How does the author imagine the formation of this amber? Say it in simple language.

One summer, a fly landed on a big pine tree. Suddenly, a spider came at me. At this time, a drop of turpentine dripped down and wrapped the fly and spider together. Turpentine continued to drip and accumulated into a turpentine ball. Later, water flooded the forest and turpentine balls were submerged under the sediment. Thousands of years later, turpentine balls became fossils.