Geologic events that occurred during the paleozoic era include mountain building and volcanic activity. true or false.

The right answer is true.

In the middle of the Ordovician (one of periods of the Paleozoic era), Iapetus continued to close. The island volcanic arc off Laurentia collided with the Laurentia margin. It is a collision of oceanic plate type against continental plate: an immature mountain range has formed; this chain, the Taconian chain, was called the first phase of the formation of the Appalachians.

During this same period, the seas are still expanding and new sedimentary basins are forming. Great volcanic activity producing layers of lava and ash. The North American Appalachian mountain range springs up.

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.