Granites within São Francisco Craton comprising pinkish alkali-rich migmatite near Riacho Seco, Curaça, Bahia State (sample RF-261, model age of 3.59 and eNd (2.7 Ga) of -6.70), and mafic biotite ...

Rock outcrop of biotite gneiss at Watersmeet Dome in Michigan’s Upper Peninsula. Recent findings published in GSA Today suggest this formation, known as the Watersmeet Gneiss, may be the oldest intact ...

That led to a paper published in the Geological Society of America in April, examining the oldest of old rocks in Wyoming, Minnesota and Michigan, as well as identifying a new record holder in ...