摘要
梵净山九龙池剖面乃高山顶上的一个洼池剖面,深1m,未达到基岩。采样九块,孢粉分析获得孢粉2942粒,有57个科属。以木本花粉为主,草本花粉及蕨类孢子较少。自下而上划分为4个孢粉组合带。反映出古植被变化是以常绿阔叶树为主的常绿、落叶阔叶混交林—以落叶阔叶树为主的常绿、落叶阔叶混交林—落叶阔叶林—以松、栎为主的针阔叶混交林及喜冷湿的莎草较多。古气候变化由温暖湿热—温暖—温暖偏凉—温暖偏凉湿。其地质时代经^(14)C测定为5000年来的中全新世大西洋期—中全新世亚北方期。
Fanjing Mountain is the main peak of Willing Mountain Chains, which is located in the northern part of Guizhou Plateau and is the watershed between Wujiang River System and Yuanjiang River System. Its top height is 2493.8m above sea level. The mountain is high and the valley is low with the relative height being about 2000m, forming a geo-morphology of mid-mountain and narrow valley. Jiulongchi is located in a mountain depression about 1.5km SSW of the top ( 2212.7m above sea level) of Fanjing Mountian. Jiulongchi Section is about 1 m thick and from lower to upper it can be divided into five beds, which are mainly made up of black clay, grey clay, grey subclay, yellow subelay and black humus soil, etc. From nine sporo-pollen samples collected, the obtained 2942 sporo-pollen grains separately belonging to 57 families and genera, with woody Plants more but herbs and pteridophyta less, can be divided from lower to upper into four sporo-pollen assemblage zones:
ZONE 1 (80-100cm deep) : The woody plant pollens make up 86.5-92.5%, with Quercus glauca 36.4-39.3% and Quercus 8. 2-11.9%, and the herb pollens make up 3,2-4.8% and Pteridophyta spores 3.9-10.3%, belonging to a mixed evergreen deciduous broad-leaved forest with evergreen broad-leaved trees in majority. The climate was warm -moist-hot.
ZONE 2 (50--80cm deep) : The woody plant pollens make up 81.3-89.5%, with Quercus 28.9-38.9% and Quercus glauca 9.8-21.6%, belonging to a mixed evergreen deciduous broad-leaved forest with deciduous broad-leaved trees in majority. The climate was warm--hot--warm.
ZONE 3 (30-50cm deep ) :The woody plant pollens decrease, making up 40.4-47.1%, with Quercus 20. 1- 25. 9% , Salix 4. 3-7. 2%, Betulaceae and Juglans etc. in majority, the herb pollens makr up 5.3-9.1%, with Composite, Artemisia and Graminae, etc. in majority, and the Pteridophyta pollens suddenly rise up to 47.5-50.5%, with Athyriaceae and polypodiaceae, etc. in majority, belonging to a mixed broad-leaved forest with deciduous broad-leaved trees in majority. The climate was warm-warm-cool.
ZONE 4 (20-30cm deep) :The woody pollens again decrease but the Pinus pollens of coniferous trees rise up to 19.7%,the Tsuga pollens make up 0. 5% , the pollens of broad-leaved trees only make up 16.2%, with Athyriaceae and Polypodioceae, etc. in majority, and the herb pollens suddenly rise up to 51.9%, with Cyperaceae 40.9% and Pteridophyta 11.6%, belonging to a mixed coniferous and broad-leaved forest with Pinus and Quercus trees in majority. The moist land of the forest margin depression was expanded, suitable to the growth of Cyperaceae. The climate was warm - cool.
To sum up, the palaeovegetation has undergone several stages of change: the mixed evergreen deciduous broad-leaved forest with evergreen broad-leaved trees in majority-the mixed evergreen deciduous broad-leaved forest--the mixed coniferous and broad-leaved forest with Pinus and Quercus trees in majority and with more Cyperaceae in a cool-moist climate.
The palaeoclimate was warm, moist, hot--warm--warm, cool--warm, cool, moist, and the geological age, measured by 14C, belonged to the 5000-year-old Mid-Holocene At, lantic Phase-Subboreal Phase.
出处
《贵州地质》
1989年第2期110-116,共7页
Guizhou Geology
