Inside that door is a chamber partly filled with loose gravel.
It went off the road onto loose gravel, the tires slipping.
He found a patch of loose dirty gravel and started rolling in it.
Off to the left, he picked out the scrape of footsteps on loose gravel.
She leaned against the car and kicked some loose gravel.
Boulders and loose gravel made it difficult to make easy progress.
Aside from a thin layer of loose gravel, it was solid rock.
As the dust began to clear, she saw that the driver hadn't allowed for the loose gravel on the road.
The loose gravel slid away under his feet like polished rice.
Their feet made no more noise on the loose gravel than if it was sand.