gravel layer

The sand or gravel layer should be put over this clay.

The media is either in suspension or supported by a gravel layer at the foot of the filter.

The flakes found in the gravel layer may be zoofacts, created by the actions of animals.

In addition, the gravel layer contains many flakes.

A layer of clay particles placed under the gravel layer is beneficial.

The gravel layer with a thickness of up to 10 m, was deposited by the Meuse, which repeatedly moved to the east.

The pit leads to a gravel layer beneath, resulting in highly radioactive water pouring directly into the sea.

Below the sand is a layer of smaller gravels called the separating gravel layer.

The sand overlays a 4-inch gravel layer.

The theory is that gophers tunneling into loose soil run into a gravel layer below.

Sometimes a drywell with a series of gravel layers near the lowest spot in the rain garden will help facilitate percolation.

This prevents filtration sand from entering the drainage gravel layer and clogging the outlet tube.

Sand-based systems are composed of a sand-based root zone, a gravel layer, and a drainage system.

The site was periodically sealed by gravel layers and Paleosols, ancient soils preserved by burial under more recent sedimentation.

The name Álfheim here may have nothing to do with Álfar 'Elves', but may derive from a word meaning 'gravel layer'.

Following the February 2010 burials, the headstones were installed, and the limestone and gravel layer covered with topsoil and turfed with grass.

During the advances and withdrawals of the glaciers, gravel layers were deposited in the valleys, sometimes quite thick, though most of it eroded in the subsequent interglacials.

Under this shallow gravel layer (in many places it is only a metre or so down) is a hard granite layer that is the base rock of the hills district.

Overlying these sediments are Pliocene to Pleistocene colluvial, alluvial, and nearshore marine sands, silts, and clays that contain occasional gravel layers.

Most rain gardens are designed to be an endpoint of drainage with a capacity to percolate all incoming water through a series of soil or gravel layers beneath the surface plantings.

But when scientists began looking for blind thrust faults several years ago, Dr. Dolan said, they could only infer the existence of them from folds in sand and gravel layers near the surface.

"When I explained that the matrix would allow the roots to move out beneath the sidewalk, rather than up through that gravel layer, looking for moisture and air, their ears perked up," she said.

Instead of the anaerobic gravel layer of old style aquaria, this now becomes a biologically active aerobic medium supporting bacteria which decompose organic matter to carbon dioxide and water and oxidize ammonia to nitrate.

Right below this separating layer is the drainage gravel layer, which supports the separating gravel layer and helps water flow by preventing clogging near the base of the outlet tube.

In August of 1961, Larry Kickels collected the third right upper molar of a Jefferson mammoth from a gravel layer 100 feet below the surface of Berrien County, near the town of Watervliet.