Large igneous provinces and explosive basaltic volcanism

Large igneous provinces are recognized from the Precambrian at 3.79 Ga (Ernst, 2013), and extend through well-preserved examples from the Mesozoic and Cenozoic (Ross et al., 2005; Bryan and Ferrari, 2013, and references therein). While originally inferred to consist of a layer-cake sequence of massive and laterally continuous effusive basaltic lava flows, detailed volcanostratigraphy studies have generated a more nuanced view of province architecture, highlighting that many provinces include a significant component of clastic material derived from volcanic and sedimentary formation mechanisms. Conversely, some of the volumetrically largest basaltic volcaniclastic deposits appear to be associated with large igneous provinces (Ross et al., 2005). The importance of volcaniclastic deposits - and the implications for paleoenvironmental reconstructions, eruption dynamics, and climate impact - is one of the key concepts to emerge from scientific studies of large igneous provinces over the last 25 years. Ross et al. (2005) recognized, and highlighted, the near-ubiquitous occurrence of mafic volcaniclastic deposits as an integral component in large igneous provinces. These deposits contain information - some unique - on primary fragmentation mechanisms, eruptive processes, and depositional environments. Mafic volcaniclastic deposits provide a record of what we now recognize as complex temporal and spatial volcanic heterogeneity in large igneous provinces, and allow us to reconstruct their tectonic and physical evolution as an equally significant and complementary story to that of the geochemical evolution of magmatism. We provide a brief overview of mafic volcaniclastic deposits and formation mechanisms, and spotlight recent work highlighting their utility for interpreting large-scale tectonic evolution and climate impact issues related to large igneous province emplacement.