生物礁对海平面变化的响应——基于黔南晚石炭世大型珊瑚礁的海平面变化幅度估算

Response of Reefs to Sea-Level Change:Estimation of Magnitude of Sea-Level Change Based on the Late Carboniferous Large Coral Reef in Southern Guizhou

晚古生代冰期是地质历史时期一个重要事件,由晚古生代冰期引起的海平面变化对该时期的生物礁系统产生深远影响.主要讨论了晚古生代冰期背景下生物礁对海平面变化的响应.生物礁随海平面变化表现为三种生长模式,即“放弃”“跟随”和“追赶”.以黔南地区格舍尔期大型珊瑚礁为例对黔南地区海平面变化幅度进行计算,认为黔南地区格舍尔期海平面上升(60±5)m,主要由冰川作用引起.根据扁平村珊瑚礁对格舍尔期黔南地区海平面变化幅度计算的误差来源主要为基底沉降以及古水深估算不精确.造礁珊瑚Fomitchevella的形态以及快速生长的特点揭示了黔南地区格舍尔期气候温暖、海平面上升且海侵快速的古环境条件.扁平村珊瑚礁的发育反映了全球气候变化和相关的海平面波动与冰期有关.

The Late Paleozoic ice age is a vital event in the geological history.The sea level change caused by the Late Paleozoic ice age has a far-reaching impact on the reef system.The response of reefs to sea-level change in the context of the Late Paleozoic ice age is discussed.Reefs exhibit three primary modes of response:“abandonment”,“synchronization”,“persistence”.We calculated the rise of sea level in Gzhelian by the large Bianping coral reef in southern Guizhou.The sea level of Gzhelian in southern Guizhou rose by about(60±5)m,which is mainly caused by glaciation.The sources of error in this estimation chiefly revolve around basement subsidence and inaccurate estimation of paleo-water depth.The morphology and rapid growth characteristics of Fomitchevella reveal the paleoenvironmental conditions of warm climate,rising sea level and rapid transgression in the Gzhelian period in southern Guizhou.The development of the Bianping coral reef reflects the global climate change and sea level fluctuations are related to the ice age.