摘要
昆仑山垭口羌塘组和三岔河组的孢粉分析表明 ,羌塘高原的干旱环境在早更新世时已经确立 .孢粉反映的古气候以干湿变化为主 ,冷暖变化不明显 ,可能与青藏高原隆起有关 .在 2～ 1.8MaBP ,羌塘高原的古植被是以麻黄、藜科、蒿等为主的荒漠或草原荒漠植被 ,1.8～ 1.3MaBP气候变得比较温和稍湿 ,古植被演变成草原植被 ,在 1～ 0 .6 8MaBP ,本区在构造抬升和冰期气候控制之下植被极不发育 .0 .6 8～ 0 .6 5MaBP可能为一小间冰段 ,古植被为蒿、藜科、麻黄和众多草本植物组成的草原植被 ,羌塘组和三岔河组缺失 6 5 0～ 35 0kaBP的沉积 ,可能仍为荒漠植被 .倒数第二次间冰期时期 ,在三岔河组的沟谷里可能生长着云、冷杉组成的暗针叶林 .随后 ,古气候明显变干 ,针叶林消失 ;6 0kaBP之后 ,气候进一步变干 。
The pollen analysis of the layers of Qiangtang and Sanchahe groups in a saddle of the Kunlun Mountains shows that a dry environment had been come into in the Early Pleistocene in the Qiangtang Plateau. The pollen assemblages show that change in dryness was dominant rather than change in temperature, which could relate to the lift of the Tibetan Plateau. During 2～1.8 Ma BP, the vegetation was the desert or desert grassland consisted of Ephedra , Chenopodiaceous and Artemisia in the plateau. During 1.8～1.3 Ma BP, the climate changed into temperate and moist, the vegetation changed into grassland, and during 1.0～0.68 Ma BP, the vegetation developed badly due to tectonic lift and ice age climate in the plateau. During 0.68～0.65 Ma BP, the climate was in a little interglacial stage, and the vegetation was grassland consisted of Artemisia , Chenopodiaceous, Ephedra and many other herbs. The sediment of 0.65～0.35 Ma BP was missed in the layers of Qiangtang and Sanchahe groups. It is inferred that the vegetation was still the desert controlled by the ice age climate in this period. In the second interglacial stage from the last (0.35～0.15 Ma BP), there was the dark coniferous forest consisted of Piceas and Abies in the gullies and valleys when the layer of Sanchahe group deposited. Afterwards, climate changed to dry obviously, the coniferous forest disappeared (0.15～0.06 Ma BP). After 60 000 a BP, the climate further changed to dry and the vegetation changed to desert again.
出处
《冰川冻土》
CSCD
北大核心
2001年第4期407-413,共7页
Journal of Glaciology and Geocryology
基金
国家"八五"攀登计划青藏项目
国家自然科学基金项目 ( 4 98310 80
40 1710 95 )资助
