Bitumen sources

No complete surveys of either bitumen sources or ancient townsites exist. Geographical coordinates of the sources of all samples described in the present work are given in Table I along with the names of the investigators who recovered them and from whom they were obtained. Of the 14 archaeological sites and 8 locations for possible source materials listed, asphalts from 7 had been studied previously, and 17 were included in the present investigation. 

Bitumen Sources. Analyses of possible source materials are given in Table VIII. The seepages of Hit and such bitumen lakes as Abu Gir are the traditional sources for asphalts of the cities of lower Mesopotamia. Despite repeated attempts, samples could not be obtained for analysis. 

The bitumen layer from the experiment at 80°C and 15 min mixing time on top of the tar sand and from the rest of the sand were harvested and extracted with THE Vanadium contents were also obtained from these two bitumen sources and from the tar sand source. For the tar sand, bitumen was also extracted by repeated washings of THE followed by drying of the THE from the wash fluids. One gram of... 

Distinctions between tar sands bitumens and heavy oils are based largely on differences in viscosities. The bitumen in oil sand has a specific gravity of less than 0.986 g/mL (12°API), and thus oil sands may be regarded as a source of extremely heavy cmde oil. Whereas heavy oils might be produced by the same techniques used for the lighter cmde oils, the bitumens in tar sands are too viscous for these techniques. Consequently these oil-bearing stones have to be mined and specially processed to recover contained hydrocarbon. 

Bituminous This term is used for products obtained from both petroleum and coal tar sources but the petroleum products are the more widely used. These materials are very resistant to moisture and tolerant to poor surface preparation. They are only available as black, dark brown or aluminum pigmented. The last has reasonable outdoor durability but, without the aluminum, the film will crack and craze under the influence of sunlight. Normally they cannot be over-coated with any other type of paint, because not only will harder materials used for over-coating tend to crack or craze but there is also a possibility that the bitumen will bleed through subsequent coats. The best use is as a cheap waterproofing for items buried or out of direct sunlight. 

Boeda et al. (1996) identified bitumen on a flint scraper and a Levallois flake, discovered in Mousterian levels (about 40 000 BP) at the site of Umm el Tlel in Syria. The occurrence of polyaromatic hydrocarbons such as fluoranthene, pyrene, phenanthrenes and chrysenes suggested that the raw bitumen had been subjected to high temperature. The distribution of the sterane and terpane biomarkers in the bitumen did not correspond to the well-known bitumen occurrences in these areas. In other studies of bitumen associated with a wide variety of artefacts of later date, especially from the 6th Millennium BC onwards, molecular and isotopic methods have proved successful in recognizing different sources of bitumen enabling trade routes to be determined through time (Connan et al., 1992 Connan and Deschesne, 1996 Connan, 1999 Harrell and Lewan, 2002). 

Harrell, J.A. and Lewan, M.D. (2002). Sources of mummy bitumen in ancient Egypt and Palestine. Archaeometry 44 285-293. 

Connan, J., Lombard, P., Killick, R., et al. (1998). The archaeological bitumens of Bahrain from the Early Dilmun period (c. 2200 BC) to the sixteenth century AD a problem of sources and trade. Arabian Archaeology and Epigraphy 9 141-181. 

Despite the considerable growth of the Canadian oil sands industry in recent years, there are still several difficulties that could impede the future development of this industry for instance, the heavy reliance on natural gas and water, which are necessary for both the extraction of bitumen from oil sands and its upgrading to synthetic oil, as well as the associated high emissions of C02. For nearly a century, the oil shale in the western United States has been considered a possible substitute source for conventional crude oil. If a technology can be developed to recover oil... 

Asphalt (referred to as bitumen in some parts of the world) is produced from the distillation residuum. In addition to road asphalt, a variety of asphalt grades for roofing and waterproofing are also produced. Asphalt has complex chemical and physical compositions, which usually vary with the source of the crude oil, and it is produced to certain standards of hardness or softness in controlled vacuum distillation processes (Barth, 1962 Bland and Davidson, 1967 Speight, 1999, and references cited therein Speight and Ozum, 2002). 

Bituminous containing bitumen or constituting the source of bitumen. 

Algal sources are ice algae, diatoms, cyanobacteria, dinoflagellates, and picoplankton petroleum sources include eroded bitumens, oil seeps, etc. 

Source Identified in Kuwait and South Louisiana crude oils at concentrations of 6.9 and 17.5 ppm, respectively (Pancirov and Brown, 1975). Also present in high octane gasoline (6.7 mg/kg), bitumen (1.64-5.14 ppm), gasoline exhaust (27-318 pg/m ), cigarette smoke (60 pg/1,000 cigarettes), and South Louisiana crude oil (17.5 ppm) (quoted, Verschueren, 1983). Also detected in fresh motor oil (56 mg/L), used motor oil (10.17 mg/L) (Pasquini and Monarca, 1093). 

Schimmelmann A, Lewan MD, Wintsch RP (1999) D/H ratios of kerogen, bitumen, oil and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS and III. Geochim Cosmochim Acta 63 3751-3766... 

The characterization of a novel series of biomarkers is illustrated with the g 7 2-dialkylalkanes in bitumen from a hydrothermal system on the Mid-Atlantic Ridge. The total bitumen consists of hydrocarbons, a major UCM (unresolved complex mixture of branched and cyclic compounds) and mature biomarkers (e.g. hopanes) (Fig. 13a). The bitumen contains a series of cyclopentylalkanes Cfi 2n) that range from n = 14 to 34, with only even-chained pseudohomologs and a concentration maximum (Cmax) at n = 18. Their source is biogenic, based on the presence of only even-carbon number homologs, but the precursors are unknown. 

Occupational exposure to ethylbenzene may occur by inhalation during its production and use. Most occupational exposures are related to technical grades of mixed xylenes used as solvents in various paints and coatings, inks, insecticides and in rubber and plastic production, as well as from the production and handling of gasoline and bitumen. Ethylbenzene from these sources as well as from vehicle emissions is ubiquitous at Xg/m levels in ambient air. It is a component of tobacco... 

Bitumen describes a black or dark brown masticlike material that is thermoplastic in nature and softens upon heating. The sources of bitumen are petroleum or coal deposits. The natural product is commonly called gilsonite or pitch, a mineral formed by an old weathered petroleum flow at the surface of the earth that has left behind the larger molecules from the petroleum. A principal source in the past has been Lake Trinidad, a 445,000 m2 deposit on the island of Trinidad. Bitumen from petroleum or crude oil is called asphalt (qv). It is the material left behind after all the valuable compounds, eg, gasolines, have been distilled out of the cmde oil. The amount and quality of asphalt is dependent on the source of the crude oil used in the refining process. Some cmde oils have a higher content of asphaltic bitumen left after the distillation process. Bitumen from coal is coal-tar pitch. It remains after the valuable coal oils and tars have been distilled out of the coal tars produced by distractive distillation. Most industrial applications for bitumen products use asphalt or coal-tar pitch because the supply is more uniform and plentiful. 

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