The deep-sea stratigraphic record is full of gaps. These hiatuses track changes in ocean circulation and chemistry, but determining their timing and causes has been limited by sparse data and incomplete knowledge of ocean gateway evolution in earlier studies. We combine a significantly expanded, age-calibrated deep-sea stratigraphic database with a global tectonic and paleo–water depth model to investigate the distribution of >400 Cenozoic hiatuses longer than ~0.2 m.y. We find that only a small number of hiatuses are due to carbonate dissolution. The majority of hiatuses were, by implication, caused by mechanical erosion and redistribution of sediments by bottom currents into regions of increased sedimentation such as contourite drifts. We link peaks in regional hiatuses to changes in ocean circulation and intensification of deep-water formation. Widespread hiatuses in the South Atlantic, South Pacific, and southern Indian oceans between ca. 34 Ma and 30 Ma are attributed to the coeval widening and deepening of the Drake Passage and the opening of the deep Tasman Gateway. A peak in hiatuses in the Atlantic in the early Miocene is linked to the initiation of a proto–Atlantic Meridional Overturning Circulation driven by the complete opening of the deep Drake Passage and the progressive closure of the Tethys seaway. A long-term 30% decline in hiatus frequency since ca. 14 Ma is synchronous with post–Miocene Climate Optimum cooling, suggesting the slowing of abyssal circulation. Our synthesis of deep-sea hiatuses could be used to track the fate of deep-sea sediments and to ground-truth deep-ocean circulation models.The deep-sea stratigraphic record is pervaded by hiatuses (Keller and Barron, 1983; Keller et al., 1987). These discontinuities are chiefly caused by mechanical erosion of the seafloor by currents, dissolution of biogenic carbonate associated with fluctuations of the carbonate compensation depth (CCD), or periods of nondeposition (Keller and Barron, 1983; Moore et al., 1978). Based on the stratigraphy of Deep-Sea Drilling Project (DSDP) sites, a number of pioneering investigations in the 1980s suggested that deep-sea hiatuses are largely the result of major changes in ocean circulation and the flow of bottom currents and may be linked to climatic perturbations (Keller and Barron, 1983; Keller et al., 1987). But these ground-breaking interpretations were made using relatively sparse data without consideration of the fate of the missing material and without a global tectonic model, leading to misidentification of key events. We assess the distribution of deep-sea hiatuses and their paleo–water depths based on nearly 300 deep-sea drill holes using a plate-tectonic model that includes stretching along rifted margins. We couple this analysis with a global data set of contourite drifts (Thran et al., 2018) with maximum age constraints to connect hiatus formation to potential regions of excess deposition. We use a set of regional CCD reconstructions to consider the role of