petrologist

例句：

1. 1. Petrology is the study of rocks and minerals.
   岩石学是研究岩石和矿物的学科。
2. 2. The petrologist discovered a new type of mineral in the area.
   这位岩石学家在该地区发现了一种新的矿物。
3. 3. Petrology plays an important role in understanding the Earth's history.
   岩石学在理解地球历史中起着重要作用。