One of today’s major geoscientific controversies centres on the origin of the Archean granite‒greenstone terranes. Is the geology of these scattered remnants of our planet’s early crust consistent with the theory that modern-style plate-tectonic processes operated from the early Archean, or does it indicate that tectonic and magmatic processes were different in the Archean? Earth has clearly evolved since its initial formation, so at what stage did its processes of crustal growth first resemble those of today? The logical place to seek answers to these intriguing and important questions...