PETROGRAPHIC ANALYSIS OF POTTERY FROM THE WHITE MARL ARCHAEOLOGICAL SITE, ST. CATHERINE PARISH, JAMAICA, WEST INDIES

Petrographic analysis was conducted on a series of prehistoric ceramic pottery sherds from the White Marl archaeological site in Jamaica, as well as raw clay and sand samples from the Rio Cobre valley within the site. Given the size and structural complexity of White Marl, it likely served as a major social, political, and economic hub within Jamaica and possibly across islands. To address the origin of materials from which White Marl pottery was produced, a point count was conducted on ten pottery sherds that are representative of the range of ceramic vessel forms and functions. On each thin section, 300 to 500 points were examined in order to gain a quantitative percentage of the mineralogical composition present within thin section. The thin sections of pottery sherds display angular mineral grains of varying sizes within a dark brown to orange clay matrix. Pore spaces within the clay matrix are aligned in the same direction, indicating that they have a preferred orientation. The mineralogy of these sherds is dominated by clay (58.0-64.8%), quartz (21.1-32.3%), and feldspars (2.4-6.7%), with minor amounts of opaque minerals (0.8-4.6%), muscovite (0.2-2.1%), and amphiboles (0.0-1.6%). Well weathered rock fragments also commonly occur within the matrix (0.9-6.6%). Quartz grains display undulose extinction which is indicative of deformation, and plagioclase feldspar grains display systematic zonation from the core outwards, possibly from volcanic origin. The raw clay deposits from the Rio Cobre are orange in color, which appears similar to the matrix of some of the pottery sherds observed. Quartz, feldspars, and opaque grains are present in the raw clay slides, and are very small in diameter in comparison to the grain size of pottery sherds. A preliminary point count of Rio Cobre riverbed sand samples show that they are dominated by quartz (50.4%), clay (19.3%), feldspars (8.7%), opaques (7.6%), and amphiboles (6.8%), with minor amounts of muscovite (1.9%) and rock fragments (1.1%). This ongoing petrographic analysis will allow us to model the origin of this clay and see how it evolved into the material used in Caribbean ceramics. These findings show that the material used in ceramics is homogeneous across samples, suggesting that a standard recipe was followed in the production of the full range of vessel forms.