The role of topography

Before getting into why this shift may have occurred, it is worth considering other features of the local landscape. Among the most obvious factors is the region's topographic relief. For each of the eight sites explored by MHS, elevation and slope

measurements652 _{were recorded within an area corresponding to the minimum}

rectangle bounding all Topographic Units surveyed at that site. Minimum, maximum, and average values for both of these characteristics appear in Tables 15 and 16, respectively, in Appendix 1. (Standard deviation is also provided.)

As a predictor of Roman-period activity, synchronically-speaking, elevation seems pretty weak. The evidence for a correlation is not precisely absent, but it is relatively inconsistent: more so, in fact, than in the case of distance from the coast. The first– and third most productive sites—San Leonardo and Piscitello, respectively—are also the first– and third lowest.653 _{But the sites at Genna and Ditta} Barbagallo, which constitute the second– and fourth most productive sites, are

among the highest.654 _{And, conversely, two of the lowest—Borso and}

Marcanzotta655_{—seem hardly to have been occupied, at least during the period of} interest to this thesis.

Viewed diachronically, these data make a little more sense. As in the case considered in Section III.3.1, it is possible to adumbrate a (partial, and by no means hegemonic) trend. To judge by the numbers, the renovation of activity at Casa Abbadessa and Timpone Granatello, and the coetaneous cessation of the same at Ditta Barbagallo, reflect a shift to higher places. Insofar, however, as they also

represent a shift inland, per the results just mentioned, it is difficult to assess the significance ofelevation, per se. As described elsewhere in this thesis,656_{the hinterland} of Marsala is a landscape in which, grosso modo, altitude increases with distance from the coast. (In the uppermost third of the project survey universe, where all our sites are located, Marcanzotta is the only exception to this rule.) Under the 652. As calculated on the basis of the project DEM (see Chapter 3, n. 91). As a proxy for "topography", the consideration of these two characteristics is obviously less than comprehensive. Among other things, it fails to account for aspect. But the centrality of these two attributes is such that they are nevertheless a useful shorthand.

653. Both in respect of their maximum (SL: 16 m asl; PI: 47 m asl) and average (SL: 7.6 m asl; PI: 42.7 m asl) elevation.

654. Genna: max. elevation, 142 m asl; average, 130.2 m asl. Ditta Barbagallo: maximum, 106 m asl; average, 102.4 m asl.

655. Borso: max. elevation, 44 m asl; average, 34.6 m asl. Marcanzotta: max. elevation, 56 m asl; average, 48.4 m asl.

circumstances, it is difficult to gauge the degree of influence exercised by the former characteristic independent of the latter.

Where slope is concerned, meanwhile, we need not fear a similar sort of entanglement.657 _{Accurately assessing its influence, however, is not much less} fraught. Prima facie, there are more and better indications of a relationship between site chronology and –gradient. Three of the four best-attested Roman sites (Ditta Barbagallo, Piscitello, and San Leonardo) are characterized by relatively low maximum and average slopes. And if we focus on the latter measure, the fourth, Genna, is, too.658₎

Thesignificanceof this relationship, however, is less clear. First of all, it is very probably overdetermined, in no small part as a result of project methodology. Practically speaking, the difficulty of systematic (and maybe especially intensive

systematic) archaeological survey increases with steepness of slope. It is clear, in view of the areas designated for survey, that the project leaders had this fact in mind. Four of the eight sites (Borso, Marcanzotta, Piscitello, and San Leonardo) explored by MHS are not simply flat; they are surrounded by open, and similarly flat, terrain. The others, meanwhile, are located near the edge of a plateau. But in no case does the area actually subjected to collection extend beyond the margins of that plateau.

Quite apart from such concerns, however—and presuming, arguendo, that they do not constitute too great a source of bias!—are questions of interpretation. As we have already noted, gentle slopes appear to be positively correlated with greater intensity of Roman activity, grosso modo. In one sense, this is an unsurprising, even banal, result. It is easy to build in flat landscapes, and buildings tend to encourage more permanent occupation. The occurrence of settlement in places of low average slope is less a feature of habitation in this region, I think, than of settlement tout court.

Interestingly, however, the correlation is stronger when we consider

maximum, as opposed to average, slope. Aside from at San Leonardo, where the highest recorded slope (8.4º) occurs on an incline facing northwest from the center of DU 1006, the highest measures of maximum slope were recorded at the inland plateau sites mentioned above. More specifically, they are located near enough to its

edge that the minimum bounding rectangle includes a part of the slope falling away

657. Notwithstanding the fact that the eastern—which is to say, furthest inland—part of the Survey Universe is characterized by increasingly frequent plateaux and escarpments, and that such features are even more common beyond the bounds of the area in which MHS was permitted to work. Their appearance is relatively abrupt, and as such, does not point to any very straightforward relationship between slope and distance inland.

658. Viz., as an absolute measure (3.4º) if not necessarily by rank-order. Genna's average slope is the highest of the surveyed areas, but this fact is almost entirely explicable by its proximity to a plateau edge. (Moreover, it goes to demonstrate how little variation there is, in regard of the regional topography; the difference between the highest and the lowest calculated average slope (1.0º, at Ditta Barbagallo) is a scant 2.4º.

from the plateau, proper.659 _{By virtue of their location, in other words, these sites} enjoyed a commanding view of the country spread out below.660

To all appearances, however, this advantage does not seem to have been decisive, at least during the Roman period. At the regional level, as we have already observed, there seems to have been a preference for sites in the open. At the level of thesite, an analogous phenomenon seems to exist. Of the sites located on the plateau, only one, Genna, is characterized by a preponderance of Roman materials near its edge.661 _{In the remaining three cases, the evidence for activity during this period is} not similarly concentrated. Casa Abbadessa and Ditta Barbagallo, as we have seen, are both characterized by a distribution with an identifiable center, but it is located at a somewhat greater remove from the edge. At the latter site, the distribution of Roman materials was centered on, if not actually to the east, of Sig. Barbagallo's house which lies approximately 140 m from the lip. At the former, it was centered on the prominence at DUs 2139–2142, which rises some 250 m to the south of the plateau's edge. Timpone Granatello, in contrast, is characterized by a much less concentrated distribution of finds. And to the degree that a centercanbe discerned, it seems to lie in the central third of the surveyed area, latitudinally speaking.662 _The most productive DU, 2112, lies c. 100 m distant from the edge to its east, and less than 200 m from the edge to the north.