COLUMNAR JOINTING IN BASALT

Fractures, Joints, Veins Primary structures, sedimentary, magmatic rocks

Basalt columns and columnar joints converge upwards in a Tertiary volcanic vent with an age about 14.07±0.37 Ma (K-Ar age, whole rock), north of Jijiazhuang village in the Chnagle area, Shandong province, China. Attitude of these converged BCCJ are possible related to upward conflux of basalt magma. PhotoID159

Photograph: Xing-Wang Xu

Reference: This is a Journal of Structural Geology Photograph of the Month (JSG in press)