Meaning on the bottom is mud, then a layer of something they presume to be oil, and on top of that a two-inch thick goop that Asper calls "slime snot," possibly made up of oil and bacteria.

这条纹状泥土底层是烂泥，其上一层科学家估计可能是原油。再往上(也就是最上面)是两英尺厚的粘稠物，Asper称其为——粘稠的鼻涕(译者注：看起来很恶心啊，这科学家幽默感不好啊)，这粘稠物极有可能是由原油和细菌组成的。

youdao

The quality of water is really bad, lack of inner current and thick layer of mud prevent valuable flora and fauna from creating an actual micro-cosmos.

内部循环和厚层泥土的缺乏导致动植物稀少，无法创造真正的微气候环境。

youdao

Unfortunately, between the island there was a layer of soft mud, 27 meters thick in places.

不走运的是，在岛之间有一层软泥，27米厚在那个地方。

youdao

The explosions were accompanied by heavy rain, leaving the island's roads coated in a thick layer of mud.

BBC: Ash rains down on Montserrat