Intermediate lavas can flow slowly or not easily than mafic lavas due to the high viscosity.
The reason is flow and the viscosity are inversely proportional to each other, it means if the viscosity is low, the flow of liquid or lava is high and if the viscosity is high flow is slow.
Mafic or basaltic lava is less viscous than intermediate lava, so mafic lavas flow easily than intermediate lava.
