Square Rock, Norton Sound

Square Rock, Norton Sound

by | Mar 16, 2022

Square Rock is a marble pillar formed by an eroding sea stack situated about 200 feet (60 m) offshore from the eastern end of Bluff Cliffs on the south coast of the Seward Peninsula in Norton Sound, about 50 miles (80 km) east of Nome and 18 miles (29 km) west of Golovin, Alaska. The local name was first reported in about 1940 on charts by the U.S. Coast and Geodetic Survey. Much of the Seward Peninsula is underlain by Early Paleozoic and possibly older limestone and slate. These rocks are flanked on the southeast by marble and schist of about the same age. Marble is a rock resulting from the metamorphism of sedimentary carbonate rocks, most commonly limestone or dolomite. Metamorphism causes variable recrystallization of the original carbonate mineral grains. The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals. Pure white marble is the result of the metamorphism of very pure limestone or dolomite. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, iron oxides, or chert which were originally present as grains or layers in the limestone. Green coloration is often due to serpentine resulting from originally magnesium-rich limestone or dolomite with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism. In general, the highlands and coastal bluffs are underlain by marble which supports little or no vegetation, and the lowlands are underlain by schist which is tundra-covered and has little or no outcrop. The marble, which crops out along much of the coast, dips northward under the schist. The gold-producing creeks on the south coast of the Seward Peninsula drain alluvial basins underlain by both marble and schist. The Bluff Cliffs represent the most common rock in the area which is a pale-gray to white coarse crystalline marble forming rounded ridges that may extend for several miles. The gray marble is dominant and reaches thicknesses of 0.5-1.5 miles (1-2 km). Gold lodes and placers in the Bluff area are located near a marble-schist contact zone.

Evidence of the earliest humans to inhabit Norton Sound was found at an ancient settlement called Iyatayet at Cape Denbigh about 64 miles (103 km) east-southeast of the Bluff Cliffs. They lived there during a warm period in Alaska more than 8,000 years ago and perhaps more than 12,000 years ago and are called the Paleo-Arctic Tradition. From 7,000 years ago until 4,500 years ago, the Northern Archaic Tradition replaced the Paleoarctic Tradition throughout the interior and coastal mainland Alaska, and the Yukon Territory of Canada. The signature technology of the Northern Archaic culture included large chipped stone side-notched points. From 4,000 to 3,000 years ago, the Arctic Small Tool Tradition developed and is identified by small finely chipped stone tools including end blades, sideblades, microblades, knives, and adzes with polished edges. The Norton Tradition replaced the Alaska Small Tool Tradition in western Alaska about 3,000-1,000 years ago. The Norton people used flake-stone tools like their predecessors, but they were more marine-oriented and brought new technologies such as oil-burning lamps and clay vessels into use. Norton people used both marine and land resources as part of their subsistence strategy. They hunted caribou and smaller mammals, as well as larger sea mammals, and fished for salmon. Their settlements were occupied fairly permanently, as is evidenced by village sites that contain substantial dwellings. During summer months, small camps may have been used as temporary hunting and fishing locations, but the main dwelling place was maintained and returned to at the end of the hunting season. In about 700 BC, the Norton inhabitants of Saint Lawrence and other Bering Strait islands developed an even more specialized culture, based entirely on the ocean, called the Thule Tradition that lasted from 1,000-200 years ago and are the ancestors of the present-day Iñupiat. They developed in coastal Alaska and expanded eastward across northern Canada, reaching Greenland by the 13th century. They are known for using slate knives, umiaks, seal-skin floats, and toggling harpoons. The Thule subsisted primarily on marine animals, especially large sea mammals such as walruses and whales. Intensified contacts with Europeans began in the 18th century, followed by Americans subsequent to the Alaska Purchase in 1867. Placer gold deposits may have been discovered on the Seward Peninsula as early as 1865-66 by a party surveying a route for the Western Union Telegraph Expedition that planned to connect Europe and America by way of Siberia and the Bering Strait. This was followed by major gold discoveries near Nome in 1899, and during the winter of 1899-1900, a phenomenally rich gold beach at the mouth of Daniels Creek and the western end of Bluff Cliffs was discovered and 70,000-75,000 ounces of placer gold was recovered in the area by 1920. The mining camp of Bluff was located at the mouth of Daniels Creek and was abandoned around 1919, probably as a result of the influenza epidemic.

The Bluff Cliffs extend east from the mouth of Daniels Creek for about 4 miles (6 km) along the coast and support one of the largest seabird colonies in Norton Sound. The seabird colony at Bluff Cliffs has reputedly been studied more continuously than any other in Alaska. Studies were started in 1975, and monitoring has been conducted in most years since then. The Bluff Cliff colonies are by far the largest congregation of cliff-nesting seabirds on the mainland coast of western Alaska outside of Bristol Bay about 370 miles (600 km) to the south. The site includes 5 closely located colonies with common feeding areas at sea. The Bluff Cliffs colony is the largest, with around 125,000 nesting seabirds. The Square Rock colony is next in size, while the other three are considerably smaller. Common murres make up most of the population, along with a small number of scattered thick-billed murres, with an estimated number on Square Rock and the adjacent mainland cliffs of 10,000 individuals. Black-legged kittiwakes are also present in significant numbers. Common murres breed in colonies with high densities and may be in bodily contact with their neighbors. They make no nest, and their single egg is incubated on a bare rock ledge on a cliff face. Eggs hatch after about 30 days of incubation. About 20 days after hatching the chick leaves its nesting ledge, and still unable to fly, glides for some distance over water with fluttering wings. Chicks are capable of diving as soon as they hit the water. The common murre can venture far from its breeding grounds to forage with distances of 60 miles (100 km) observed. The common murre is a pursuit-diver that forages for food by swimming underwater using its wings for propulsion mainly feeding on small schooling forage fish such as polar cod, capelin, sand lances, sprats, and sand eels. The global population of common murres is large, perhaps 7.3 million breeding pairs, but in 2016 a massive die-off of the birds occurred in the northeast Pacific. Read more here and here. Explore more of Square Rock and the Bluff Cliffs here:

About the background graphic

This ‘warming stripe’ graphic is a visual representation of the change in global temperature from 1850 (top) to 2021 (bottom). Each stripe represents the average global temperature for one year. The average temperature from 1971-2000 is set as the boundary between blue and red. The color scale goes from -0.7°C to +0.7°C. The data are from the UK Met Office HadCRUT4.6 dataset. 

Credit: Professor Ed Hawkins (University of Reading). Click here for more information about the #warmingstripes.

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