浙北嘉湖平原沉积环境与土壤发育的探讨

APPROACH ON SEDIMENTARY ENVIRONMENTS AND SOIL DEVELOPMENT IN JIA HU PLAIN OF THE NORTHERN ZHEJIANG PROVINCE

浙北嘉湖平原发育,深受全新世中,后期沉积环境所制约。本文以该区分布最广的四个水稻土土属(湖成白土田、黄斑田、小粉田、青紫泥田)为研究对象,从颗粒参数、孢粉微体古生物组合、矿物成分、粘粒矿物、^(14)C、古遗址等方面的测定、分析推断,把本区沉积环境类型概分为滨湖相、陆相、海陆交互相、湖沼相四类。再进一步把沉积环境与土壤发育联系起来研究,以揭示本区几种水稻土的分布规律、形成特点和基本属性。

Jia hu plain is looated at the lower Yangtse River Delta. paddy soils occupy about 88% of the cultivated lands. Historically, most of the paddy soils were used for rice-wheat rotation. At the present time, large areas have been adopted for rice-rice-barley (or rape) rotation. The present article deals with the interelation between Soil development and sedimentary environments in Holocene period. In order to study the sedimentary substances, We chose four kinds of representative paddy soils (lacustrine loamy albic paddy soil, silt-clayey yellow mottled paddy soil, silt. paddy soil, submgergic clayey paddy soil) as testing samples, dating of ^(14)C, distribution of ancient ruins, particle parameter analysis, combination of microfossil and spore-pollen, clay mineral and mineral composition test were used to indicate the kinds of sedimentary substances. The results obtained show that the formation of different paddy soils are deeply influenced by the sedimentary environments. There are four sediments ha the Jia hu plain, they are Tai hu lake coastal deposits, continental deposit's, marinecontinental deposits and lacustrine deposits respectively The different sediments affect significantly the distribution, characteristics and development of paddy soils.