Question

QUESTION 8 Chapter 3.2.1. True/False: Magmas like rhyolite with high Sio2content tend to have a high viscosity (resistance to flow), while magmas like basalt with low SiO2content tend to have a low viscosity and flow very easily. O True False QUESTION 9 Chapter 3.2.1.Box 3.2. What is a continental flood basalt province? e a When a lava flow causes a river to be dammed, resulting in a flood. Ob-A massive lava flow at mid-ocean ridges that produces new oceanic crust. c, when basalt lava flows cover very large areas of continental crust. O d. A very low viscosity lava flow that fills an impact crater QUESTION 10 Chapter 3.2.2. Which combination of viscosity and gas content of the magma is most likely to lead to a very explosive volcanic eruption? O a low viscosity, low gas content O D low viscosity, high gas content c, high viscosity, low gas content o d high viscosity, high gas content

Answer 1

Answer:

Question 8 is true .

Question 9, the correct answer is c, when basalt lava flows cover very large areas of continental crust.

QUESTION 10, the right option is d high viscosity, high gas content.  

Explanation:

The viscosity of magma depends on its temperature, composition and gas content. Thus, magma with high levels of Sio2, silicon dioxide or silica increases the resistance flow as it increases lava viscosity, due to greater degrees of “internal friction”. Whereas basalt magma has a low-silica composition and flow fairly easily.  

The Earth’s surface is transformed by high volume eruptions made of basaltic lava. Convection currents in the mantle find their way to the surface in randomly generated hot spots covering vast areas of lands. The geothermal conditions of these provinces affect their geography.  

The volcanic explosiveness relies on the amount of gas and the degree of viscosity of magma. That is to say that high levels of gas mixed together with high viscosity rate result in highly explosive bursts. The eruptive force correlates to the internal pressure and the expansion of gas due to the friction caused by the resistance to flow.