Coal geochemistry in the service of archaeology

摘要

In the recent Journal article Coal microscopy in the service of archaeology, A.H.V. Smith (2005) describes several interesting and unusual applications of coal microscopy to a broad range of archaeological issues. In the last example provided (p. 58), Dr. Smith notes that reflectance was determined on "a small piece of coal claimed to have been recovered from the wreck of R.M.S. Titanic." Dr. Smith notes that, in order for the Titanic to sail on schedule during a coal miners' strike, the coal may have been scavenged from six other ships sitting in port. He concludes that "It seems unlikely that the origin of the coals from the different sources will ever be known or whether the coals were mixed or segregated in the ship's bunkers." Dr. Smith and the readers of this Journal may be interested to know that a more extensive study of the coal from the Titanic was carried out recently by Palmer et al. (2002, 2003). These authors examined the physical, chemical, and palynological characteristics of 20 pieces of coal recovered from the wreck of the Titanic. The fixed carbon and volatile matter indicated that all of the coal samples were bituminous in rank, with an almost equal distribution of low volatile, medium volatile, and high volatile samples. These data indicate that the coal on board the Titanic came from at least three different sources. Major, minor, and trace element concentrations were determined on the individual pieces of coal. The results, especially the Cr/Ni ratio are more consistent with coals from the U.K. than from the U.S. This is also consistent with results from spore assemblages recovered from two samples. Rare-earth-element distribution patterns indicate that the Titanic coal samples may have come from as many as five sources. Palmer et al. (2002. 2003) concluded that the U.K. was the likely source of most of the coal particles recovered from the Titanic; however, some of the coal may have come from the U.S.