carbonate dissolution in forming hiatuses. Our analysis gives new insights into the link between seafloor sediment redistribution, gateway evolution, and the vigor of ocean-bottom currents.We have selected age-depth models for 293 deep-sea drill holes (Fig. 1; Table S1 in the Supplemental Material1) from the Neptune Sandbox Berlin (NSB) database (http://www.nsb-mfn-berlin.de/), which is based on harmonized, updated, and accurate lists of microfossils (Renaudie et al., 2020). The age models have been calibrated to the Gradstein et al. (2012) time scale. We follow Spencer-Cervato (1998) in defining hiatuses as gaps in the stratigraphic record longer than 0.18 m.y. and in assuming that they are accurately represented in the biostratigraphic NSB data. The quality of the age models used is discussed in Renaudie et al. (2020). We disregard sites where the age-depth relationship is very poorly constrained. The number of sites increases steadily from a low of 48 at 66 Ma to a high of 207 at 2.5 Ma (Fig. 2A), yielding a total of 409 hiatuses over the Cenozoic. Our global data set across all ocean basins, including on submerged continental crust, and in variable water depths minimizes bias introduced by drilling objectives and drilling methods. This is partially expressed in the lack of bias in hiatus duration for our entire time series (Fig. S1). Additionally, Spencer-Cervato (1998) concluded that incomplete core recovery, typical at DSDP sites, did not result in false hiatuses. DSDP and Ocean Drilling Program (ODP) holes from comparable water depths, e.g., on the Walvis Ridge, have similar resolution and show good agreement in age-depth models (e.g., DSDP Site 524 versus ODP Site 1267, and DSDP Site 525 versus Site ODP 1264) (see Table S1, and data files in the Supplemental Material1), although direct comparison is difficult because location and water depth of the holes is not the same. The time of hiatus onset is imprecise because the amount of sediment removed is unknown (Moore et al., 1978), also limiting mass-balance considerations between areas of erosion and deposition. Thus, the age of hiatus initiation is based on the age of underlying sediment and represents a maximum, while the age of hiatus cessation is determined by the age of overlying sediment. We construct paleobathymetry grids for oceanic and stretched continental crust including a correction for dynamic topography model “M7” (Müller et al., 2018a) using pyBacktrack version 1.4 (Müller et al., 2018b) and extract paleo–water depths for each drill site.The frequency of deep-sea hiatus occurrence has fluctuated throughout the Cenozoic (Fig. 2A; Video S1), driven by regional as well as larger-scale changes in ocean circulation and sediment redistribution. The vast majority of hiatuses (72%) are <5 m.y. in duration, 23% of hiatuses are between 5 and 20 m.y. long, and 5% of hiatuses are longer than 20 m.y. (Fig. 2B). The paleo–water depth at which the hiatuses formed show a trimodal distribution—shallow (<2000 m), intermediate (2000–3000 m), and deep (>3500 m) (Fig. 2C). While shallow and intermediate hiatuses fluctuate in frequency throughout the Cenozoic, deep hiatuses show a marked increase only during the mid- to late Miocene (Fig. 2A). Only a small number of deep hiatuses occur below the CCD during the Eocene and the mid- to late Miocene, when the CCD was at its shallowest at ~3000–3500 m (Fig. 2D). This suggests that most hiatuses longer than ~0.2 m.y. are the result of mechanical erosion and transfer of sediments by currents.In order to investigate the complex history of hiatus occurrence, we focus on hiatus frequency as a function of paleo–water depths (Fig. 2C) in five ocean basins with sufficient data coverage (Fig. 3) spanning times of major oceanographic change. Sites in the Southern Ocean have been assigned to the South Atlantic, the South Pacific, or the Indian Ocean due to paucity of data in that region. We reconstruct the location of hiatuses and non-hiatuses in a paleobathymetric context (Video S1), highlighting hiatuses that likely formed due to carbonate dissolution below the CCD (Fig. 4).In the Paleocene, most of the hiatuses occur on topographic highs in all ocean basins (Fig. 4A) at depths above the regional CCD (Fig. 3), which is unlikely to have been shallower than 3 km (Fig. 2D). These hiatuses are significantly longer (>>1 m.y.) than the relatively brief late Paleocene carbonate dissolution event that has been linked to changes in Pacific Ocean circulation (Hancock and Dickens, 2006). The Paleocene was warm (Fig. 3A; Westerhold et al., 2020), with deep water forming in the North Atlantic and Southern Ocean (Corfield and Norris, 1996) and the South and North Pacific (Thomas et al., 2008). The thermohaline circulation driven by these sites of deep-water formation most likely caused the long-lived hiatuses we observe at this time, especially at sites located on marginal and oceanic plateaus acting as obstacles to deep-water flow and hence susceptible to sustained erosion by currents. Sparse data for this period preclude an assessment of potential sites of deposition associated with the hiatuses. However, topographic features such as seamounts and plateaus are known to impinge as well as enhance current speeds (Rebesco et al., 2014), which is supported by the regional co-occurrence of hiatuses and conformities throughout the ocean basins (Fig. 3).A hiatus peak in the South Atlantic in the mid- to late Eocene (ca. 43–39 Ma) (Fig. 3C) is marked by the appearance of hiatuses at intermediate paleo–water depths around the Rio Grande Rise–Walvis Ridge region (Fig. 4B; Video S1). The CCD in the central South Atlantic was substantially shallower (at ~3.5 km) than in the rest of the Atlantic at 43 Ma (Fig. 2D), suggesting that the Rio Grande Rise–Walvis Ridge hiatuses were most likely caused by carbonate dissolution, possibly shifting carbonate deposition to regions of deeper CCD in the ocean basin. However, it is impossible to establish a carbonate mass balance from the marine sedimentary record