The two versions of the Virgin of the Rocks

Viewed from a geological perspective, all of Leonardo’s paintings and drawings reveal a remarkable fidelity to nature.  The Virgin of the Rocks (Fig. 1,below) in the National Gallery in London, attributed to him, displays no such fidelity.  If we compare it to the Virgin of the Rocks in the Louvre (left photo), whose geological accuracy is astounding, we cannot help questioning whether Leonardo himself painted the background in the National Gallery painting.
Over the centuries, various arguments have called into question the attribution of the National Gallery painting to Leonardo.  Scholars have analyzed the brush strokes, undertaken document searches and tried to prove definitively that Leonardo painted the National Gallery work.  However, there have always been doubts and many unanswered questions concerning its authenticity.

Fig. 1 Virgin of the Rocks, National Gallery,London, 1503-08