pushed in from every side, carried a long ways

[KLPNO]

Hello everyone
I'd like to ask about the phrases "pushed in from every side" and "carried a long ways under the sea" in the following passage.

"Of course, there's no actual mountain there," she admitted. "It's just a flat plain shoved high by a set of faults and buoyant substrates. But there was a time, long ago, when the Continent pushed in from every side, and an entire island was buried. Buried and carried a long ways under the sea."

Is the phrase "when the Continent pushed in from every side" passive in this case, and does it mean that the Continent was completely surrounded by other bodies/islands and these island were pressing the Continent?

And does the phrase "carried a long ways under the sea" mean that the island was moving under water for a very long time?

[Anglika]

It seems that there was a body of water surrounded by "the Continent". The Continent pushes inwards, forcing the island under the water. The island then is pushed under the water for a great distance.