Palaeogene. The Normapolles pollen appeared in Colorado, Wyoming, Montana and Alberta until the Campanian (until the Maastrichtian in Utah) and after that, the Aquilapollenites/Triprojectacites pollen flora supplanted it and flourished during the Campanian/Maastrichtian to Palaeocene. The Aquilapollenites/Triprojectacites pollen grains, which are morphologically compared with the pollen grains of the Loranthaceae and Santalaceae, appeared in Siberia, East China, Japan, Alaska, western North America, Arctic Canada, Greenland, Scotland (Mull Island), Barents Sea (Gusinaya Bank) etc. during the Santonian to Palaeocene/partially to Eocene. During the early Palaeogene, the Aquialpollenites and/or Pentapollenites pollen grains are found sporadically in Hungary, Germany, Belgium, France, Spain, western China in the Normapolles province. Besides, they occurred sporadically in Egypt, Senegal, Nigeria, Gabon, Bengal(NE India), Karikal(S India), Sarawak(Malaysia), and Sergipe (Brazil) during the late Upper Cretaceous or Palaeocene, and the Normapolles pollen grains are also found in Egypt and Senegal of Africa. Both the Normapolles and Aquilapollenites/Triprojectacites pollenfloras are very useful in palynostratigraphy, especially in the correlation of marine and non-marine sediments. The oculate pollen flora, which is composed of three genera with elliptical form, binigeminate aperture or flange ornamentation, occurred in company with the Aquilapollenites/Triprojectacites pollen flora in many cases during the Campanian to Palaeocene/partially to Eocene.
〔長崎大学教養部〕の論文

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高橋清
長崎大学名誉教授(元教養部長)

Aquilapollenites 花粉グループと Normapolles 花粉グループ-その分布と層位学的意義-

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