Paleontological evidence of a brief global sea-level event during the last interglacial
Paleontological evidence of a brief global sea-level event during the last interglacial
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上一次间冰期期间短暂的全球海平面事件的古生物学证据
DOI：
10.1111/j.1502-3931.1998.tb00513.x
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发表时间：
2007
期刊：
影响因子：
1.5
通讯作者：
B. White
中科院分区：
文献类型：
--
作者：
Mark A. Wilson;H. A. Curran;B. White
在巴哈马圣萨尔瓦多和大伊纳瓜岛上的桑加米期(Eemian；海洋氧同位素亚阶段5E)礁相中，存在一个浅水钻孔和洞穴的平缓起伏的侵蚀面。对该海面上下珊瑚的精确U/Th测年结果表明，其形成于125-124ka左右，其形成的海平面海退-海侵旋回持续了1500年或更短时间。地表完全出现在碳酸盐岩上，地形低洼，点缀着在海平面低水位期间形成的侵蚀通道和岩溶洞穴。在低水位期间发育的一种古土壤，部分填充了一组大型食岩双壳类钻孔(胃虫鱼雷)，表明它们是在海退过程中被挖掘出来的。植物根系形成的根状结构出现在大伊纳瓜的侵蚀面上。在随后的海侵过程中，对向上的表面进行了广泛的钻探，包括一枚较小的G.鱼雷和一枚蛇形海绵钻探(Entobia Ovula)。钻探的表面覆盖着各种浅水珊瑚，最终是重建的岸障珊瑚礁。沟渠和洞壁上覆盖着稀疏的蛇形蠕虫和蠕虫腹足类管子。坚固的蛇形类洞穴系统出现在侵蚀表面以下和上方的珊瑚相的沉积物中。河道和洞穴中充斥着海侵的钙质沉积物，其中出现了许多蛇形和斯科石岩洞穴。侵蚀表面上、下和上面的遗迹化石是一个短暂但重大的全球海平面事件的突出指标。
A gently undulating to flat erosion surface with shallow-water borings and burrows is present in the midst of a Sangamonian (Eemian; marine oxygen isotope substage 5e) reefal facies on the islands of San Salvador and Great Inagua, Bahamas. Precise U/Th dating of corals above and below this surface show that it formed around 125-124 ka, and that the sea-level regressive-transgressive cycle which produced it lasted for 1500 years or less. The surface occurs on entirely carbonate rocks and has a low relief punctuated by erosional channels and karstic caves formed during the sea-level lowstand. A terra rossa paleosol, developed during that lowstand, partially fills a set of large lithophagid bivalve borings (Gastrochaenolites torpedo), showing that they were excavated during the regression. Rhizomorphs formed by plant roots occur on the erosion surface at Great Inagua. Extensive boring of the upward-facing surfaces occurred during the ensuing transgression, including a smaller G. torpedo and a clionid sponge boring (Entobia ovula). The bored surface is encrusted by a variety of shallow-water corals and, eventually, the re-established bank-barrier coral reefs. A sparse assemblage of serpulid worm and vermicularid gastropod tubes encrusted the channel and cave walls. Robust Ophiomorpha burrow systems occur within pockets of sediment in the coral facies both below and above the erosion surface. The channels and caves are filled with transgressive calcarenitic sediments in which occur numerous Ophiomorpha and Skolithos burrows. The ichnofossils on, below, and above this erosion surface are prominent indicators of a short-lived but significant global sea-level event.