Two large linear magnetic anomalies bound a north-northwest–trending belt of folded middle to upper Paleozoic shelf and terrestrial sedimentary rocks on the western margin of the New England foldbelt. The Peel anomaly has an ultramafic source that lies along the Peel thrust fault, a structure separating shelf sedimentary rocks from paleozoic cherts, argillites, and metabasites. The Mooki anomaly occurs along the boundary of the shelf and terrestrial sediments where these strata are thrust against flat-lying Permian strata. The source of the Mooki anomaly is intermediate and mafic igneous rocks of uncertain age, which have been intruded along a complex thrust system. These findings have been briefly discussed in relation to broadly similar geology and large positive linear magnetic anomalies in California and New Zealand.