Geochemical markers of the North Flinders Reef (Coral Sea, Australia) Porites sp. coral cores

North Flinders Reef in the Coral Sea (Australia) is located 150 km east of the Great Barrier Reef. A 3 m-long core of Porites sp. coral was extracted from the southern section of North Flinders reef in May 1992 (FLI01A) from approximately 5 to 10 m water depth by the Australian Institute of Marine Science (AIMS) using a hydraulic drill system. On the same trip, a long core (FLI02A) was extracted from the northwestern side of the reef. Once retrieved, the cores were rinsed with freshwater, sun-dried and stored on board the research vessel before sectioning at the Australian Institute of Marine Science, before being cut lengthwise into 7 mm thick slices and X-rayed to reveal regular and well-defined annual density bands.In December 2017 a 0.5 m-long core (FLI05A) from 5 m water depth by a team of divers from James Cook University (Australia) and the University of Western Australia using a pneumatic air drilling system during a research cruise with MV Phoenix. All cores are stored in the core depository of at AIMS.The geochemical markers in yearly growth layers of the coral cores were ingestigated to define changes in temperature, water chemistry, chemicals from pollution and fertilisers, and other anthropogenic influences. Sample analyses included Radiocarbon (14C), Radiogenic isotopes (137Cs, 210Pb, 241Am, 239+240Pu), Spheroidal carbonaceous fly-ash particles (SCP), Pollution metal (Hg), Coral skeleton-bound stable nitrogen isotopes (CS-δ15N), Stable oxygen and carbon isotopes ( δ18O, δ13C), and Trace elements (Sr/Ca, Mg/Ca, Ba/Ca).Cores FLI01A and FLI05A were resampled in this study (see Zinke, et al. 2023) to annual resolution for the post-1940 period taking splits of the bimonthly samples for each individual year to obtain an annual sample of approx. 20–50 mg (FLI01A: 1940–1992 CE; FLI05A: 1988–2017 CE).

澳大利亚珊瑚海的北弗林德斯礁（North Flinders Reef）坐落于大堡礁以东150公里海域。1992年5月，澳大利亚海洋科学研究所（Australian Institute of Marine Science, AIMS）借助液压钻探系统，于该礁南部约5至10米水深处采集了一根长3米的多孔螅属（Porites sp.）珊瑚岩芯（编号FLI01A）。同次科考航次中，科研人员还在该礁西北侧采集了另一根长岩芯（FLI02A）。岩芯取回后，先用淡水冲洗、日晒干燥，随后在科考船上暂存，待返回澳大利亚海洋科学研究所后进行切割处理：将岩芯沿纵向切分为7毫米厚的切片，并通过X光扫描显现出规则清晰的年度密度层理。

2017年12月，由澳大利亚詹姆斯·库克大学与西澳大利亚大学组成的潜水团队，搭乘MV Phoenix号科考船开展航次调查期间，使用气动钻探系统在5米水深处采集了一根长0.5米的岩芯（FLI05A）。所有岩芯均存放于澳大利亚海洋科学研究所的岩芯库中。

本研究通过分析珊瑚岩芯年生长层中的地球化学标志物，以明确海水温度、水体化学组成、污染与化肥源化学物质及其他人为活动的影响变化。分析涵盖的样品指标包括：放射性碳（¹⁴C）、放射成因同位素（¹³⁷Cs、²¹⁰Pb、²⁴¹Am、²³⁹+²⁴⁰Pu）、球形碳质飞灰颗粒（Spheroidal carbonaceous fly-ash particles, SCP）、污染金属（Hg）、珊瑚骨骼结合态稳定氮同位素（CS-δ¹⁵N）、稳定氧与碳同位素（δ¹⁸O、δ¹³C）以及微量元素比值（Sr/Ca、Mg/Ca、Ba/Ca）。

本研究对FLI01A与FLI05A两根岩芯进行了重新采样（详见Zinke等，2023），针对1940年之后的时段以年分辨率开展分样：将每两月采集的样品按年份拆分，得到单年样品量约为20–50毫克（FLI01A覆盖公元1940–1992年；FLI05A覆盖公元1988–2017年）。