The Ordovician volcanic rocks in the Mayaxueshan area have been pervasivelyaltered or metamorphosed and contain abundant secondary minerals such as albite, chlorite, epidote,prehnite, pumpellyite, actinolite, titanite...
Nd, Sr and O isotopic study on the spilite-keratophyre sequence in Xiqiu shows that its ∈_(Nd) values are inthe range of 4.02-5.26, and its ∈_(Sr) values, +1.4-2.6. According to the points of these data in the ∈_(N...