What separates the outer core from the mantle above it?

782

---

What makes mountains appear purple?

764

---

What is china clay?

776

---

Which of the earths interior layers have been drilled and sampled? What are the deepest drilling projects on record?

736

---

Which kind of volcano is the most destructive?

828

---

Which carbonate mineral reacts readily with cool dilute hydrochloric acid to produce visible bubbles of carbon dioxide gas?

752

---

What does regolith mean?

791

---

What is the rate of species and how does this relate to finding transitional species?

835

---

What is ablation?

759

---

What is the cambrian?

700

---

What are the three major types of rocks?

720

---

Where would you expect to find the oldest basalt on the floor of the atlantic ocean?

765

---

What is the mantle made of?

766

---

Describe the formation of igneous, sedimentary, and metamorphic rocks?

816

---

What is happening when a metamorphic rock is forming?

732

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