Christine Legere J.E. Hughes Clark J.T. Kelley Walter Barnhardt Brian Andrews D.F. Belknap Laura L. Brothers 2016 <p><span>Pockmarks are seafloor depressions associated with fluid escape (</span><span class="xref-bibr">Judd &amp; Hovland 2007</span><span>). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (</span><span class="xref-bibr">Ussler <i>et al.</i> 2003</span><span>; </span><span class="xref-bibr">Rogers <i>et al.</i> 2006</span><span>; </span><span class="xref-bibr">Wildish <i>et al.</i> 2008</span><span>). In North America, shallow-water pockmark fields are not reported south of Long Island Sound, despite the abundance of gassy, muddy estuaries. The absence of pockmarks south of the limit of North American glaciation suggests that local and regional heterogeneities, possibly related to glacial or sea-level history or bedrock geology, influence pockmark field distribution. In shallow-water embayments, such as Passamaquoddy Bay, New Brunswick, pockmarks can be large (&gt;200 m diameter) and number in the thousands.</span></p> application/pdf 10.1144/M46.60 en The Geological Society Pockmarks in Passamaquoddy Bay, New Brunswick, Canada article