You are an archeologist trying to determine the type of a volcano that erupted thousands of years ago. All you have are a few lava samples from the volcano's remains. You test your lava samples and determine that the magma that they formed from must have had a low viscosity but a high gas content. You also determine that some of the rock is basalt. What kind of volcano have you discovered? Provide evidence to support your answer including addressing the type of explosion and rock content.