Consider the following statements regarding Volcanic Cones : 1. During volcanic eruptions, acid lava cones are formed by highly viscous lavas. 2. Viscous lavas have high mobility and can travel for long distances. 3. Acid lavas result in the formation of high cones with steep slopes. 4. Composite cones are the highest volcanic cones. Which of the statements given above are correct ?

Acid lava is highly viscous (high silica content), so it does not flow easily and solidifies quickly near the vent, producing steep-sided, high cones — hence statements 1 and 3 are correct. Statement 2 is incorrect because viscous lavas have LOW mobility and travel only short distances; basic (basaltic) lavas are the ones that flow long distances. Composite (strato) volcanoes such as Fujiyama, Mount Mayon and Stromboli are indeed the tallest and most common large volcanic cones, formed by alternating layers of lava and pyroclastic material, so statement 4 is correct. Therefore statements 1, 3 and 4 are correct.