近日，美国迈阿密大学Sam J. Purkis团队研究了大巴哈马滩的沉积物收支——地球上最大的现代碳酸盐台地。相关论文发表在2025年6月23日出版的《地质学》杂志上。

结合遥感、现场采样和地震数据，研究组广泛量化了大巴哈马银行（GBB）的沉积物收支。这个孤立的碳酸盐台地在现代世界是独一无二的，因为它的巨大规模和丰富的非骨骼沉积物，使其成为地质历史上巨型台地的类比。尽管之前的研究侧重于预算的单一方面，如泥沙生产、出口或积累，但研究组调和了这三个方面。他们认为，GBB每年产生0.93−7.81×10¹³克沉积物，输出0.74−8.79×10¹³ g，累计2.24−57.31×10¹³ g。

岩心和地震数据证实，自6.7千年前洪水以来，GBB一直在追踪海平面上升，这至少需要一个平衡的预算。为了达到这样的效果，研究组认为GBB顶部的沉积物生产者必须已经达到或接近其最大的现代产能。因此，该研究挑战了非礁平台严重过度生产沉积物的观点。全新世GBB的预算显然比以前想象的更不稳定，如果受到气候变化的阻碍，可能无法追踪未来的海平面上升。

附：英文原文

Title: The sediment budget of Great Bahama Bank—Earth’s largest modern carbonate platform

Author: Cecilia Lopez-Gamundi, Brian B. Barnes, Christian Betzler, Paul M. Harris, Amanda M. Oehlert, Gregor P. Eberli, Sam J. Purkis

Issue&Volume: 2025-06-23

Abstract: Melding remote sensing, field sampling, and seismic data, we broadly quantify the sediment budget of Great Bahama Bank (GBB). This isolated carbonate platform is unique in the modern world because of its immense size and its abundance of non-skeletal sediments, making it an analog for the giant platforms of the geologic past. Whereas previous studies focused on singular aspects of the budget, such as sediment production, export, or accumulation, we reconcile all three. We contend that annually, GBB produces 0.937.81 × 1013 g of sediment, exports 0.748.79 × 1013 g, and accumulates 2.2457.31 × 1013 g. Cores and seismic data confirm that GBB has tracked rising sea level since flooding 6.7 k.y. ago, necessitating, at minimum and on average, a balanced budget. To perform as such, we contend that the sediment producers atop GBB must have produced at, or near, their maximum modern-day capacity. Our study therefore challenges the notion that non-reefal platforms grossly overproduce sediment. The budget of the Holocene GBB is apparently more precariously balanced than previously thought and may conceivably fail to track future sea-level rise if impeded by changing climate.

DOI: 10.1130/G52850.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52850.1/659182/The-sediment-budget-of-Great-Bahama-Bank-Earth-s