and CCD fluctuations alone because carbonate abundance cannot be used to uniquely infer causal mechanisms of deep- to shallow-marine carbonate fractionation (Boss and Wilkinson, 1991).Widespread hiatuses occur in the South Atlantic at depths of 2000–3500 m and in the South Pacific and southern Indian Ocean at depths of <2000 m (Figs. 3C, 3E, 3F, and 4C) between ca. 34 Ma and 30 Ma. This hiatus peak is accompanied by the appearance of giant contourite drifts in the South Atlantic (Fig. 4C; Video S1) such as those along the Argentine continental margin (Hernández-Molina et al., 2010). The Eocene-Oligocene transition at ca. 34 Ma marks a dramatic shift from a Warmhouse to a Coolhouse climate (Fig. 3A; Westerhold et al., 2020) and a deepening of the CCD in all ocean basins, notably in the North Pacific (Fig. 2D) where hiatuses are relatively uncommon at this time. Most of the Oligocene hiatuses are likely the result of major changes in ocean circulation triggered by the combined widening and deepening of the Drake Passage (Eagles and Jokat, 2014) and the opening of the deep Tasman Gateway connecting the South Pacific and Indian Ocean at ca. 33.5 Ma (Scher et al., 2015). In a recent ice-sheet climate simulation, the opening of these gateways together with the onset of Antarctic glaciation results in increased atmospheric pressure gradients and westerly winds ~60°S, cooling surface waters, and intensifying Antarctic deep-water formation (Kennedy-Asser et al., 2019). Together, these modeled changes predict the onset of the modern Antarctic Circumpolar Current (ACC) at ca. 30 Ma, supporting a previous inference by Scher et al. (2015) based on the Southern Ocean neodymium isotope record. The enhanced overturning circulation was most pronounced in the Southern Hemisphere, as reflected in our observed increase in the frequency of South Atlantic, Indian, and South Pacific ocean hiatuses (Figs. 3C, 3E, and 3F) and the appearance of widespread contourite drifts in the South Atlantic (Hernández-Molina et al., 2010).The beginning of the Miocene is marked by an increase of hiatuses at intermediate water depths in the South Atlantic (Fig. 3C) and at intermediate and shallow depths in the North Atlantic (Fig. 3B). These are accompanied by the initiation of contourites in the Norwegian-Greenland Sea, the equatorial Atlantic, and the Scotia Sea (Fig. 4D; Video S1), representing nearby sites of deposition of eroded material. We interpret this event as the initiation of a proto–Atlantic Meridional Overturning Circulation (AMOC) driven by the complete opening of the deep Drake Passage at ca. 23 Ma (Eagles and Jokat, 2014) and the progressive closure of the Tethys seaway at 20 Ma (Bialik et al., 2019), which has been shown to enhance the ACC and proto-AMOC (Hamon et al., 2013) based on ocean models. In addition, the early Miocene deepening of the Fram Strait and the Greenland-Scotland Ridge connected the Arctic to the northeastern Atlantic as another critical element for developing the AMOC (Straume