Canadian shield is composed of Precambrian rocks that cover 2.8 million square miles.
i hope this helps you
from google:
"The Earth gets hotter as one travels towards the core, known as the geothermal gradient. Geothermal gradient is the amount the Earth's temperature increases with depth, indicating heat flowing from the Earth's warm interior to its surface. On average, the temperature increases by about 25°C for every kilometer of depth"
Answer:
Marble is a type of rock. It is a metamorphic rock , which means rock which as changed it texture or shape or color over the time. These rocks are formed usually by uniting already existing substances on the earth. Limestone is the naturally available stone , which when undergoes metamorphosis turns into the formation of marble. Marble forms when the hot magma heats the limestone , the heat recrystallizes the calcite in the limestone changing its texture, shape etc.