Granulite facies metamorphic age and tectonic implications of BIFs from the Kongling Group in the northern Huangling anticline

We report preliminary results of a geochemical study on banded iron formations (BIFs) in the Zhaojiayangpo (赵家阳坡) area from the Kongling (崆岭) Group in the northern Huangling (黄陵) anticline, on the northern margin of the Yangtze craton. The CL (cathodoluminescence) images of zircons mostly have sector zoning, fir-tree zoning and patched zoning, and a few show core-rim tex- tures with rims having patched zoning. The calculated formation temperatures using the Ti-in-zircon