花粉化石が示す古気温

概要

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Pollen fossils have an allochthonous character and have some difficulty in the identification at specific level. These problems make it difficult to estimate paleotemperature from pollen fossils. "Traverse effect" is found as a general rule between productions and sedimentations of pollen grains (Traverse, 1988). This Traverse effect will be the key to the solution of the problems for allochthonous pollen fossils. It will be possible to identify pollen taxa at specific level through the SEM observation. Two types of paleotemperature obtained from pollen fossils are presented in this paper. One type is relative paleotemperature estimated from palyno-flora in the offshore sediments, and the other is paleotemperature with scale estimated from specified pollen taxa in the coastal sediments. The continuous palyno-floras obtained from Neogene nearshore sediments are useful to establish the five pollen zones and they were used to estimate a relative paleotemperature curve. Pollen fossils of the mangrove plant occurred from middle Miocene coastal sediment in Toyama Prefecture, Central Japan are almost authocthonous and can be identified at a specific level by SEM observation. These palynological data indicate that the mean temperature in winter season in Toyama district during the middle Miocene was nearly 18℃ higher than the condition today.
日本古生物学会の論文
1993-06-30