Gravel Specimens from the National Mall, 2009

Gravel from the National Mall, Washington, D.C. Collected 19th January, 2009.

Part of the McMillan Plan the gravel walkways encompassing the National Mall are a laid with a pleasing, naturally rounded limestone pebbles, tawny ochre in color, complimenting both the rich red of the seneca sandstone Smithsonian Castle and the somewhat severe Neoclassicism of the James Russell Pope designed National Gallery.

The National Mall as it appears today owes its design to the McMillan Commission, named for Sen. James McMillan of Michigan who was chairman of the Committee on the District of Columbia. Some of the greatest American architects, landscape architects and urban planners of the day served on the McMillan Commission, including Daniel Burnham, Frederick Law Olmsted, Jr., Charles F. McKim, as well as noted sculptor Augustus Saint-Gaudens, who worked to fully implement the original design for the National Mall by Pierre Charles L'Enfant.

Gravel aggregates are harvested from both glacial and alluvial natural deposits including limestone, granite, trap rock and other durable minerals. These are then processed by a series of crushing, screening, blending and washing operations. Large gravel deposits are a common geological feature, formed as a result of the weathering and erosion of rocks. The action of rivers and waves has tended historically to pile up gravel in large accumulations.

Etymology

The word gravel comes from the French gravelle, meaning “coarse sand”.