a layer of rock, soil, or other material that lies on top of another layer

The earth consisted of a layer of strong yellow clay beneath a superstratum of fine loam measuring about ten inches deep. 泥土层包含了一层坚固的黄色粘土，以及上面约10英寸深的细土覆盖层。

one of the levels into which something is separated that is above another level

There will always be a superstratum of people who have more rights or power than the rest of us. 总会有一些处在上层的人比我们其他人拥有更多的权利或权力。