And so this is another lithographic milestone here that's helped to preserve it.

因此，这是另一个有助于保存它平版印刷里程碑。

ICC does buy US made steel but says imports bridge a gap in supply for high-grade tinplated steel needed for blemish-free lithographic printing.

独立金属司确实购买了美国产生铁，但时也表示，进口可以弥补高档镀锡应缺口，而高档镀锡正是无瑕疵平版印刷所需要原材料。

And what we see is extremely regular thin beds that extend for kilometers and exceptional preservation of soft-bodied material in what's called lithographic siltstone.

我们看到是极其规则薄层，绵延数里，并且在所谓平版粉砂岩中保存了特殊软体材料。