**7.4 Stage 4**

Continuous subduction and transgression shifted the sediments to the pelagic/ hemipelagic apron, representing the last stage of tectonosedimentary evolution of the Kolosh forearc basin. These are evident from suite of facies types of alternative thin beds of sandstone, siltstone, mudstone, and hemipelagic carbonate mud/marlstone cf. F1, F2, F3, F7. F11. Moreover, it is evident from bed geometry, sedimentary structures, and microfossils assemblages, such as radiolaria, planktonic foraminifera, and hemipelagic benthic foraminifera. This margin is characterized by silicified mudstone and discontinuous silica horizons.
