Linking ∼1.4–0.8 Ga volcano-sedimentary records in eastern Central Asian orogenic belt with southern Laurentia in supercontinent cycles

Abstract

The record of Meso- to Neoproterozoic magmatism and sedimentation from the western Xing’an-Airgin Sum Block (XAB), eastern Central Asian Orogenic Belt (CAOB), provides the first key evidence for the close affinity between XAB and southern Laurentia, as well as the linkage with the supercontinent cycles. The ∼ 1.4 Ga calc-alkline granite-rhyolite association within the western XAB was probably the product of extension on a long-lived retreating convergent margin during the Columbia breakup, remarkably similar to the coeval Granite-Rhyolite Province in the southern Laurentia. Siliciclastic, mixed clastic and carbonate sequences of the Airgin Sum Group accumulated on the western XAB during two stages at 1.00–0.92 and 0.87–0.75 Ga, which were comparable with the syn- to post-orogenic successions on the southern Laurentia margin representing two dominant phases of the Grenville orogenic cycle in the Rodinia assembly. The Columbia breakup to Rodinia assembly also correlated well with the shift of zircon Hf isotope from a long-term juvenile crustal growth (1.6–1.2 Ga) to the rapid crustal reworking (1.1–0.8 Ga), and with the changes of zircon trace elements over time in the western XAB. The ever-growing new discovery of predominant 1.5–1.3, 0.9–0.8 Ga detrital zircon age peaks and coeval magmatism in many blocks worldwide suggests that they recorded much more intense magmatic activity, exhumation and deposition than previous thought. Juvenile crustal growth underestimated in previous researches, occurred extensively in blocks within the CAOB and Columbia at ∼ 1.5–1.3 Ga, and crust reworking significantly dominated the crustal evolution during the Rodinia assembly in 1.1–0.8 Ga.