Great Barrier Reef Coral and Halimeda Cd/Ca Ratios: Holocene Paleochemical Records

将测定澳大利亚大堡礁全新世珊瑚礁和生物礁中珊瑚和文石沉积绿藻haalimeda中的镉钙比例。目标是：(1)确定外大陆架珊瑚礁的Cd/Ca比值的全新世变化，包括在代表个别珊瑚礁背风至迎风环境的岩心中从8500 ybp到现在的记录，以及跨越一系列纬度的珊瑚礁；(2)通过对比当代珊瑚和部分历史珊瑚，确定全新世大堡礁珊瑚Cd/Ca比值的季节性变化；(3)确定大堡礁海藻类生物礁全新世以来Cd/Ca比值的变化。2000年（同一纬度珊瑚礁形成前）至现在；(4)通过对珊瑚礁和水母的Cd/Ca记录进行解释，验证营养供应变化在控制大堡礁全新世珊瑚礁和生物礁生长中的作用。将认真注意识别和隔离由于陆地而非海洋影响和变化而产生的微量元素信号。石墨炉和火焰原子吸收分光光度法将用于测定Cd/Ca、Mn/Ca、Sr/Ca和Mg/Ca比率；x射线衍射光谱学将用于确定矿物学。

Cadmium.to.calcium rations will be determined in corals and in the aragonite.depositing green alga Halimeda in Holocene reefs and bioherms from the Great Barrier Reef, Australia. The objectives are: (1) to determine Holocene variations in Cd/Ca ratios in outer shelf coral reefs, including records from reef initiation 8500 ybp to the present in cores representing leeward to windward environments in individual reefs and from reefs spanning a range of latitudes; (2) to determine variations in seasonality in Cd/Ca ratios in Holocene Great Barrier Reef corals, comparing contemporary and selected historical corals; (3) to determine Holocene variations in Cd/Ca ratios in Great Barrier Reef Halimeda bioherms, from initiation (.2000 y before coral reef initiation in the same latitude) to the present; and (4) to interpret Cd/Ca records from coral and Halimeda to test hypotheses about the role of changing nutrient supply in controlling Holocene reef and bioherm growth in the Great Barrier Reef. Careful attention will be given to identifying and isolating trace element signals due to terrestrial, rather than oceanographic influences, and to alteration. Graphite furnace and flame atomic absorption spectrophotometry will be used to determine Cd/Ca, Mn/Ca, Sr/Ca, and Mg/Ca ratios; X.ray diffraction spectroscopy will be used to determine mineralogy.