EARTH-SCIENCE REVIEWS, vol.209, 2020 (SCI-Expanded)
Melanges represent a significant component of collisional and accretionary orogenic belts. We present a comparison of subduction-accretion melanges of different ages to test how melange-forming processes at convergent margins changed through time. We describe the Mesozoic McHugh melange in Alaska, and the Paleozoic Proto-Tethyan Laohushan melange of the Qilian Orogenic Belt of the Alpine-Himalayan chain, together with documentation of a Neoarchean melange that marks the suture between the Eastern Block and Central Orogenic Belt of the North China Craton (NCC). The McHugh is a classic accretionary melange that has not yet experienced a collision, and the Laohushan is an accretionary/collisional melange with structures related to both stages of its evolution. We compare the characteristics of these melanges with the world's largest Archean melange, the newly-documented circa 2.5 Ga 1600 km long Jianping-Zunhua-Zanhuang-Dengfeng (JZZD) melange of the North China Craton.