A Miocene (Langhian–Tortonian, ca. 15–10 Ma) tropical ramp system exposed in southern Puerto Rico is characterized by shallow-water facies consisting of heterozoans, red algae, large benthic foraminifera (LBF), and corals, which occur as isolated corals, segment- and cluster-type reefs, and reworked accumulations. Photozoan association components are limited to corals (Montastraea, Porites, Goniopora, and Agaricia) and LBF (amphisteginids, soritids, gypsinids, miliolids) that have been documented to tolerate elevated nutrients, turbidity, and cooler water conditions. Similar shallow-water carbonate systems are found throughout the Caribbean, and this regional development is thought to have resulted from the well-documented upwelling in the Caribbean during the Miocene. Sea-level fluctuations also exerted a major control on facies distributions and shifts in the Puerto Rico ramp, including a vertical facies pattern that occurs in each of three sequences. Basal parts of sequences, deposited during sea-level rises, are dominantly composed of mollusks, echinoderms, red algae, LBF, bryozoans, and solitary corals that formed in low-energy seagrass-bed environments with local associated higher-energy shoal environments. Coral facies occur only in upper parts of sequences and formed in shallow-water, low- to high-energy environments closely associated with seagrass beds during late highstands and sea-level falls. A similar vertical facies pattern occurs in time-equivalent sequences elsewhere around the Caribbean. Strontium-isotope age data indicate two sequence boundaries reflecting sea-level falls formed at about 12.3 Ma and 11.1 Ma. Correlation with time-equivalent unconformities in other well-dated areas in the Caribbean and to sea-level lows on eustatic curves suggests a global signature for sequence development. The connection between the Caribbean and the Pacific along the Central American Seaway (CAS), impacted by local tectonic episodes and sea-level fluctuations during the Miocene, affected nutrient influx and upwelling in the Caribbean, which may be reflected in the vertical facies pattern in shallow-water carbonate sequences. Times of restricted connection during sea-level falls and lows resulted in reduced nutrients and upwelling, which may have been more conducive to coral development. Time-equivalent tropical carbonate systems in the Mediterranean and Indo-Pacific show similarities to those in the Caribbean, indicating influence of global processes (cooling, temperature gradients, oceanographic circulation). Differences between areas indicates the importance of local and regional controls, which in the Caribbean was dominantly the opening and closure of the CAS.

中文翻译：

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海平面和上升流对波多黎各庞塞中新世浅水热带碳酸盐斜坡系统发育的影响

中新世（Langhian-Tortonian，约 15-10 Ma）热带斜坡系统暴露在波多黎各南部珊瑚、分段和簇状珊瑚礁，以及重新加工的堆积物。Photozoan 关联成分仅限于珊瑚（Montastraea、Porites、Goniopora 和 Agaricia）和 LBF（amphisteginids、soritids、gypsinids、miliolids），它们已被证明可以耐受高营养、浊度和较冷的水条件。整个加勒比地区都发现了类似的浅水碳酸盐系统，这种区域发展被认为是中新世有充分记录的加勒比地区上升流的结果。海平面波动也对波多黎各斜坡的相分布和位移施加了主要控制，包括在三个序列中的每一个中出现的垂直相模式。在海平面上升期间沉积的层序的基础部分主要由软体动物、棘皮动物、红藻、LBF、苔藓动物和孤立的珊瑚组成，这些珊瑚形成于低能量海草床环境中，局部相关的高能量浅滩环境。珊瑚相仅出现在层序的上部，形成于浅水、低能到高能环境，与晚高位和海平面下降期间与海草床密切相关。类似的垂直相模式出现在加勒比地区其他地方的时间等效序列中。锶同位素年龄数据表明反映海平面下降的两个序列边界形成于大约 12 岁。3 毫安和 11.1 毫安。与加勒比地区其他年代久远的地区的时间等效不整合面以及浮海曲线上的海平面低点的相关性表明了序列发展的全球特征。加勒比与太平洋沿中美洲航道（CAS）的连接，受中新世局部构造事件和海平面波动的影响，影响了加勒比地区的营养物质流入和上升流，这可能反映在浅水碳酸盐层序。海平面下降和低点期间连接受限导致营养物质减少和上升流，这可能更有利于珊瑚的发育。地中海和印度洋-太平洋的时间等效热带碳酸盐系统与加勒比地区的相似，表明全球过程（冷却、温度梯度、海洋环流）的影响。地区之间的差异表明地方和区域控制的重要性，在加勒比地区，CAS 的开放和关闭占主导地位。