Abstract Long-term variations in eustatic sea level in an ice-free world, which existed through most of the Mesozoic and early Cenozoic eras, are partly driven by changes in the volume of ocean basins. Previous studies have determined ocean basin volume changes from plate tectonic reconstructions since the Mesozoic; however, these studies have not considered a number of important elements that contribute to ocean basin volume, such as regional differences in sedimentation, or uncertainties within the plate tectonic model itself, such as spreading asymmetries and the incomplete representation of back-arc basins in the Mesozoic. Additionally, studies on long-term changes in sea level related to the extension and rifting of passive margins have not been performed on a global-scale and likely significantly underestimated the influence of this process. In order to improve reconstructions of sea level on geologic time scales and assess the uncertainty in deriving the volume of ocean basins based on a global plate kinematic model, we investigate the influence of back-arc basins, spreading asymmetry, large igneous provinces (LIPs), sediment thickness, and passive margins on ocean basin volume since 200 Ma. We find that less-constrained plate tectonic elements, such as the presence of back-arc basins or spreading asymmetry, may contribute up to ~120 m or ~150 m to sea level respectively. Changes in the sea level related to sedimentation and LIPs are respectively ~75–165 m and ~45 m. Changes in sea level associated with passive margin formation are almost negligible at present day, though were much larger in the Cretaceous, and the assumed sedimentation style strongly influences the rate and magnitude of sea-level change. We incorporate predictions for these components during times where ocean basins are predominantly synthetic reconstructions and find that sea level driven by fluctuating ocean basin volume has changed by ~200 m since the Jurassic, which is comparable to previous estimates. Our revised estimates will need to be combined with other processes driving long-term sea-level change, including mantle convection-driven dynamic topography and glacio-eustasy for constructing a complete eustatic sea-level curve. Understanding and quantifying the uncertainties in the volume of ocean basins has implications for modelling subduction flux, the oceanic carbon cycle, and heatflow, and is important for exploring Earth's evolutionary cycles, especially during times in the geologic past where much of the ocean basin history has been lost.

中文翻译：

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超大陆分裂后全球海盆体积变化引起的海平面波动

摘要 在中生代和新生代早期的大部分时期都存在的无冰世界中海平面的长期变化部分是由洋盆体积的变化驱动的。先前的研究已经确定了自中生代以来板块构造重建的洋盆体积变化；然而，这些研究并未考虑影响海盆体积的一些重要因素，例如沉积的区域差异，或板块构造模型本身的不确定性，例如不对称扩展和弧后盆地在海洋中的不完整表示。中生代。此外，尚未在全球范围内对与被动边缘的伸展和裂谷相关的海平面长期变化进行研究，并且可能大大低估了这一过程的影响。为了改进地质时间尺度上的海平面重建，并评估基于全球板块运动学模型推导出海盆体积的不确定性，我们调查了弧后海盆、扩展不对称性、大型火成岩省 (LIP) 的影响、沉积厚度和自 200 Ma 以来海盆体积的被动边缘。我们发现约束较少的板块构造元素，例如弧后盆地的存在或不对称扩展，可能对海平面的影响分别高达 ~120 m 或 ~150 m。与沉积和 LIP 相关的海平面变化分别为~75-165 m 和~45 m。目前与被动边缘形成相关的海平面变化几乎可以忽略不计，尽管在白垩纪要大得多，假设的沉积方式强烈影响海平面变化的速度和幅度。我们在海盆主要是合成重建的时期对这些组件进行了预测，并发现自侏罗纪以来，由波动的海盆体积驱动的海平面变化了约 200 m，这与之前的估计值相当。我们修正后的估计需要与驱动长期海平面变化的其他过程相结合，包括地幔对流驱动的动态地形和冰川-eustasy，以构建完整的海平面曲线。理解和量化海洋盆地体积的不确定性对模拟俯冲通量、海洋碳循环和热流具有重要意义，对于探索地球的演化循环也很重要，