et al., 2020). This corresponds to the appearance of new hiatuses and contourite drifts (Video S1) in the Norwegian-Greenland Sea, such as the Eirik Drift (Fig. 4D), which was initiated around this time by Northern Component Water (Müller-Michaelis et al., 2013). A reduction in the frequency of hiatuses in the North Atlantic (Fig. 3B) coincides with the plume-driven uplift of the Greenland-Scotland Ridge between 18 Ma and 15 Ma (Straume et al., 2020) causing a weakening of North Atlantic deep-water formation. The Greenland-Scotland Ridge starts subsiding again after 15 Ma while the Fram Strait becomes fully open (Straume et al., 2020), reinvigorating AMOC and increasing the frequency of hiatuses throughout the Atlantic (Figs. 3B and 3C).Hiatus peaks since ca. 13 Ma display a distinct decreasing global trend in frequencies from 35% to ~10% in the Quaternary (Fig. 2A), tracking post–Miocene Climate Optimum global cooling (Fig. 3A). A similar decreasing trend was noted by Spencer-Cervato (1998) but only for the last 5 m.y. and which remained unexplained in terms of paleoceanographic changes. A small decrease in hiatuses may be explained by a 1 km deepening of the CCD since the late Miocene, reducing the maximum number of deep-water hiatuses such as those in the South Atlantic caused by carbonate dissolution at 13 Ma (Figs. 2D and 4E). However, the vast majority of hiatuses already occurred above the CCD before this deepening (Fig. 2D) and only increase slightly during the Miocene carbonate crash (Fig. 2D). We suggest that the decline in hiatus frequency is more likely due to a slowing of abyssal circulation since the mid-Miocene and a reduction in interoceanic deep-water flow rates as indicated by a range of proxy records including magnetic fabric analysis of contourite drifts (Hassold et al., 2009), effectively slowing bottom-current speeds and seafloor erosion. These observations are supported by ocean circulation models which suggest that deep-ocean ventilation is more vigorous in warm than in cold climates (de Boer et al., 2007). The dependence of density on temperature relative to salinity is increased at higher temperatures, reducing stratification upon warming by diminishing polar freshwater stabilization, contributing to increased convection and deep-water formation (de Boer et al., 2007). A second key process in driving the speed of the deep global ocean circulation is the intensity of surface winds, which was found to have increased with global warming over the past two decades, but this effect is difficult to validate in deep time (Hu et al., 2020). The late Miocene to recent trend of decreasing hiatus frequency we observe provides a missing observational link, given that a waning vigor of intermediate and deep circulation during global cooling would result in decreasing hiatus occurrence.Our analysis of Cenozoic deep-sea hiatuses in a tectonic and paleobathymetric framework illustrates that the hiatus record can be used as a proxy for the vigor of deep-ocean circulation