Contradictory Trends in the History of Cenzoic Corals and Coral Reefs: Oceanographic Change and Biotic Response

新生代珊瑚和珊瑚礁历史上的矛盾趋势：海洋变化和生物反应

• 批准号: 9909485
• 负责人: Jeremy Jackson
• 金额: $ 25万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-15 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909485&HistoricalAwards=false
• 关键词: Contradictory; Trends; History; Cenzoic; Corals

9909485JacksonA fundamental question in paleontology concerns the consistency of biotic responses to environmental perturbations that occur repeatedly but in different contexts in earth history. The aim of this research project is to document the response of Cenozoic Caribbean reef coral communities to changes in paleoceanographic conditions during two episodes of rapid biotic change. Large numbers of coral species became extinct during both the Early Miocene and Early Pleistocene, and extensive reef tracts disappeared from the Caribbean during the Early Miocene transition and did not return until after the Early Pleistocene extinction. Therefore, the regional development of constructional coral reef ecosystems is apparently not correlated with coral species diversity. This paradox suggests that these two episodes were associated with alternating paleoceanographic conditions. One model proposes a switch from predominant benthic to planktonic productivity during the Early Miocene followed by a switch back to more oligotrophic conditions during the Pleistocene. We will explore this hypothesis through rigorous documentation of the changing patterns of reef-coral diversity and by regional analysis of the biotic component of sediments.Exposures of Late Oligocene to Middle Miocene coral bearing rocks will be examined along an east-west transect extending from the gulf coast of North America to the windward isles. Large new collections of fossil corals will be made to supplement existing museum collections and a new database of species level occurrences will be compiled. This database will be added to the existing Late Neogene data to determine rates of species appearance and disappearance in the Northern Caribbean. The relative contribution of heterotrophic and phototrophic/mixotrophic organisms to near shore sediments provide a proxy for paleoproductivity that is independent of coral diversity. This will be evaluated using lithological samples from each of the study sites.

9909485杰克逊古生物学中的一个基本问题涉及到生物对环境扰动的反应的一致性，这些扰动在地球历史上反复发生，但在不同的背景下。 本研究项目的目的是记录新生代加勒比海礁珊瑚群落在两次快速生物变化期间对古海洋条件变化的反应。 大量的珊瑚物种在早中新世和早更新世灭绝，广泛的珊瑚礁在早中新世过渡期间从加勒比消失，直到早更新世灭绝之后才恢复。 因此，构造珊瑚礁生态系统的区域发展显然与珊瑚物种多样性无关。 这一悖论表明，这两个事件与交替的古海洋学条件有关。 一个模型提出了一个开关从主要的底栖生物到浮游生物的生产力在中新世早期，随后切换回更贫营养的条件下，在更新世。 我们将通过对珊瑚礁多样性变化模式的严格记录和对沉积物生物成分的区域分析来探索这一假设。我们将沿着从北美海湾海岸到迎风群岛的东西向断面，对渐新世晚期至中新世中期的含珊瑚岩石进行研究。 将收集大量新的珊瑚化石，以补充现有的博物馆收藏，并将编制一个新的物种一级的数据库。 该数据库将被添加到现有的晚第三纪数据，以确定物种出现和消失率在北方加勒比。 异养和光养/兼养生物的相对贡献，近海岸沉积物提供了一个代理的古生产力是独立的珊瑚多样性。 这将使用每个研究中心的岩性样本进行评价。