近日，美国南加州大学Gene Yogodzinski团队研究了西北太平洋板块天皇海山演化与大地构造。相关论文于2025年9月22日发表在《地质学》杂志上。

人们对西北太平洋板块白垩纪历史的认识依赖于构造重建，但由于该区域采样匮乏，这些重建缺乏年代学和地球化学约束。

研究组提供了明治、反正、绥靖及天智四座天皇海山样本的新年龄与成分数据。天智（66 Ma）和绥靖（70 Ma）的拉斑玄武岩年龄与预期年龄递进规律相符，而反正海山的粗面岩样本（66 Ma，预期年龄约73 Ma）代表了碱性盾后火山事件。从明治到绥靖海山呈现的海脊状形态和亏损型地球化学特征，以及底特律海山（约76 Ma）东南侧火山延伸脊（VERs）的年龄（78-75 Ma）与亏损成分，均与地幔柱-洋脊相互作用模式吻合。

这些火山延伸脊解释了最古老天皇海山预期火山体积缺失的问题。在底特律海山北部以东发现一个具有洋中脊玄武岩地球化学特征的小海山，其年龄为100 Ma，这为天皇海槽与停滞断裂带之间洋壳碎片提供了最小年龄限值。研究组提出沿天皇海槽存在约300公里的右行偏移来解释该古老地壳碎片的位置。该研究的新数据为认知度极低的夏威夷-天皇海山链早期演化及西北太平洋板块白垩纪静默带（白垩纪正极性超静期）的地球构造历史提供了关键约束。

附：英文原文

Title: Early Emperor seamount evolution and geotectonics of the northwestern Pacific plate

Author: Pilar Madrigal, Kaj Hoernle, Brian R. Jicha, Christian Timm, Dieter Garbe-Schnberg, William W. Sager, Folkmar Hauff, Maxim Portnyagin, Gene Yogodzinski

Issue&Volume: 2025-09-22

Abstract: Our knowledge of the Cretaceous history of the northwestern Pacific plate relies on tectonic reconstructions that lack geochronologic and geochemical constraints due to the paucity of sampling in this area. We present new age and compositional data for samples from four Emperor seamounts: Meiji, Hanzei, Suizei, and Tenji. Tholeiites from Tenji (66 Ma) and Suizei (70 Ma) yield ages consistent with the expected age progression, whereas a trachytic sample from Hanzei (66 Ma, expected age of ca. 73 Ma) represents an alkalic post-shield event. The ridge-like morphology and depleted geochemistry of Meiji to Suizei seamounts and the age (7875 Ma) and depleted composition of the volcanic elongated ridges (VERs) southeast of Detroit seamount (ca. 76 Ma) are consistent with plume-ridge interaction. The VERs account for the missing volume of volcanism expected from plume-ridge interaction for the oldest Emperor seamounts. A small seamount with mid-ocean ridge basaltlike geochemistry located east of northern Detroit seamount yielded an age of 100 Ma, representing a minimum age for the oceanic crustal sliver between the Emperor Trough and the Stalemate Fracture Zone. We propose ～300 km of dextral offset along the Emperor Trough to explain the location of this older crustal sliver. Our new data provide important constraints on the poorly known early evolution of the Hawaiian-Emperor Seamount Chain and the Cretaceous Quiet Zone (Cretaceous Normal Superchron) geotectonic history of the northwestern Pacific plate.

DOI: 10.1130/G53477.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53477.1/661409/Early-Emperor-seamount-evolution-and-geotectonics