and for tracking paleoceanographic effects of the opening of key gateways. Our synthesis of deep-sea hiatuses could be used for tracking the fate of deep-sea sediments and for ground-truthing deep-ocean circulation models.This manuscript benefitted hugely from reviews by Mitchell Lyle, Philip Sexton, Ted Moore, and Editor Gerald Dickens. We thank John Cannon and Xiaodong Qin for technical support. This research was supported by the Australian Research Council Future Fellowship grant FT190100829 to A.D. and by AuScope. All figures were made using Generic Mapping Tools (GMT) version 6.1.

中文翻译：

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深海裂隙追踪新生代海底洋流的活力

深海地层记录充满了空白。这些中断跟踪海洋环流和化学的变化，但确定它们的时间和原因受到早期研究中数据稀少和海洋网关演化知识不完整的限制。我们将显着扩展的、经过年龄校准的深海地层数据库与全球构造和古水深模型相结合，以研究 > 400 个新生代裂隙的分布，长度超过 ~0.2 米 我们发现只有少数裂隙是由于碳酸盐溶解。大多数中断是由机械侵蚀和底流将沉积物重新分配到沉积物增加的区域（例如等高线漂移）引起的。我们将区域中断的峰值与海洋环流的变化和深水形成的强化联系起来。南大西洋、南太平洋和南印度洋之间的广泛中断。34 Ma 和 30 Ma 归因于同时代德雷克海峡的拓宽和加深以及深塔斯曼门户的开放。中新世早期大西洋中断的高峰与由德雷克深水道完全开放和特提斯海道逐渐关闭驱动的原始大西洋经向翻转环流的开始有关。自 ca 以来，中断频率长期下降 30%。14 Ma 与中新世后气候最适降温同步，表明深海环流放缓。我们对深海裂隙的合成可用于追踪深海沉积物的命运和建立真实的深海环流模型。深海地层记录中遍布裂隙（Keller 和 Barron，1983；Keller 等人） ., 1987)。这些不连续性主要是由洋流对海底的机械侵蚀、与碳酸盐补偿深度 (CCD) 波动相关的生物碳酸盐溶解或非沉积期造成的 (Keller 和 Barron, 1983; Moore 等人, 1978)。基于深海钻探项目 (DSDP) 场地的地层学，1980 年代的一些开创性调查表明，深海中断主要是海洋环流和底流流动发生重大变化的结果，可能与气候扰动（Keller 和 Barron，1983；Keller 等，1987）。但是这些突破性的解释是使用相对稀疏的数据进行的，没有考虑丢失材料的命运，也没有全球构造模型，导致对关键事件的错误识别。我们使用包括沿裂谷边缘伸展的板块构造模型，基于近 300 个深海钻孔评估了深海裂隙的分布及其古水深度。我们将此分析与轮廓漂移的全球数据集（Thran 等人，2018 年）相结合，具有最大年龄限制，以将裂孔形成与过度沉积的潜在区域联系起来。我们使用一组区域 CCD 重建来考虑碳酸盐溶解在形成裂隙中的作用。我们的分析为海底沉积物再分布、网关演化、和海底洋流的活力。我们从海王星沙盒柏林（NSB）数据库（http://www .nsb-mfn-berlin.de/)，它基于协调、更新和准确的微化石列表（Renaudie 等人，2020 年）。年龄模型已根据 Gradstein 等人进行了校准。（2012）时间尺度。我们遵循 Spencer-Cervato (1998) 将中断定义为地层记录中长于 0.18 米的间隙，并假设它们在生物地层 NSB 数据中得到准确表示。Renaudie 等人讨论了所用年龄模型的质量。（2020 年）。我们忽略年龄-深度关系约束非常差的站点。站点数量从 66 Ma 时的 48 个低点稳步增加到 2 个时的 207 个。5 Ma（图 2A），在新生代上总共产生了 409 个裂口。我们在所有海洋盆地（包括水下大陆地壳）和不同水深的全球数据集最大限度地减少了钻井目标和钻井方法引入的偏差。这部分表现在我们整个时间序列的中断持续时间没有偏差（图S1）。此外，Spencer-Cervato (1998) 得出结论，在 DSDP 站点典型的不完全堆芯恢复不会导致错误的中断。来自可比水深的 DSDP 和海洋钻探计划 (ODP) 钻孔，例如，在沃尔维斯海脊，具有相似的分辨率，并且在年龄深度模型中显示出良好的一致性（例如，DSDP Site 524 与 ODP Site 1267，以及 DSDP Site 525 与 Site ODP 1264）（见表 S1，以及补充材料 1 中的数据文件），虽然直接比较很困难，因为孔的位置和水深不一样。中断开始的时间是不精确的，因为去除的沉积物数量是未知的（Moore 等，1978），这也限制了侵蚀和沉积区域之间的质量平衡考虑。因此，中断开始的年龄基于下伏沉积物的年龄并代表最大值，而中断停止的年龄由上覆沉积物的年龄确定。我们使用 pyBacktrack 版本 1.4（Müller 等人，2018b）为海洋和伸展的大陆地壳构建古水深测量网格，包括对动态地形模型“M7”（Müller 等人，2018a）的校正，并提取每个钻探地点的古水深. 深海裂隙发生的频率在整个新生代都有波动（图 2A；视频 S1），受海洋环流和沉积物重新分布的区域性和更大规模变化的驱动。绝大多数中断（72%）的持续时间小于 5 米，23% 的中断在 5 到 20 米之间，5% 的中断超过 20 米（图 2B）。裂隙形成的古水深呈现出浅层（<2000 m）、中层（2000~3000 m）和深层（>3500 m）三峰分布（图2C）。虽然在整个新生代中浅层和中层裂隙的频率波动，但深裂隙仅在中新世中晚期显示出显着增加（图 2A）。在始新世和中新世中晚期，CCD下方仅出现少量深裂隙，此时CCD在~3000-3500 m处最浅（图2D）。这表明大多数中断时间超过 ~0.2 my 是机械侵蚀和水流转移沉积物的结果。为了研究中断发生的复杂历史，我们将重点放在具有足够数据覆盖的五个海洋盆地中作为古水深的函数的中断频率（图2C） （图3）主要海洋变化的跨越时间。由于该地区缺乏数据，南大洋的站点已被分配到南大西洋、南太平洋或印度洋。我们在古水深测量的背景下重建了裂隙和非裂隙的位置（视频 S1），突出了可能由于 CCD 下方的碳酸盐溶解而形成的裂隙（图 4）。在古新世，大部分裂隙发生在所有海洋盆地（图 4A）都在区域 CCD （图 3）以上的深度，这不太可能比 3 公里浅（图 3）。