Trilobites and zircons link north China with the eastern Himalaya during the Cambrian

Abstract

A paucity of integrative data can lead to disparate pre-Pangean paleogeographic reconstructions, such as those for the Neoproterozoic-Cambrian paleogeography of the blocks of modern-day China. Reconstructions for the north China block, in particular, have relied on sparse paleomagnetic and biogeographic data and, as a result, have yielded discordant paleogeographic models. Here we present new detrital zircon grain age distributions from siliciclastic rocks, coupled with species-level polymerid trilobite biogeography, that suggest close ties between north China and the northeastern Indian margin during the Cambrian. In combination, these data require north China to have been in paleogeographic continuity with northern India as a part of core Gondwanaland, contrasting with the traditional view that north China was an isolated outboard terrane. The shared record of Cambrian-Ordovician tectonism in both northern India and north China likely represents the same event, which affected this region of Gondwanaland. © 2011 Geological Society of America.