but slowly disintegrating. 却是在慢慢地崩塌

137. but on a much longer timescale.
     可是不会持续多久
138. These loose boulders are the mountain's crumbling bones.
     这些散落的石块是从山脊上崩裂下来的
139. The Rockies are no longer rising
     落基山脉已不再上升
140. but slowly disintegrating.
     却是在慢慢地崩塌
141. All mountains everywhere are being worn down by frost, snow and ice.
     世界各地的高山都在不断经受 森林、积雪和冰川的消蚀
142. The Alps were raised some 15 million years ago
     阿尔卑斯山崛起于1500万年前
143. as Africa, drifting northwards, collided with the southern edge of Europe.
     原因是非洲板块向北漂移 与欧洲南麓相撞

来自《行星地球 第一季 第二集 Planet Earth S01E02 山地》第 140 行