广东三水Ⅱ级河流阶地的孢粉与环境初探

THE PALYNOLOGY AND ENVIRONMENT OF THE II RIVER TERRACE FROM SANSHUI OF GUANGDONG PROVINCE

据广东三水左田村Ⅱ级河流阶地的样品分析，发现孢子花粉５７种（科、属），其中蕨类植物孢子占孢粉总数的５７．５％，木本植物花粉占３５．４％，草本植物花粉占７．１％。样品中还含沟鞭藻和疑源类化石。Ⅱ级河流阶地形成于中更新世，是河流作用的结果，但受到海水的影响。大约在距今３０—４０×１０４ａ时，该区植物群以热带、亚热带植物为主，属亚热带常绿季雨林。可能因间冰期全球气候转暖，海平面上升导致海水沿珠江上溯而使该区受到影响。

Fifty-seven sporo-pollen types were found in the samples from the Ⅱ river terrace in Zhuotian Village, where the individuals of pteridophyta spores occupy 57. 5% of the flora, arboreal pollens 35. 4% and herbaceous pollens 7.1 %, while dinoflagellates and acritarchs were found in the samples. In the paper, it is considered that the Ⅱ river terrace in Sanshui of Guangdong Province was formed in Middle Pleistocene as a result of riverine action and was influenced by sea water. Three to four hundred thousand years ago, the flora was mainly composed of subtropical-tropical plants and belonged to the subtropical evergreen rainforest. The climate was hot and moist, and mean annual temperature was similar to the present. The raise of the sea level caused the sea water enter the inland along the Zhujiang River was probably due to the warmer climate during the inter-glacial period.