How do columnar joints form? What will be an ideal response?


In a lava flow, especially a mafic one, a distinctive pattern of columns bounded by fractures may form.
This occurs when the lava flow stops moving, contracts as it cools, and produces forces that cause
fractures to open. The fractures, called joints, appear as polygonal cracks that extend downward,
forming parallel columns with their long axes perpendicular to the cooling surface.

Environmental & Atmospheric Sciences

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Environmental & Atmospheric Sciences