2D）。与太平洋环流变化相关的相对短暂的晚古新世碳酸盐溶解事件相比，这些中断明显更长（>1 米）（Hancock 和 Dickens，2006）。古新世温暖（图 3A；Westerhold 等，2020），在北大西洋和南大洋（Corfield 和 Norris，1996）以及南太平洋和北太平洋（Thomas 等，2008）形成深水。由这些深水形成地点驱动的温盐环流最有可能导致我们此时观察到的长期中断，特别是在边缘和海洋高原的地点，这些地点成为深水流动的障碍，因此容易受到持续侵蚀电流。这一时期的稀疏数据排除了对与中断相关的潜在沉积地点的评估。然而，众所周知，海山和高原等地形特征会影响并提高当前速度（Rebesco 等人，2014 年），这一点得到了整个海洋盆地中裂隙和整合的区域性同时出现的支持（图 3）。始新世中晚期（约 43-39 Ma）（图 3C）的南大西洋裂隙峰的标志是在格兰德河隆起-沃尔维斯海岭地区周围的中间古水深出现裂隙（图 3C）。 . 4B；视频 S1)。在 43 Ma 时，南大西洋中部的 CCD 比大西洋其他地区的 CCD 浅得多（约 3.5 公里）（图 2D），这表明里奥格兰德隆起 - 沃尔维斯海脊裂隙很可能是由碳酸盐溶解引起的，可能将碳酸盐沉积转移到海洋盆地中更深的 CCD 区域。然而，仅从海洋沉积记录和 CCD 波动中建立碳酸盐物质平衡是不可能的，因为碳酸盐丰度不能用于唯一推断深海到浅海碳酸盐分馏的因果机制（Boss 和 Wilkinson，1991）。 2000-3500 米深度的南大西洋和 2000 米以下深度的南太平洋和南印度洋（图 3C、3E、3F 和 4C）约 200 米（图 3C、3E、3F 和 4C）34 毫安和 30 毫安。这一中断峰伴随着南大西洋巨大等高线漂移的出现（图 4C；视频 S1），例如沿着阿根廷大陆边缘的那些（Hernández-Molina 等，2010）。约始新世-渐新世过渡。34 Ma 标志着从暖屋气候到冷屋气候的巨大转变（图 3A；Westerhold 等人，2020）和所有海洋盆地的CCD加深，特别是在北太平洋（图2D），此时中断相对不常见。大多数渐新世中断可能是由于德雷克海峡（Eagles 和 Jokat，2014 年）的扩大和加深以及连接南太平洋和印度洋的塔斯曼深海门户在 ca . 33.5 Ma（Scher 等人，2015 年）。在最近的一次冰盖气候模拟中，这些通道的打开以及南极冰川作用的开始导致大气压力梯度增加和约 60°S 的西风，冷却地表水和加强南极深水形成（Kennedy-Asser等人，2019）。一起，这些模拟的变化预测了现代南极绕极流（ACC）的开始时间。30 Ma，支持 Scher 等人先前的推论。(2015) 基于南大洋钕同位素记录。增强的倾覆环流在南半球最为明显，这反映在我们观察到的南大西洋、印度洋和南太平洋中断频率的增加（图 3C、3E 和 3F）以及广泛的等高线漂移的出现。南大西洋 (Hernández-Molina et al., 2010)。图 3B)。这些伴随着挪威-格陵兰海、赤道大西洋等高线的形成，和斯科舍海（图 4D；视频 S1），代表附近的侵蚀物质沉积地点。我们将此事件解释为原始大西洋经向翻转环流（AMOC）的开始，这是由大约在大约 10 年的德雷克深水道完全开放所驱动的。23 Ma (Eagles and Jokat, 2014) 和 Tethys 航道在 20 Ma (Bialik et al., 2019) 逐渐关闭，这已被证明可以增强 ACC 和 proto-AMOC (Hamon et al., 2013)在海洋模型上。此外，弗拉姆海峡和格陵兰-苏格兰海脊的早期中新世加深将北极与大西洋东北部连接起来，成为发展 AMOC 的另一个关键因素（Straume 等，2020）。这对应于挪威-格陵兰海出现新的裂隙和等高线漂移（视频 S1），例如 Eirik 漂移（图 4D），这是由 Northern Component Water 发起的（Müller-Michaelis 等人，2013 年）。北大西洋中断频率的减少（图 3B）恰逢格陵兰-苏格兰海脊在 18 Ma 和 15 Ma 之间由羽流驱动的隆起（Straume 等人，2020），导致北大西洋深部减弱-水的形成。格陵兰-苏格兰海脊在 15 Ma 后再次开始下沉，而弗拉姆海峡完全开放（Straume 等人，2020 年），重振 AMOC 并增加整个大西洋的中断频率（图 3B 和 3C）。 . 13 Ma 显示第四纪频率从 35% 到 ~10% 的明显下降趋势（图 2A），跟踪中新世后气候最佳全球冷却（图 3A）。Spencer-Cervato (1998) 注意到了类似的下降趋势，但仅在过去 5 年中出现，并且在古海洋学变化方面仍未得到解释。自晚中新世以来 CCD 加深了 1 km 可以解释裂隙的小幅减少，减少了深水裂隙的最大数量，例如由 13 Ma 碳酸盐溶解引起的南大西洋深水裂隙（图 2D 和 4E） ）。然而，在加深之前，绝大多数裂隙已经发生在 CCD 上方（图 2D），并且在中新世碳酸盐崩塌期间仅略有增加（图 2D）。我们认为，中断频率的下降更可能是由于自中新世中期以来深海环流的减慢以及海洋间深水流速的减少，如一系列代理记录所表明的，包括等高线漂移的磁性织物分析（Hassold et al., 2009)，有效减缓了底流速度和海底侵蚀。这些观测得到了海洋环流模型的支持，这表明深海通风在温暖气候下比在寒冷气候下更加活跃（de Boer 等，2007）。在较高温度下，密度对温度相对于盐度的依赖性会增加，通过降低极地淡水稳定性来减少变暖时的分层，从而促进对流和深水形成（de Boer 等，2007）。推动全球深海环流速度的第二个关键过程是地表风的强度，在过去的 20 年中发现随着全球变暖而增加，但这种影响很难在深海时间验证（Hu et al ., 2020)。我们观察到的中新世晚期到最近的中断频率降低趋势提供了一个缺失的观测环节，因为全球降温期间中层和深层循环的活力减弱将导致中断发生率减少。我们对构造和构造中新生代深海中断的分析古水深测量框架表明，中断记录可以用作深海环流活力的代表，并用于跟踪关键通道开放的古海洋学影响。我们对深海裂隙的合成可用于追踪深海沉积物的命运和真实的深海环流模型。这份手稿从 Mitchell Lyle、Philip Sexton、Ted Moore 和编辑 Gerald Dickens 的评论中受益匪浅. 我们感谢 John Cannon 和 Xiaodong Qin 的技术支持。这项研究得到了澳大利亚研究委员会未来奖学金授予 AD 的 FT190100829 和 AuScope 的支持。所有数字均使用通用映射工具 (GMT) 6.1 版制作。这项研究得到了澳大利亚研究委员会未来奖学金授予 AD 的 FT190100829 和 AuScope 的支持。所有数字均使用通用映射工具 (GMT) 6.1 版制作。这项研究得到了澳大利亚研究委员会未来奖学金授予 AD 的 FT190100829 和 AuScope 的支持。所有数字均使用通用映射工具 (GMT) 6.1 版制作。