Earth science .

read the following scenario and answer in complete sentences.
you are an archaeologist 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 they formed from must have had a low viscosity but a high gas content. you also determine that some rock is basalt. what kind of volcano have you discovered? describe in detail how that volcano formed.