Extracting data on palaeoclimatic from Himalayan pollen grains
- Autor(en)
- Khum-Narayan Paudayal, David-Kay Ferguson
- Abstrakt
In order to reproduce plants make pollen and spores. Since pollination is a risky business, these are often produced in immense quantities. The number may vary from tens of grains in the flowers of some insect pollinated plants to hundreds of thousands in wind-pollinated flowers. Those pollen which fail to target the ovary, get wafted or washed into sediments. Being resistant to decay the outer skin (exine) with its characteristic pattern is preserved. This enables the scientist to identify which plants were present at different times in the past and reconstruct former climates. Pollen grains from more than a hundred horizons in the late Pleistocene sediments of the intermontane Kathmandu Basin (Gokarna, Thimi, and Patan Formations; Yoshida and Igarashi, 1984) were studied using light microscope (LM) and scanning electron microscope (SEM). By examining pollen from living counterparts using the same techniques, it is possible to identify the fossils accurately. Pollen photomicrographs of some common pollen types are presented in this poster. Because of their key role in the vegetation, it is essential to recognize the different pine (Pinus) and oak (Quercus) species (Nakagawa et al., 1996). By plotting the present altitudinal ranges of all the genera present in a single geological horizon, it is possible to infer the height of the vegetation at the time. During the late Pleistocene a depression of the vegetation in the order of 1000 m is indicated. However, this does not allow for a 2 mm/year post-depositional tectonic uplift in the lesser Himalaya (Kizaki, 1994). Depending on the age of the sediments, this figure could be as high as 1100 m. Before this value can be accepted as absolute, surface samples must be analyzed in order to estimate the amount of anabatic (uphill) and/or katabatic (downhill) transport of pollen involved.
- Organisation(en)
- Institut für Paläontologie
- Journal
- Journal of Asian Earth Sciences
- Band
- 19
- Seiten
- 49-50
- Anzahl der Seiten
- 2
- ISSN
- 1367-9120
- Publikationsdatum
- 2001
- ÖFOS 2012
- 105118 Paläontologie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/44542e76-3822-46b7-81d0-57e52bac0622