When a continental plate come to rest over a hot spot, the material rising from deeper layer creates a broad dome.
当大陆板块停留在一个热点上时，从深层升起的物质就会形成一个广阔的圆顶。
2
A thin layer of ice formed over the lake.
湖面上凝结了一层薄冰。
《新英汉大辞典》
3
To begin, soon after a dolphin sustains an injury such as a shark bite, surrounding blubber appears to extend a whitish layerover the exposed area to protect it.