CAREER: Environmental Forcing on the Resilience of Carbonate Platforms During the Early Cretaceous Super Greenhouse Period

浅海珊瑚礁系统支持着高度多样化的群落。然而，这些碳酸盐生产系统中约75%受到持续变暖和人类活动增加的威胁。调查地球的历史可以增加对这些脆弱系统的了解，并为确定缓解过程提供机会。大约1.2亿年前，大气中温室气体的含量急剧增加。在这样的条件下，浅海碳酸盐生产生态系统要么存活下来，要么适应，要么消失。这项提议将通过考察从古代赤道到亚热带的不同纬度的四个地点，来检验碳酸盐生产生态系统的弹性在低纬度受到青睐的假设。该项目将包括为从当地社区大学招收的未被充分代表的少数民族学生提供研究机会。这些学生将参加暑期实习计划，该计划包括多层次的指导方法，旨在增加对地球科学的兴趣和留住该专业的学生。学生将有机会发表他们的研究成果，并成为其他少数民族学生的榜样。该项目将通过调查法国、意大利和阿曼保存的碳酸盐平台，将生态系统的适应与海洋缺氧事件(OAE)1a相关的环境恶化联系起来。这些地区在OAE1a期间位于不同的纬度，经历了不同的气候和风化条件。碳酸盐台地要么在高古纬度消失，要么在次季风环境中转变为微生物群落。确定有利于这些生态系统恢复能力的参数需要确定碳循环和与OAE1a相关的化石组合中的扰动，并使用地球化学指标评估相关的环境压力。完成这些任务将加深对环境和碳酸盐生产之间反馈机制的了解，量化超级温室条件下的温度和营养纬度梯度，并提高对生态系统在全球古海洋扰动期间的弹性的理解，这可能有助于减缓现代珊瑚礁系统的灭亡。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Shallow marine reef systems support a highly diversified community. Yet, approximately 75% of these carbonate-producing systems are threatened by ongoing warming and increased human activity. Investigating the Earth's history can increase understanding of these vulnerable systems and provide opportunities for identifying mitigation processes. About 120 million years ago, the atmospheric content of greenhouse gases increased dramatically. Under such conditions, shallow marine carbonate-producing ecosystems either survived, adapted, or disappeared. This proposal will test the hypothesis that the resilience of carbonate-producing ecosystems was favored at low latitudes by examining four locations at different latitudes, from the ancient equator to the subtropics. This project will include research opportunities for underrepresented minority students recruited from a local community college. The students will participate in a summer internship program that includes a multitiered mentoring approach and is designed to increase interest in geoscience and retention in the major. Students will have the opportunity to publish their research and serve as role models for other minority students.This project will link the adaptation of ecosystems to environmental deteriorations associated with the Oceanic Anoxic Event (OAE) 1a, by investigating carbonate platforms preserved in France, Italy, and Oman. These areas were located at different latitudes during the OAE1a and experienced diverse climate and weathering conditions. Carbonate platforms either disappeared at high paleolatitudes or transitioned into microbial communities in subequatorial settings. Determining parameters that favor the resilience of these ecosystems requires the identification of the perturbations in the carbon cycle and in the fossil assemblage associated with the OAE1a, and the appraisal of associated environmental stresses using geochemical proxies. Achieving these tasks will deepen the knowledge on feedback mechanisms between the environment and carbonate production, quantify thermal and nutrient latitudinal gradients under super greenhouse conditions, and improve the understanding of the resilience of ecosystems during a period of global paleoceanographic perturbation that could serve to mitigate the demise of modern reef systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.