Final answer:
Landforms formed by molten materials are often referred to as volcanic blocks, which can include formations such as undersea ridges and mountains that arise from various types of volcanic activities.
Step-by-step explanation:
Landforms formed by molten materials are volcanic blocks. When lava rises to the surface through volcanoes, it can form various structures such as mid ocean ridges, which are undersea mountain ranges, as well as mountains associated with subduction zones. Not all volcanic eruptions create towering landforms; some eruptions result in the spread of lava across vast plains, as seen with the Snake River basalts or the Deccan plateau. Each type of volcanic activity provides insights into the geologic activity below our planet's crust.