Cover Image Credits

Cover Photo: Length of continental arcs (Cao and others, 2017 EPSL) and cumulative frequency of young zircons in detrital deposits (McKenzie and others, 2016 Science) indicate a peak period of continental arc flare-ups in Jurassic-Paleocene, when the carbon input from contact metamorphism is comparable to mid-ocean ridges (this study, p. 631–657).

Paper summary: In this issue (p. 631–657), Chu and others present a model of infiltration-driven decarbonation in contact metamorphic aureoles, and summarize a scaling relationship to relate steady-state carbon release to the infiltration flux. The model is combined with magmatic emplacement rate of continental arcs through time, to estimate the global CO₂ release by contact metamorphism at continental arcs. The result indicates that enhanced continental arc activities potentially contribute to warming over geologic timescales, especially during the late Mesozoic-early Cenozoic greenhouse interval.