Ancient quarries are intriguing archaeological sites, but their detailed recording is complex. This paper presents a cost-effective approach to mapping of the Roman quarry site of Pitaranha (Portugal-Spain). First, aerial photographs were acquired using a radio-controlled digital reflex camera attached to a Helikite, which allowed the acquisition of the necessary low-altitude aerial footage in the very unstable wind conditions above the quarry. Using computer vision algorithms, the resulting set of photographs was semi-automatically transformed into a Digital Surface Model (DSM) and a corresponding orthophotograph. Besides focusing on the acquisition and processing method, this paper evaluates the accuracy of the generated products. The orthophotograph proved to be satisfactorily accurate for 1:200 hard-copy mapping.

a b s t r a c tThis paper reports the results of an archaeometric study of the marble from the Estremoz Anticline, Portugal. Thirty-four samples from eleven different locations were analysed petrographically. In addition, ten samples were selected for trace element and strontium isotopic analysis. The sampling was aimed at obtaining material from known ancient quarries and at establishing the overall petrographic and geochemical variation of the marble from the Estremoz Anticline. The main type of marble in Estremoz is a white(-veined), calcitic marble with an average maximum grain size between 0.81 and 3.50 mm. In addition, a workflow is proposed for distinguishing Estremoz from non-Estremoz marble. For this, the Estremoz marble signature is compared to that of other known Roman marbles of the Iberian Peninsula (Viana do Alentejo, Almeria group, Malaga group, and Almadén de la Plata), as well as to that of the principal classical marbles from the Mediterranean (Carrara, Paros, Naxos, Pentelikon, Hymettos, Dokimeion, Thasos, Aphrodisias and Proconnesos).

In this paper, the impact of spatial sample density and three-dimensional migration processing on the interpretation of archaeological ground-penetrating radar (GPR) data is assessed. First, the question of how to determine the sample interval required to take full advantage of the spatial resolution capabilities of GPR without oversampling is addressed. To this end, we transform a test profile into the frequency-wavenumber (f-k) domain and estimate the required sample interval from the wavenumber values. For the presented data set, collected at the Roman town Ammaia (Portugal), this resulted in a transect spacing approximately three times the distance prescribed by the λ min /4 criterion (where λ min is the minimum observed wavelength). Second, the effect of three-dimensional migration is assessed. The data set, sampled as prescribed by the analysis of the f-k plot, is migrated with two-and three-dimensional phase-shift algorithms, and the migrated results are compared with non-migrated data. It is shown that certain subtle features are better resolved by three-dimensional migration. Third, it is investigated whether three-dimensional migration following the application of an interpolation algorithm such as Delaunay triangulation or interpolation based on τ-p transform, can further relax spatial sampling requirements. For the GPR data shown in this article, it is demonstrated that interpolation and three-dimensional migration of slightly aliased data, collected with a transect spacing equal to five times the outcome of the λ min /4 criterion, still allow a faithful reconstruction of the original, non-aliased time-slices. Figure 5. Energy time-slices from between 31 and 32 ns, showing details from areas 1A and 1B, surveyed with a 0.05 m × 0.05 m grid spacing in east west and north south directions, respectively: (a and b) data after three-dimensional phase-shift migration; (c and d) data after two-dimensional phase-shift migration in in-line direction; (e and f) Unmigrated data. The large arrows show the direction of the survey lines. The numbers are explained in the text.

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Samples from 22 white crystalline and one greco scritto‐like marble artefacts (first–third centuries ce) from Roman Sentinum (Sassoferrato, Italy) were analysed to determine their provenance by thin‐section microscopy, X‐ray diffraction and stable isotope ratio analysis (δ18O and δ13C). Polychrome marbles were provenanced through macroscopic examination. Results show that relief sculpture and statuary were carved in white marble from Carrara, Paros, Thasos and Naxos. Architectural white marbles were identified as Proconnesian for veneer, and Proconnesian, Parian, Dokimeion and Thasian for capitals and pediments. Polychrome lithotypes include foremost africano, breccia di Sciro, cipollino verde, giallo antico, bardiglio and greco scritto (from Ephesos‐Hasançavuslar).