Question: Freeport, Maine is home to the tract of glacial silt that is of what measure?
Context: Bruce Shingledecker (August 9, 1945 – January 8, 2007) was a notable Alaskan wildlife painter.  He was best known for his acrylic paintings of Alaskan wildlife, some of which included glacial silt for texture.  In addition to painting, he was also a composer and musician. Akuliarusiarsuup Kuua (Danish: "Sandflugtdalen" ) is a river and valley of the same name in the Qeqqata municipality in central-western Greenland.  Its source is the meltwater outflow from Russell Glacier, an outflow of the Greenland ice sheet.  The river is a tributary of Qinnguata Kuussua, the main river in the Kangerlussuaq area.  For most of its run, the river flows very slowly through the sandur basin of the valley, forming meanders amongst large fields of glacial silt quicksand.  The climate is polar continental, with the area receiving very little rainfall. Petersen Glacier is in Grand Teton National Park, Wyoming, United States.  The glacier is in a cirque to the west and above north Cascade Canyon at an altitude of approximately 10000 ft .  The glacier is named after Frank Petersen, one of the first mountaineers to climb Grand Teton in 1898.  Runoff from the glacier is heavy in rock flour (glacial silt) which turns the waters of Mica Lake turquoise in appearance.  The glacier is no longer visible in satellite imagery, indicating it may have disappeared.  All of the existing glaciers in Grand Teton National Park were created during the Little Ice Age (1350-1850) and have been in a general state of retreat since the mid-19th century. The Peyto Glacier is situated in the Canadian Rockies in Banff National Park, Alberta, Canada, approximately 90 km northwest of the town of Banff, and can be accessed from the Icefields Parkway.  Peyto Glacier is an outflow glacier from the Wapta Icefield, which rests along the Continental divide.  The glacier snout is subject to high melt rates from season to season and there is marked surface lowering on several parts of the glacier.  Glacial silt, which is carried from the glacier by streams, ensures a turquoise appearance to Peyto Lake, a popular tourist destination.  As is true for the vast majority of glaciers worldwide, Peyto Glacier has been retreating rapidly, especially since the last half of the 20th century, and has reportedly lost 70% of its mass since it was first researched (Demuth and Keller, 2006).  Between 1896 and 1966, the total volume loss of the Peyto Glacier was 1088.5 x 10 m (Wallace, 1995).  In 1987, an automatic weather station was constructed near the glacier that monitors temperature changes, radiation, and precipitation Delta Lake is located in Grand Teton National Park, in the U.S. state of Wyoming.  Delta Lake is situated in Glacier Gulch and is fed rock flour (glacial silt) from the Teton Glacier, which turns the water turquoise in appearance. Freeport is a town in Cumberland County, Maine, United States.  The population was 7,879 at the 2010 census.  Known for its numerous outlet stores, Freeport is home to L.L. Bean, Wolfe's Neck Woods State Park, and the Desert of Maine. The Presumpscot formation is a late Pleistocene glacial deposit of predominantly submarine clays, located along the Maine and New Hampshire coast and inland along their major river valleys.  It consists of primarily silt- and clay-sized particles formed from the glacial abrasion of the feldspars, quartz, and micas of the region, carried by glacial meltwater and deposited below sea level before subsequent crust rising (isostatic rebound) elevated the deposits up to more than 300 ft .  It is named after the Presumpscot River where large amounts of the characteristic blue-gray clay are found. Saint David's Buried Gorge is an ancient pre-glacial river bed that existed 22,800 years ago on the present-day Niagara Peninsula.  The ancient Saint David's River once flowed through this area prior to the advance of the Wisconsin Glacier during the last glacial period.  When the glacier retreated 12,000 years ago, the gorge and river valley were filled in with glacial silt and rocks.  Approximately 4,200 years ago, the Niagara River intersected the buried gorge in the course of Niagara Falls receding toward Lake Erie.  When the river encountered the soft glacial silt that filled the gorge, the river rapidly changed course to fill the ancient gorge and wash out most of the silt.  This led to the formation of the Niagara Whirlpool.  The Niagara River reclaimed the gorge and currently flows through part of the ancient gorge.  The other part of the ancient gorge extends into Lake Ontario at a different point than the Niagara River.  The gorge is estimated to be 4000 ft long, 1000 ft wide, and 300 ft deep. Freeport Area School District (FASD) in Pennsylvania, United States is home to the Yellowjackets and Buffalo Elementary School, South Buffalo Elementary School, Freeport Area Middle School, and Freeport Area High School.  Buffalo Elementary School, the Freeport Area Middle School, and the Freeport Area High School, along with the Administration building, are in Sarver, Butler County, and South Buffalo Elementary School is located in South Buffalo Township, Pennsylvania in Armstrong County.  In 1969, the political divisions of Freeport, Buffalo and South Buffalo merged to form the Freeport Area School District.  FASD lies along the banks of the Allegheny River and is on the mouth of Buffalo Creek.  It is located about 25–30 miles north of Pittsburgh, Pennsylvania.  The community is a mix of Pittsburgh suburbia and rural areas. <BR> The Desert of Maine is a 40 acre tract of exposed glacial silt (a sand-like substance, but finer-grained than sand) surrounded by a pine forest near the town of Freeport, Maine, in the United States.  The Desert of Maine is not a true desert, as it receives an abundance of precipitation, and the surrounding vegetation is being allowed to encroach on the barren dunes.
Answer: 40 acre