Arabia Mountain

Although there is little historical evidence about what existed in the lands that currently make up the National Heritage Area, by the time of Anglo-American settlement in the early 19th century, the area was sparsely populated by Muscogee (Creek) and Cherokee tribes. It is believed that the area was a buffer between the two nations, used as a trade and transportation corridor. The land was ceded to the state of Georgia by the Muscogee in 1821. The land was then distributed to settlers via the Georgia Land Lotteries. Throughout the rest of the 19th and most of the 20th centuries, the area remained very sparsely populated, with many of the roads remaining unpaved until the 1950s. This railroad supported Lithonia's quarry industry, which was fed by the granite gneiss of numerous area quarries, including Arabia Mountain. Remnants of this industry can be seen throughout the Heritage Area in the form of quarry office ruins, rock ledges, and drill holes on the rock. Much of the surrounding land was used for small-scale farming. The remains of the agricultural landscape are still visible in the National Heritage Area, including at the Lyon Farm, Vaughters Farm, and Parker House. Small settlements developed along crossroads, the South River (Upper Ocmulgee River), and the railroad, such as the Klondike National Historic District, Flat Rock community, and downtown Lithonia. Prior to 1880, the stone was hand quarried, but starting in 1879 workers used drills, dynamite and air compressors to "raise a ledge" or sever a large block of stone from the mass. That allowed more control over the size of the stone, and large stones could be used for dimensional or building construction. The proximity to the railroad meant that the Tidal Grey could be easily transported across the country. In 1949, the Lithonia district produced nearly 1.5 million tons of granite valued at the time at $3 million. Another advancement to the quarrying industry at Arabia Mountain was the discovery that adding granite grit to chicken feed helped with the birds' digestion. The Davidson family, which owned several quarries in the area, became the largest supplier of poultry grit in the world. They claimed that the sparkling particles of mica in the Stonemo grit attracted the eye and helped the chicken's gizzard break down food. The company was so successful in distributing their feed additive, a Time magazine article from 1941 reported the U.S. government allowed them to continue to operate during World War 2 in the name of national defense. Preservation In the 1970s, the Davidson family donated over 500 acres including Arabia Mountain and surrounding lands to DeKalb County as a nature preserve for local residents to enjoy. Since then, the Davidson-Arabia Mountain Nature Preserve has been expanded several times and now includes 2,550 acres, several granite outcrops and two lakes. On October 12, 2006, the mountain and Davidson-Arabia Mountain Nature Preserve were designated as nationally significant as a part of the Arabia Mountain National Heritage Area in recognition of its cultural, historical and natural features. The proximity to Atlanta, the second fastest-growing metropolitan area in the country during the 2000s, ==Geology==

The defining feature that gives the area its significance at the national level is its granite outcroppings, called monadnocks. These monadnocks are composed of a granitoid rock and are interspersed with islands of plant life. The Metro-Atlanta area has multiple monadnocks, including Stone Mountain, Arabia Mountain and Panola Mountain. The monadnocks were formed when erosion-resistant rock was exposed after softer rock eroded over time. The individual characteristics of the monadnock are determined by the individual processes that form the granite. For example, Arabia Mountain features a unique "swirl" pattern because the heat and pressure caused the rock to have a taffy-like consistency when it was cooling over 400 million years ago. Bands of different minerals folded and twisted, creating the "tidal swirl" pattern seen today . By contrast, Panola Mountain has a flakier rock with less compressive strength because of differences in cooling rates. Panola Mountain also has a darker colored rock and different mineral grains. Differences in mineral composition between Panola and Stone Mountains indicated different magma sources at the time of formation. ==Botany==

The seemingly barren landscape of Arabia Mountain is teeming with plant life specially adapted to live in the mountain's harsh environment. Arabia Mountain is one of five locations in the U.S. where black-spored quillwort (Isoetes melanospora) is found. It is one of 44 locations in the U.S. where little amphianthus (Amphianthus pusillus) is found. These are endangered species protected by Georgia and federal law. The largest and most important population of black-spored quillwort and one of the largest Amphianthus populations occur here. The U.S. Fish and Wildlife Service's five-year review of these species, completed in 2008, states "enforcement to protect sensitive areas needs improvement" in the Arabia Mountain area." Arabia Mountain is one of a small number of locations in the southeastern United States where Small's stonecrop (Sedum smallii, syn. Diamorpha smallii) thrives (this plant is not listed as an endangered species in Georgia or the U.S. but is in Tennessee). When granite and similar stone outcrops are exposed to erosion, over time, small depressions called solution pools form where weaker rock wears away faster than surrounding rock (often assisted by lichen). Over time, these depressions fill with sand washed down from higher locations, which accumulates a small amount of organic content from decaying dead leaves and other detritus, as well as rain water. Small's stonecrop then takes hold in these sandy hollows. It took thousands of years for plants and trees to grow in the granite outcroppings. The first plants on the mountains were lichens, which draw nutrients from dust and rainwater. Acids from these lichens and mosses gradually formed pits in the rock, called chemical erosion. This allowed shallow amounts of soil to accumulate, providing a place for more plant life to take root. This process is called primary succession as a succession of plants colonize the rock from lichen, to mosses, to diamorpha and larger plants, then gradually accumulating enough soil to support shrubs and trees. Not only does plant matter such as moss erode the rock and help to build soil levels in the pits, but the stone is also weathered by non-chemical factors. Wind, freeze-thaw cycles, and even lightning strikes cause the rock to fragment and break down. Cracks can form, giving another foothold to plant life, and the rock is broken into particles that add to the shallow soil. With the variety of ecosystems within the heritage area, the "edge effect" allows for greater biodiversity where two or more ecosystems intersect. For example, where the rock outcroppings border forests, the shallow soil retains more moisture from runoff and can support the species of both the rock outcropping and the forest. ==Gallery==

File:Arabia Mountain cairn.JPG| File:Arabia Mountain.JPG|Arabia Mountain File:Pair of endemic beetles - Collops georgianus.jpg|Collops georgianus on Arabia Mountain (endemic to such outcrops in Georgia) File:Diamorpha smallii.jpg| File:Colony of Black-spored Quillwort.jpg| File:Closeup of Black-spored Quillwort (Isoetes melanospora).jpg| ==References==