Primary coasts

All landforms, whether they are coasts or mountains, are formed and changed by geological processes. Coastlines can be divided into two large groups, based on whether their traits were primarily defined by land processes or by sea processes. Those sculpted by land processes are called primary coasts, and the ones that have been shaped by the ocean are called secondary coasts. 

The types of land processes that shape the appearance of a primary coast include precipitation (rain, snow, sleet, and hail), erosion, and deposition of sediments by wind and water. On a geologic time scale, primary coasts are fairly young and have been in very much the same condition since after the last ice age, 6,500 years ago. In this short stretch of geologic time, the ocean has not had time to alter them. 

The soil on a primary coast was once a part of the land. In some cases, the soil was deposited on the coast by wind or... 

Primary coasts are also formed by shifts in the Earth s crust. When plates of the crust change positions, they can create large tears or splits called faults. If a fault forms at the coast, seawater rushes into it and creates a fault bay. The Gulf of California, also called the Sea of Cortes, lies between Baja California and mainland Mexico. At one time, Baja California was part of the North American continent. When the crustal plates slid horizontally past each other, a bit of land, the area now known as Baja California, was ripped away from the continent. 

Secondary coasts are areas that have been changed by marine processes. Like primary coasts, they were originally formed by processes on land, but they have been around longer than primary coasts, long enough for their appearance to be influenced by action of the sea. 

Infrared. The use of infrared for oil fingerprinting is well documented (32,33,34,35). The technique has a well-demonstrated capability and is one of the four primary Coast Guard methods (18) that is in operational use by COIL. In addition, it has been tested in the field for over a year in Philadelphia and will shortly begin testing in San Francisco, California, and New York, using relatively inexpensive dual-beam grating instruments. 

Salt-Dome Sulfur Deposits. The sulfur deposits associated with salt domes in the Gulf Coast regions of the southern United States and Mexico have historically been the primary sources of U.S. sulfur. These remain an important segment of both U.S. and world sulfur supply. Although the reserves are finite, many are large and voluntary productive capacity ensures the importance of these sources for some time to come. In 1994, the output from the salt domes in the U.S. was about 2.09 million metric tons (21). 

Oligomerization of Ethylene. 1-Butene is a small by-product in the production of linear alpha-olefins by oligomerisation of ethylene. Linear alpha-olefins have one double bond at the terminal position and comprise the homologous series of compounds with carbon atoms between 4 and 19. The primary use of alpha-olefins is in the detergent industry. About 245,000 t/yr of 1-butene was produced for chemical use in the Gulf Coast of the United States in 1988 (72). 

Diamonds were first discovered in ancient times in India and Borneo and later in Brazil in 1670 in alluvial deposits where water had sorted minerals on the basis of density and toughness. This type of tumbling often concentrates the better quality crystals such as those found in the ocean off the west coast of Africa. Exploration can be done by stream panning or drilling in conjunction with a search for the heavy mineral assemblages that accompany diamond. Alluvial deposits account for about 40% of the diamond found in primary sources. 

Several countries supply monazite concentrates for the world market. Extensive deposits along the coast of western AustraUa are worked for ilmenite and are the primary source of world monazite. Other regions of AustraUa, along with India and Brazil, also supply the mineral. Because monazite contains thorium [7440-29-1], India and Brazil have embargoed its export for many years. In the United States, commerce in the mineral is regulated by the Nuclear Regulatory Commission. 

Cobalt is one of twenty-seven known elements essential to humans (28) (see Mineral NUTRIENTS). It is an integral part of the cyanocobalamin [68-19-9] molecule, ie, vitamin B 2> only documented biochemically active cobalt component in humans (29,30) (see Vitamins, VITAMIN Vitamin B 2 is not synthesized by animals or higher plants, rather the primary source is bacterial flora in the digestive system of sheep and cattle (8). Except for humans, nonmminants do not appear to requite cobalt. Humans have between 2 and 5 mg of vitamin B22, and deficiency results in the development of pernicious anemia. The wasting disease in sheep and cattle is known as bush sickness in New Zealand, salt sickness in Florida, pine sickness in Scotland, and coast disease in AustraUa. These are essentially the same symptomatically, and are caused by cobalt deficiency. Symptoms include initial lack of appetite followed by scaliness of skin, lack of coordination, loss of flesh, pale mucous membranes, and retarded growth. The total laboratory synthesis of vitamin B 2 was completed in 65—70 steps over a period of eleven years (31). The complex stmcture was reported by Dorothy Crowfoot-Hodgkin in 1961 (32) for which she was awarded a Nobel prize in 1964. 

Major sources of lead in Atlantic coast streams included wastes from metal-finishing industries, brass manufacturing, lead alkyl production, primary and secondary lead smelting, coal combustion, and manufacture of lead oxide. 

ILLUSTRATION 15 Along the Pacific coast of North America, barnacles and mussels are the ochre starfish s primary prey. 

Minnesota, Iowa, and Illinois (9). As indicated by its common name, the hop-vine borer had been found in close association with hop (Humulus lupulus) plants. Wild hops, found from the east coast of the U.S. to the Rocky Mountains, presumably served as the primary host for the Insect in North America (10) for the last 100-150 years or longer. 

In this paper we present results which reconcile the widely different results just discussed ranging from a carbon aerosol dominated by secondary organic material on the one hand to a carbon aerosol composed largely of primary carbon compounds on the other. We have employed an approach which uses lead or elemental carbon as a tracer for primary emissions and combines several analysis techniques to reexamine the published ACHEX data. We also present a new data set from St. Louis which is analyzed in a similar manner to contrast the aerosol in a midwestern city with that on the California coast. 

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