All of these minerals were probably originally transported to the earth’s surface as megacrysts in the alkali basalt. U-Pb age dating indicates the zircon has a crystallization age of 9.39 ± 0.4 million years.
All of these minerals were probablyoriginally transported to the earth’s surface asmegacrysts in the alkali basalt. U-Pb age dating indicatesthe zircon has a crystallization age of 9.39 ± 0.4million years.