The sample consisted of pebbles of hardened sediment that had once been soft, deep-sea mud, as well as granules of gypsum and fragments of volcanic rock.

这一样本包括曾经柔软的的硬化沉积物的卵石、深海淤泥以及石膏颗粒和火山岩碎片。

youdao

Oh well, that's all as clear as mud, then.

哎呀，那么一来这真是成了一本糊涂账了。

《牛津词典》

As part of that process they had to replace the dense drilling mud, which was used to keep the well under pressure while it was drilled, with sea-water.

在封井过程中，他们必须把用于在钻探过程里，保持钻井与海水压力相当的高密钻井泥更换掉：因为上方的海水的压力低于底下油气的压力。

youdao

The BP company pumped heavy drilling fluids,known as mud, into the top of its damaged well in the Gulf of Mexico.

VOA: special.2010.08.07

When the heavy drilling mud that provides the pressure needed to keep things from coming up the well was removed, first as a test, then as part of a procedure for closing down the well and moving the rig, telltale signs that something was wrong were missed.

ECONOMIST: BP casts the blame for the Gulf oil spill widely