Ulúa-Style Marble Vase Project: Dissemination of Results

Chemical Signatures of Sources and Vases

The materials science component of this study included two goals. First, possible sources of marble were located and sampled (Luke et al. 2000; Luke and Tykot 2002, 2001, m.s.). The second component was to sample vases in hopes that their signatures would provide data on the number of possible sources and may overlap with sampled sources and, thus, indicate potential procurement areas. For the vases and the sources stable isotope analyses of the ratios of carbon 13 and oxygen 18 were used, as these ratios have proven to be effective for sourcing marble in the Mediterranean (see papers in Herz and Waelkens 1988; True and Podany 1990; Waelkens et al. 1992; Maniatis et al. 1995; Herrmann et al. 2002; Herz 1990, 1992; Pike 2000; Tykot, Hermann et al. 2001; Tykot, R.H., R. Newman et al. 1998; van der Merwe, Hermann et al. 1995). Petrographic analyses of sources helped determine which sources were true marble and their respective geologic age.

The geological survey concentrated on the low hills on the valley floor and the surrounding mountain ranges. Samples were taken from sixty-nine Ulúa-style marble vases from museum and excavation collections in the United States, Italy, Honduras, and Guatemala; results were inconclusive for one vase. All but one stylistic group is represented in the sampled corpus. At the time of sampling, vases with a single bird handle were not included in the study as none were held by museums or stored in excavation depots (Luke 2002b). Based on my research one-hundred thirty-six vases and fragments are located in museum and excavation collections. Chemical results presented in this study represent approximately 50% of this known corpus. Future analyses will include an additional thirty vases from museum and excavation collections making the final sample size approximately 70% of this corpus.

The petrographic results and consultations with Marmoles de Honduras confirm that there are three marble sources in the valley (Luke et al. 2000). A number of limestone sources were located and used for the data presented in the dissertation. Our understanding of the chemical signature of limestone bedrock of an exhausted marble source was that it would be the same as marble once available at the quarry (Luke and Tykot 2002). Based on recent consultations with colleagues, this may not be true and, hence, this study must rely only on the sources that we have evidence for marble. Thus, the original data set has been reduced to only three quarries (Luke and Tykot, m.s.).

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Stable isotope analyses of sixty-eight Ulúa-style marble vases indicate that vases do have similar isotopic ratios. The majority of vases sampled, fifty-eight vases (85% of the sample size), fall into a very tight group, shown as Cluster A in Figure 3, above. Eight vases make-up Cluster B (8.5% of the sample size). Two sampled fragments fall outside of these two cluster groups, tentatively called Cluster C.  The concentration of fifty-eight vases in Cluster A suggests that a single marble source was preferred. The two other clusters may indicate a second location from the same source ²   or two additional sources.

All broad stylistic groups (Groups 1-5) were included in this sample and are included in both Cluster A and Cluster B; the outlying Cluster C results are from two small fragments from Altun Ha in Belize. Results from the vases demonstrate that there was most likely one primary source, those vases part of Cluster A.  Clusters B and C could represent outliers from the same source used to produce vases from Cluster A or they represent secondary sources.

Petrographic results confirm marble at three sources. The stable isotope results of these sources can be compared with the vase results (Luke and Tykot m.s.). Quarry 2 overlaps with both Cluster A and Cluster B; Quarry 3/4 overlaps with Cluster B; Quarry 5 overlaps with Cluster A.

These results suggest two different procurement scenarios. First, Quarry 5, the closest source to Travesía and located near a local obsidian source, may have been the preferred source with two secondary sources. Quarry 5 has a commanding view of the entire central valley, particularly the Travesía area. Quarry 2 is located along a prominent southern exchange route to El Cajon, Olancho, and Lower Central America beyond. Its large cliffs may have acted as a beacon attracting attention to the source. Similarly Quarry 3/4 is located along the northern route, again with prominent white cliffs that may have held special significance in procurement processes.

The second alternative is that Quarry 2 was the primary source and Quarry 3/4 was a secondary source; Quarry 5 may or may not have been used. The large isotopic field of Quarry 2 overlaps with all but the fragments from Altun Ha, strongly arguing for this as the main source. Under this scenario, Cluster B most likely represents a second procurement area in Quarry 2 and the samples from Altun Ha point to the northern source, Quarry 3/4.

Endnote

2. Pike’s (2000) research on Pentelic marble very clearly demonstrates that specific areas of this quarry have homogenous signatures, while the entire signature of a given quarry may be very broad. Artifacts have been attributed to specific zones in the quarry, many with ancient quarry marks. Hence, it is likely that areas in Quarry 2 may have very specific signatures within the broad isotopic field.

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