16) Describe and sketch the shape of the following volcanoes. Identify the differences in eruptive materials. A) Cinder cones B) Shield volcanoes C) Composite/stratovolcanoes

To describe and sketch the shapes of the three types of volcanoes—cinder cones, shield volcanoes, and composite (stratovolcanoes)—let's break down each type, including their characteristics and differences in eruptive materials. ### A) Cinder Cones **Description:** - Cinder cone volcanoes are the simplest type of volcano. - They are formed from the accumulation of volcanic debris, primarily cinders, ash, and small volcanic rocks ejected during explosive eruptions. - The shape is typically conical with steep sides, and they usually have a bowl-shaped crater at the summit. **Eruptive Materials:** - Primarily composed of small fragments of lava (cinders) that solidify and fall back to the ground. - Eruptions are usually short-lived and can be quite explosive. **Sketch:** ``` /\ / \ / \ / \ / \ /__________\ ``` ### B) Shield Volcanoes **Description:** - Shield volcanoes have broad, gently sloping sides and are shaped like a warrior's shield. - They are formed by the eruption of low-viscosity basaltic lava that can flow over great distances. - These volcanoes typically have a wide base and a less steep profile compared to cinder cones. **Eruptive Materials:** - Composed mainly of fluid basaltic lava flows. - Eruptions are generally non-explosive and can last for long periods. **Sketch:** ``` ______ / \ / \ / \ / \ / \ /________________\ ``` ### C) Composite/Stratovolcanoes **Description:** - Composite volcanoes, also known as stratovolcanoes, have a layered structure formed from alternating eruptions of lava flows, ash, and other volcanic debris. - They typically have steep, conical shapes and are characterized by a central vent or crater. - These volcanoes are often associated with more explosive eruptions. **Eruptive Materials:** - Composed of a mixture of lava flows (which can be andesitic to rhyolitic) and pyroclastic materials (ash, pumice, and volcanic rocks). - Eruptions can be highly explosive due to the higher viscosity of the lava. **Sketch:** ``` /\ / \ / \ / \ / \ / \ /____________\ ``` ### Summary of Differences in Eruptive Materials: - **Cinder Cones:** Primarily cinders and ash; explosive eruptions. - **Shield Volcanoes:** Fluid basaltic lava; non-explosive eruptions. - **Composite/Stratovolcanoes:** Alternating layers of lava and pyroclastic materials; can be highly explosive. These sketches and descriptions provide a clear understanding of the shapes and eruptive materials associated with each type of volcano.