碳酸盐工厂通过 MECO（中始新世气候最佳）事件做出响应：来自意大利加尔加诺岬普利亚碳酸盐平台的见解,Sedimentary Geology

在始新世期间，浅水碳酸盐系统受到气候波动和高温事件的显着影响。在始新世早期气候最佳期 (EECO) 的峰值温度之后，总体变冷趋势开始，同时出现短暂的（⁓200 kyr）变暖事件。在巴顿纪早期（约40.1Ma），发生了被称为中始新世气候最适期（MECO）的变暖事件，持续约50万年。在这种情况下，珊瑚和较大的底栖有孔虫（LBF）等海洋生物的类型和钙化率受到全球CO 2和海洋变化的影响，这对光碳酸盐工厂产生了重大影响。为了更好地了解这些因素对碳酸盐工厂的影响，对浅水相类型、分布和演化进行了详细的研究。选择位于普利亚碳酸盐台地东缘（意大利南部加尔加诺岬）的中始新世萨拉切诺山序列作为案例研究，研究碳酸盐工厂类型与MECO事件周围气候变化之间的关系。这项研究确定了两个具有不同碳酸盐生产模式的不同层段，由清晰的边界分隔开。下部层段由斜层状、厚的红岩到浮岩层组成，主要由各种大型的纳姆莫利石测试组成，表明巴顿时代早期（浅底栖区 17）。相反，上部层段由珊瑚浮石到红石组成，并带有堆积石基质，富含与腹足动物、双壳类和罕见的小型大型底栖有孔虫相关的分支珊瑚。Heterostegina sp.的外观。该区间内的Glomalveolina ungaroi表明巴顿纪晚期（浅底栖区 18）。通过整合生物地层学和稳定同位素数据，较低的区间（具有丰富的纳木石）与MECO事件有关，在此期间较高的海面温度似乎促进了更大的底栖有孔虫的增殖，就像早始新世已经发生的那样。然而，在巴托世晚期，急剧转变为以珊瑚为主的碳酸盐工厂，罕见的大型底栖有孔虫表现出较小的尺寸，这可能是由于温度下降创造了更有利于珊瑚的条件。总体而言，这项研究提供了令人信服的证据，证明环境变化如何影响海洋碳酸盐的产生，还强调了研究这些关系的重要性，以更好地了解过去、现在和不久的将来的气候变化。

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During the Eocene, shallow-water carbonate systems were significantly impacted by climate fluctuations and hyperthermal events. Following the peak temperatures of the Early Eocene Climatic Optimum (EECO), a general cooling trend began, with short-lived (⁓200 kyr) warming events occurring alongside it. In the early Bartonian (around 40.1 Ma), a warming event known as the Middle Eocene Climatic Optimum (MECO) occurred, lasting approximately 500,000 years. In this scenario, the types and calcification rates of marine organisms such as corals and larger benthic foraminifera (LBF) were influenced by global CO2 and oceanographic changes, which had a major effect on photic carbonate factories. To better understand the effects of these factors on carbonate factories, a detailed study of shallow-water facies types, distributions, and evolution was conducted. The Middle Eocene Monte Saraceno sequence, located on the eastern margin of the Apulia Carbonate Platform (Gargano Promontory, southern Italy), was selected as a case study to investigate the relationships between carbonate factory types and climatic changes around the MECO event. This study identified two distinct intervals with different modes of carbonate production, separated by a sharp boundary. The lower interval consists of clinostratified, thick beds of rudstone to floatstone, mostly made up of various large Nummulites tests, indicating an early Bartonian age (Shallow Benthic Zone 17). Instead, the upper interval consists of coral floatstone to rudstone with a packstone matrix, rich in branching corals in association with gastropods, bivalves, and rare small larger benthic foraminifera. The appearance of Heterostegina sp. and Glomalveolina ungaroi in this interval indicates a late Bartonian age (Shallow Benthic Zone 18). By integrating biostratigraphic and stable-isotope data, the lower interval, with abundant Nummulites, was linked to the MECO event, during which higher sea-surface temperatures seem to enhance larger benthic foraminifera proliferation, as already occurred in the Early Eocene. However, in the late Bartonian, the sharp transition to a coral-dominated carbonate factory, with rare larger benthic foraminifera showing smaller sizes, could be attributed to a drop in temperature that created the conditions more favourable to corals. Overall, this study provides compelling evidence of how environmental changes can affect marine carbonate production, also highlighting the importance of investigating these relationships, to better understand climate change in the past, present and near future.