Supplemental Data for Climate of the Past article \"Equatorial Pacific Carbonate cycles, 0-5 Ma: stratigraphy, dissolution, and paleoproductivity\"@en

Coherent variation of CaCO3 burial is a feature of the Cenozoic eastern equatorial Pacific. Nevertheless, there has been a long-standing ambiguity whether changes in CaCO3 dissolution or changes in equatorial primary production might cause the variability. Since productivity and dissolution leave distinctive regional signals, a regional synthesis of data using updated age models and high-resolution stratigraphic correlation is an important constraint to distinguish between dissolution and production as factors that cause low CaCO3. Furthermore the new chronostratigraphy is an important foundation for future paleoceanographic studies. The ability to distinguish between primary production and dissolution is also important to establish a regional carbonate compensation depth (CCD). We report late Miocene to recent time series of X-ray Fluorescence (XRF) derived bulk sediment composition and mass accumulation rates (MAR) from eastern equatorial Pacific Integrated Ocean Drilling Program (IODP) Sites U1335, U1337, U1338 and Ocean Drilling Program (ODP) Site 849, and also report bulk density derived CaCO3 MAR at ODP Sites 848, 850 and 851. We use physical properties, XRF bulk chemical scans, and images along with available chronostratrigraphy to inter-correlate records in depth space. We then apply a new equatorial Pacific age model to create correlated age records for the last 8 Myr with resolutions of 1-2 kyr. Large magnitude changes in CaCO3 and bio-SiO2 (biogenic opal) MAR occurred within that time period but clay deposition has remained relatively constant, indicating that changes in Fe deposition from dust is only a secondary feedback to equatorial productivity. Because clay deposition is relatively constant, ratios of CaCO3 % or biogenic SiO2 % to clay emulate changes of biogenic MAR. We define 5 major Plio-Pleistocene Low CaCO3 % (PPLC) intervals since 5.3 Ma. Two were caused primarily by high bio-SiO2 burial that diluted CaCO3 (PPLC-2—1685-2135 ka, and PPLC-5—4465-4737 ka), while 3 were caused by enhanced dissolution of CaCO3 (PPLC-1—51-402 ka, PPLC-3—2248-2684 ka, and PPLC-4—2915-4093 ka). Regional patterns of CaCO3 % minima can distinguish between low CaCO3 caused by high diatom bio-SiO2 dilution versus lows caused by high CaCO3 dissolution. CaCO3 dissolution can be confirmed through scanning XRF measurements of Ba. […]碳酸钙（CaCO₃）埋藏的协同变化是新生代东赤道太平洋的典型特征。然而长期以来学界始终存在核心歧义：究竟是碳酸钙溶解作用的变化，还是赤道初级生产力的改变引发了这种变异性。由于生产力与溶解作用会留下特征鲜明的区域信号，因此利用更新后的年龄模型与高分辨率地层对比开展数据区域综合研究，是区分“溶解作用”与“生产力”这两个导致碳酸钙含量偏低的关键因素的重要约束手段。此外，新建立的年代地层学框架也是未来古海洋学研究的重要基础。区分初级生产力与溶解作用的能力，同样对建立区域碳酸盐补偿深度（carbonate compensation depth, CCD）具有重要意义。本研究报道了东赤道太平洋综合大洋钻探计划（Integrated Ocean Drilling Program, IODP）U1335、U1337、U1338孔以及大洋钻探计划（Ocean Drilling Program, ODP）849孔的晚中新世以来的时间序列数据，包括X射线荧光光谱法（X-ray Fluorescence, XRF）测得的沉积物整体组成与质量堆积速率（mass accumulation rates, MAR）；同时还报道了ODP 848、850、851孔基于堆积密度得到的碳酸钙质量堆积速率数据。我们利用物理性质参数、XRF整体化学扫描数据、成像资料以及已有的年代地层学数据，对各钻孔的记录开展深度空间内的相互关联对比。随后我们应用一套新的东赤道太平洋年龄模型，为过去8百万年建立了分辨率为1~2千年（kyr）的关联年代记录。该时段内碳酸钙与生物二氧化硅（biogenic opal，生物蛋白石）的质量堆积速率发生了大幅变化，但黏土沉积量始终保持相对稳定，这表明粉尘输入的铁沉积仅对赤道生产力起到次要的反馈作用。由于黏土沉积量相对恒定，碳酸钙占比或生物二氧化硅占比与黏土占比的比值可用于表征生物源物质堆积速率的变化。我们划定了5.3百万年以来的5个上新世-更新世低碳酸钙占比（Plio-Pleistocene Low CaCO₃ %, PPLC）区间。其中2个区间主要因高生物二氧化硅埋藏量稀释了碳酸钙而形成（PPLC-2：1685~2135 ka，PPLC-5：4465~4737 ka），其余3个区间则因碳酸钙溶解作用增强所致（PPLC-1：51~402 ka，PPLC-3：2248~2684 ka，PPLC-4：2915~4093 ka）。碳酸钙占比最小值的区域分布模式，可以区分“高硅藻生物二氧化硅稀释作用导致的低碳酸钙含量”与“碳酸钙溶解增强导致的低碳酸钙含量”。通过扫描XRF测得的钡（Ba）元素数据，可以验证碳酸钙溶解作用的存在。[…]