挪威地质调查局Morten Smelror团队取得一项新进展。他们对Iapetus海洋亚热带Laurentian边缘的低温多毛类动物的研究，提供了冷水海洋环流和上升流的证据。相关论文于2024年9月12日发表在《地质学》杂志上。

据了解，显生宙以来，由多毛纲类动物钻孔沉积物形成的遗迹化石Macaronichnus，似乎局限于中纬度和高纬度的浅海栖息地，那里有寒冷到温带的水域或者靠近赤道的沿海地区，且具有冷水上升流。

该团队对挪威Caledonides中部奥陶系的浅水和深水海相沉积进行了研究，该研究指向以前没有记录的沿亚热带东部Laurentian边缘和邻近的火山弧，以及早古生代Iapetus海洋的微大陆深海环流和冷水上升流。本研究结合古地理重建和古气候模式，阐述了中奥陶世海洋环流模式的可能含义。

附：英文原文

Title: Cryophilic polychaetes at the subtropical Laurentian margin of the Iapetus Ocean: Evidence for cold-water ocean circulation and upwelling

Author: Morten Smelror, Tor Grenne, Reidulv Be, Deta Gasser, Terje Solbakk

Issue&Volume: 2024-09-12

Abstract: Through the Phanerozoic eon, the trace fossil Macaronichnus—made by sediment-burrowing polychaetes—appears to be restricted to intermediate- and high-latitude shallow-marine habitats with cold to temperate waters or coastal areas closer to the equator with cold-water upwelling. We present records of such trace fossils in Ordovician (Darriwilian-Sandbian) shallow- and deep-water marine deposits in the Central Norwegian Caledonides, pointing toward previously undocumented deep-ocean circulation and upwelling of cold water along the subtropical eastern Laurentian margin and adjacent volcanic arcs and microcontinents in the early Paleozoic Iapetus Ocean. Possible implications for Middle Ordovician ocean circulation patterns are discussed in relation to paleogeographic reconstructions and paleoclimatic models.

DOI: 10.1130/G52533.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52533.1/648382/Cryophilic-polychaetes-at-the-subtropical