Describe the geological structure presented in 'Рисунок 4'.

In 'Рисунок 4', the geological layers are represented according to the legend. The top layer is a 'гранитный слой' (granite layer), shown with dots. Beneath it is an 'осадочный слой' (sedimentary layer), depicted with horizontal dashes. The bottommost layer is a 'базальтовый слой' (basalt layer), indicated by 'v' shapes and small triangles.