Seismic Evidence for Crustal Modification Beneath the Hartford Rift Basin in the Northeastern United States
Seismic Evidence for Crustal Modification Beneath the Hartford Rift Basin in the Northeastern United States
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DOI：
10.1029/2020gl089316
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发表时间：
2020-09
影响因子：
5.2
通讯作者：
Haiying Gao;Xiaotao Yang;M. Long;J. C. Aragon
中科院分区：
文献类型：
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作者：
Haiying Gao;Xiaotao Yang;M. Long;J. C. Aragon
沿着北美东部边缘广泛的中生代裂谷形成了一系列盆地，其中包括新英格兰南部的哈特福德盆地。几乎同时，地理分布广泛的中大西洋岩浆省（CAMP）也被建立。哈特福德盆地为研究裂谷和岩浆作用在地壳演化中的作用提供了理想的场所，因为密集的 SEISConn 阵列和其他地震网络的集成提供了出色的台站覆盖范围。使用全波环境噪声断层扫描，我们构建了详细的地壳模型，揭示了哈特福德盆地下方的低速（Vs = 3.3–3.6 km/s）中地壳和高速（Vs = 4.0–4.5 km/s）下地壳。低速中地壳可能对应于由于裂谷期间的伸展和地壳变薄而产生的一层径向各向异性。高速地壳根可能代表 CAMP 事件造成的岩浆底侵残余。我们的发现揭示了与超大陆分裂、裂谷、伸展和岩浆作用相关的地壳变化。
Extensive Mesozoic rifting along the eastern North American margin formed a series of basins, including the Hartford basin in southern New England. Nearly contemporaneously, the geographically widespread Central Atlantic Magmatic Province (CAMP) was emplaced. The Hartford basin provides an ideal place to investigate the roles of rifting and magmatism in crustal evolution, as the integration of the dense SEISConn array and other seismic networks provides excellent station coverage. Using full‐wave ambient noise tomography, we constructed a detailed crustal model, revealing a low‐velocity (Vs = 3.3–3.6 km/s) midcrust and a high‐velocity (Vs = 4.0–4.5 km/s) lower crust beneath the Hartford basin. The low‐velocity midcrust may correspond to a layer of radial anisotropy due to extension and crustal thinning during rifting. The high‐velocity crustal root likely represents the remnant of magmatic underplating resulting from the CAMP event. Our findings shed light on crustal modification associated with supercontinental breakup, rifting, extension, and magmatism.