Consider the following statements regarding volcanic cones : 1. Acid lava cones are formed during volcanic eruptions by extremely viscous lava. 2. Viscous lava has high mobility and can travel long distances. 3. Acid lavas result in steep-sloped tall cones. 4. Composite cones are the tallest of all volcanic cones. Which of the statements given above are correct?

Statements 1, 3 and 4 are correct. Acid lava cones form during volcanic eruptions from extremely viscous (silica-rich) lava. Because of high viscosity, acid lava does not flow far and piles up steeply around the vent, producing tall cones with steep slopes — hence statement 3 is correct. Composite cones (stratovolcanoes), built up by alternating layers of lava and pyroclastic material, are typically the tallest of all volcanic cones (e.g., Mt. Fuji, Mt. Kilimanjaro). Statement 2 is incorrect because viscous lava has LOW mobility (not high) and cannot travel long distances — basic lava (low viscosity) is the type that travels long distances.