Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival-Time Data Sets ...

• Main Authors: Liddell, MV, Bastow, I, Rawlinson, N, Darbyshire, F, Gilligan, A, Watson, E
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2018
• Subjects: seismic tomography; relative arrival time; cratonic lithosphere; Precambrian tectonics; Trans-Hudson Orogen; source side effect; Canada; Hudson; Hudson Bay; Nunavut
• Online Access: https://dx.doi.org/10.17863/cam.32107; https://www.repository.cam.ac.uk/handle/1810/284735

AbstractThe geology of northern Hudson Bay, Canada, documents more than 2 billion years of history including the assembly of Precambrian and Archean terranes during several Paleoproterozoic orogenies, culminating in the Trans‐Hudson Orogen (THO) ∼1.8 Ga. The THO has been hypothesized to be similar in scale and nature to the ongoing Himalaya‐Karakoram‐Tibetan orogen, but the nature of lithospheric terrane boundaries, including potential plate‐scale underthrusting, is poorly understood. To address this problem, we present new P and S wave tomographic models of the mantle seismic structure using data from recent seismograph networks stretching from northern Ontario to Nunavut (60–100 ∘ W and 50–80 ∘ N). The large size of our network requires careful mitigation of the influence of source side structure that contaminates our relative arrival time residuals. Our tomographic models reveal a complicated internal structure in the Archean Churchill plate. However, no seismic wave speed distinction is observed across ...