论文部分内容阅读
本文测定了西沙群岛永乐环礁现代鳞碎磲壳的碳、氧、锶同位素组成。碳、锶同位素组成是现以年为周期的规律性变化。碳同位素组成与碎磲的生长发育阶段、生长速率、共生藻类的产率及光照量有关。研究表明，碎磲有三个生长期，即幼年期、发育期和性成熟期。在这三个期，年增长速率为慢-快-慢，相应的碳同位素变化特点为小一大一小。锶同位素的周期性变化与碳同位素的周期性变化基本一致，即呈峰-峰相对和谷-谷相对的正相关关系。锶同位素对附近大陆的降雨量和河流排放量有灵敏的反映。
In this paper, the carbon, oxygen and strontium isotopic composition of the modern Sclerotium crus-galli shell in the Yongle Atoll of the Xisha Islands was determined. Carbon, strontium isotope composition is the annual cycle of regular changes. The composition of carbon isotopes is related to the growth and development stage, growth rate, the yield of symbiotic algae and light intensity. Studies have shown that there are three growth stages, namely juvenile, developmental and sexual maturity. In these three periods, the annual growth rate is slow - fast - slow, and the corresponding carbon isotope changes are characterized by small size and small size. The periodic variation of strontium isotopes is basically consistent with the periodic changes of carbon isotopes, that is, the relative positive correlation between peak-peak and valley-valley. Strontium isotopes of the nearby continent rainfall and river discharges are sensitively reflected.