Our understanding of the long‐term evolution of the Earth system is based on the assumption that terrestrial weathering rates should respond to, and hence help regulate, atmospheric CO₂ and climate. Increased terrestrial weathering requires increased carbonate accumulation in marine sediments, which in turn is expected to result in a long‐term deepening of the carbonate compensation depth (CCD). Here, we critically assess this long‐term relationship between climate and carbon cycling. We generate a record of marine deep‐sea carbonate abundance from selected late Paleocene through early Eocene time slices to reconstruct the position of the CCD. Although our data set allows for a modest CCD deepening, we find no statistically significant change in the CCD despite >3 °C global warming, highlighting the need for additional deep‐sea constraints on carbonate accumulation. Using an Earth system model, we show that the impact of warming and increased weathering on the CCD can be obscured by the opposing influences of ocean circulation patterns and sedimentary respiration of organic matter. From our data synthesis and modeling, we suggest that observations of warming, declining δ¹³C and a relatively stable CCD can be broadly reproduced by mid‐Paleogene increases in volcanic CO₂ outgassing and weathering. However, remaining data‐model discrepancies hint at missing processes in our model, most likely involving the preservation and burial of organic carbon. Our finding of a decoupling between the CCD and global marine carbonate burial rates means that considerable care is needed in attempting to use the CCD to directly gauge global carbonate burial rates and hence weathering rates.

中文翻译：

---

早期新生代气候与碳酸盐补偿深度趋势的脱钩。

我们对地球系统长期演化的理解是基于这样的假设：陆地风化率应该对大气 CO 2 和气候做出反应，从而帮助_调节。陆地风化作用的增加需要海洋沉积物中碳酸盐积累的增加，这反过来预计将导致碳酸盐补偿深度（CCD）的长期加深。在这里，我们批判性地评估了气候与碳循环之间的长期关系。我们生成了从选定的晚古新世到早始新世时间切片的海洋深海碳酸盐丰度记录，以重建 CCD 的位置。尽管我们的数据集允许适度的 CCD 加深，但尽管全球变暖超过 3°C，但我们发现 CCD 没有统计上显着的变化，这突出表明需要对碳酸盐积累进行额外的深海限制。使用地球系统模型，我们表明变暖和风化加剧对 CCD 的影响可能会被海洋环流模式和有机物沉积呼吸的相反影响所掩盖。根据我们的数据合成和建模，我们认为对变暖、δ ¹³ C 下降和相对稳定的 CCD 的观测可以通过古近纪中期火山 CO ₂释气和风化的增加来广泛再现。然而，剩余的数据模型差异暗示我们的模型中缺少过程，最有可能涉及有机碳的保存和埋藏。我们发现 CCD 与全球海洋碳酸盐埋藏率之间存在脱钩，这意味着在尝试使用 CCD 直接测量全球碳酸盐埋藏率以及风化率时需要相当小心。