The closure of the Central American Seaway (CAS) resulted in changes of ocean‐climate dynamics since the late Miocene following the uplift of northern Andes. Reconstructing the bottom‐water temperatures (BWTs) of the Caribbean Sea illustrates feedbacks of the closure on the ocean‐climate system including deep‐water dynamics of the Caribbean Sea. Here, Mg/Ca‐derived BWTs of the Plio‐Pleistocene Caribbean Sea from the benthic foraminifer Cibicidoides wuellerstorfi are presented for the first time and interpreted along with Na/Ca and Sr/Ca as proxies of salinity and continental input, respectively. Our results highlight several warm (93, Gi15‐19, and N1) and cool (92, M2, Gi20, and CN4) marine isotope stages (MISs). Accordingly, changes in the circulation of deep‐water masses during the CAS closure developed in four main time intervals: (I) between 5.2 and 4.1 Ma (million years ago) BWT was ~1.1°C, (II) 4.1–3.2 Ma ~2.1°C, (III) 3.2–2.7 Ma ~2.7°C, and (IV) 2.7–2.2 Ma ~2.1°C. Relatively higher, gradually increased temperatures between 3.2 and 2.7 Ma correspond to late Pliocene warmth and restricted inflow of Pacific waters into the Caribbean due to shoaling of the CAS. In addition, Sr/Ca values reveal gradually escalating terrigenous input until 2.7 Ma most likely related to the increased river discharge in response to the Andean uplift. The gradual decrease of the BWTs from 2.7 Ma may have resulted from the onset of Northern Hemisphere Glaciation. Overall, BWTs match with previous sea surface temperatures from the planktic foraminifer Neogloboquadrina dutertrei. The BWTs presented here confirm intensified thermohaline circulation during the overall Pliocene warmth with increased bottom‐water Na/Ca values indicating enhanced salinity.

中文翻译：

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横跨中美洲海道封闭的深层热盐环流

自中新世晚期安第斯山脉北部隆升以来，中美洲海道（CAS）的关闭导致海洋气候变化。重建加勒比海的底水温度（BWT）说明了海洋气候系统关闭的反馈，包括加勒比海的深水动力学。在这里，来自底栖有孔虫Cibicidoides wuellerstorfi的上新世-加勒比海的Mg / Ca衍生的BWT首次出现，并与Na / Ca和Sr / Ca分别解释为盐度和大陆输入的代理。我们的结果突出显示了几个海洋同位素阶段（MISs）的几个暖（93，Gi15-19和N1）和冷（92，M2，Gi20和CN4）。因此，CAS封闭期间深水团的循环变化主要在四个时间间隔内发展：（I）5.2至4.1 Ma（百万年前）BWT为〜1.1°C，（II）4.1–3.2 Ma〜 2.1°C，（III）3.2–2.7 Ma〜2.7°C和（IV）2.7–2.2 Ma〜2.1°C。相对较高，逐渐升高的温度在3.2至2.7 Ma之间，这对应于上新世晚期的温暖，并且由于CAS的滩涂，太平洋水域流入加勒比海受到限制。此外，Sr / Ca值显示陆源输入逐渐升级，直到2。7 Ma最有可能与安第斯山脉抬升引起的河流流量增加有关。BWTs从2.7 Ma逐渐降低可能是由于北半球冰川的开始。总体而言，BWT与浮游有孔虫以前的海面温度相匹配Neogloboquadrina dutertrei。此处介绍的BWT证实了上新世整体变暖期间热盐环流的加剧，底水Na / Ca值增加表明盐度增加。