This down-strike , in addition to the digging the trench , split a large piece of quartzite ( about 18 in or 0.5 m across -- see inset ) and damaged three small trees .

雷击除了挖沟以外，还劈开了一大块的石英岩（跨度约为18英寸（0.5米）--看插图），并损坏了3棵小树。