Abstract Mineral inclusions in zircon from gneisses in the ultrahigh‐pressure (UHP) zone of the Dabie Mountains, China, are studied by using laser Raman spectrophotometry. We identified numerous ...

Laboratory data of velocity (Vp and Vs) and quality factor (Qp and Qs) of a large number of charnockites and associated granitoid gneisses of Kudankulam are reported in this article. The results show ...

Frost agrees. The 3.8-billion-year-old zircons in the Michigan and Wyoming gneisses hint at older rocks that were either recycled in Earth’s mantle or remain buried in the crust.

Gneiss is a metamorphic rock composed of bands and lenses of various minerals, according to Geology.com. "Our candidates for the oldest U.S. rock are ancient gneisses with complex histories.

Michigan, Minnesota and Wisconsin all feature ancient rocks known as gneisses — metamorphic rocks banded with various minerals — but an analysis determined that the gneiss in northern Michigan ...