Niggerhead

We were sailing swiftly along on a calm and glassy sea, past beautiful headlands and bits of scenery clothed with vivid and luxuriant green down to the water's edge; past glistening coral islands, on whose outer edges pale green billows broke on the white sandy beaches, boiling and seething as they dashed against a row of ugly "nigger heads," as the rocks were called, dotted here and there.

Landward is the almost unbroken wall of submerged reefs where the big niggerhead corals send their solid bulks up to within a fathom or two of the surface.

These plants fill the interstices between the grasses and tiny shrubs that make the outer, fuller form of the niggerhead.

Responsible in large part for the difficulties of movement to which the geologists referred were tussocks, still known as “niggerheads” in the 1930s. The “niggerhead,” according to Bob Marshall, “among the gifts of nature, ranks as the most cursed.[…]”

Much of the land is tundra, a mass of spongy, waterlogged clumps of sphagnum moss called tussock, muskeg, hummock, or in the vernacular of old-time Alaskans “niggerheads.”

From the air, the bright green grassy floor of the tundra looks as smooth as a golf course fairway, but a closer inspection reveals peaty tussocks of crabgrass called niggerheads spaced just far enough apart for a foot to twist clumsily between. Walking on the frost-formed niggerheads is very much akin to walking across a gymnasium floor covered by thousands of glued-in-place softballs.

This sloshing was compounded by the fact we were unable to keep in step with each other due to the many and various sized niggerheads (hard tussocks in tundra) that would attempt to roll from under us as if one was stepping on balls ranging in size from softballs to basketballs, with each step if unable (most of the time we could not) to avoid.

The boys picked up field-stones and built a great, splendid fireplace and chimney at one end of the shop. The work came out so well that I said: "Boys, here is a great scheme—these hardheads are splendid building-material." So we advertised we would pay a dollar a load for niggerheads. The farmers began to haul stones; and at last they had hauled eighteen hundred loads.

The presence of "niggerheads" is of rather common occurrence in the northern area. These are nodule-like bodies of coal, varying from a few inches to a few feet in diameter, irregularly disseminated in the beds of normal coal. The "niggerheads" are harder than ordinary coal and have a smooth, locally slickensided, lustrous outer surface. The interior is composed of alternating bands of bright and dull coal like the surrounding bed. "Niggerheads" evidently are due to physical strains, but their origin is obscure.

Foreign materials in the bed. Aside from the ash which may be scattered all through the coal, and bands of clay or other parting rock, the coal frequently contains concretionary and other bodies called "coal balls," "coal apples," and "sulphur balls" ("hardheads" or "niggerheads"). Coal apples and balls consist mainly of calcium carbonate, magnesium carbonate, iron carbonate, and iron oxide, with some clay, shale, or sand. The sulphur balls consist of pyrite or marcasite (FeS₂) mixed with clay or sand. Some of the latter, when broken, show the bright, brass-yellow color, "fool's gold," characteristic of pyrite. More commonly they are heavy, but when broken show only a dull black or dark gray surface, sometimes with a suspicion of brassy sparkle. These pyrite or marcasite concretions may be small or large, abundant or widely scattered. Most commonly when present they are found in some definite position, as near the top of the bed of coal. Where the coal is overlain by marine shales there may be so many of these sulphur balls in the roof as to constitute nearly the entire roof material. Where the concretionary material is calcareous, making "coal balls," it frequently contains pieces of plants often well preserved, and it is noted that these plants may be of different kinds from those found in the coal bed, suggesting that they were transported from a distance. In a few places the coal contains stumps of trees that originally grew in the under clay of the coal and having died were in part buried by the accumulation of swamp matter.