『This webpage has been stimulated by a paper by H.C. Sheth entitled “Large Igneous Provinces (LIPs): Definition, recommended terminology, and a hierarchical classification", accepted for a forthcoming special issue of J. Volcanol. Geotherm. Res. 』

『Introduction

The term “Large Igneous Province” (LIP) was initially proposed by Coffin & Eldholm (1994) to represent a variety of mafic igneous provinces with areal extents >0.1 Mkm² that were “massive crustal emplacements of predominantly mafic (Mg and Fe-rich) extrusive and intrusive rock, and originated via processes other than ‘normal’ seafloor spreading”. The initial database upon which the term LIP was defined relied almost exclusively on the relatively well-preserved Mesozoic and Cenozoic record that comprised continental flood basalt provinces, volcanic passive margins, oceanic plateaus, submarine ridges, seamount groups and ocean basin flood basalts (e.g., Coffin & Eldholm, 1994, 2005). Since the first categorisation of LIPs, substantial progress has been made in extending the LIP record back to the Paleozoic, Proterozoic and Archean (Ernst & Buchan, 1997; 2001, 2003; Tomlinson & Condie, 2001; Arndt et al., 2001; Isley & Abbott, 2002). For many ancient LIPs, where much or all the volcanic component of the LIP has been lost to erosion, definition has to be based on the areal extent and volume of intrusive rock (e.g., giant continental dyke swarms, sills, layered intrusions), which is the exposed plumbing system to the province. In addition, it has additionally been recognised that LIPs are also massive crustal emplacements of predominantly silicic (>65 wt% SiO2) extrusive and intrusive rock that have originated via processes other than ‘normal’ seafloor spreading or subduction (see Bryan et al., 2002). Consequently, the increasing realisation that LIPs are more varied in character, age and composition than first defined has prompted others to revise and broaden the original definition of LIP (Sheth, 2006; click here for a webpage summary of this paper). 』

Figure 1. Proposed classification of LIPs, based on the initial work of Coffin & Eldholm (1994), but incorporating recent advances in the recognition of ancient Mafic LIPs and Silicic LIPs. Representative examples of the various types of LIPs are given. 〔Bryan & Ernst（2006）による〔『Proposed Revision to Large Igneous Province Classification』から〕