(Table 1) Carbon and nitrogen analyses of samples from DSDP Leg 64 Holes

We analyzed Leg 64 sediments for total carbon and acid-insoluble (organic) carbon using a LECO WR-12 Analyzer. We first dried the 3-5 cm**3 sediment samples at 105°-110°C (some shallow sediments used for the C-H-N analyses were dried at 45-55 °C) and then ground them to a homogeneous powder. The ground sediment was redried and two samples (0.1 g and 0.5 g) were then weighed in LECO clay crucibles. The 0.5-g sample was acidified with a 10% hydrochloric acid solution and then washed with distilled water. We then dried and analyzed the sample for acid-insoluble carbon, listed in Table 1 as "organic" carbon. The 0.1-g sample was analyzed for total carbon without further treatment. If the result showed less than 10% CaCO3, we analyzed an additional 0.5-g sample for greater accuracy.本研究使用LECO WR-12型分析仪，对第64航次（Leg 64）的沉积物样品开展总碳与酸不溶（有机）碳含量分析。首先将3~5立方厘米的沉积物样品置于105~110℃下烘干（部分用于碳-氢-氮（C-H-N）分析的浅表层沉积物则在45~55℃下烘干），随后研磨为均匀粉末。研磨后的沉积物经再次烘干后，称取0.1g与0.5g两份样品至LECO瓷坩埚中。将0.5g样品用10%盐酸溶液酸化，随后用蒸馏水冲洗，烘干后开展酸不溶碳含量分析，该结果在表1中记为"有机碳"。0.1g样品无需额外前处理，直接开展总碳含量分析。若检测结果显示碳酸钙（CaCO₃）含量低于10%，则额外称取一份0.5g样品进行分析以提升检测精度。