DETRITAL ZIRCON ANALYSIS OF THE SEDIMENTARY RECORD

Abstract

The composition of “heavy,” or accessory, detrital minerals in sediments and sedimentary rocks has been a topic of quantitative study for at least the last seventy years, beginning with the first issue of the Journal of Sedimentary Petrology in May 1931 (Tyler 1931, Pentland 1931). Zircon has since played a prominent and complex role in interpreting the composition and history of modern and ancient sediments. Because zircon is highly refractory at Earth’s surface, it occurs in virtually all sedimentary deposits and so provides a critical link in understanding the source history of a deposit. Twenhofel (1941), in a pioneering paper on the frontiers of sedimentary mineralogy and petrology, noted that the simple presence of detrital zircon would be of little value in determining its source: “Zircons from a half dozen sources with as many different properties may be present in a sediment and merely be identified as zircon. Parent rocks cannot be positively identified on such data. The variety or varieties must be identified and their optical properties determined.” From very early on, then, it was recognized that detrital zircon would be a powerful tool in understanding provenance, and thus, sedimentary dispersal systems.