Resumen de Arte rupestre temprano en el Norte de Uruguay
In the north of Uruguay important archaeological sites have been located in the last fifteen years, sites that involve a high number of rock engravings, completely unknown to date. These sites reveal a very rich cultural heritage, which include thousands of petroglyphs. The engravings with designs of geometric type, show a variety of motives, with marked recurrence of some of the expressions. At present there is in development the initial phase of a long scope project destined to the integral archaeological investigation and later handling (preservation, put in value, socialization), of the cultural testimonies mentioned. At present we have carried out the systematic report of an extensive area that involves more than 14,000km2, where the biggest incidence of these testimonies occur. Given the scope of the studies, the available information is still fragmentary, both with regard to the societies responsible for such manifestations and their temporary place. Excavations were conducted in four places, selected for their diagnostic interest They allow to link the above mentioned cultural testimonies with aceramic hunting societies. The processes of formation fulfilled in such places, joined to the characteristics of the physical environment, made it difficult to date and establish a precise chronology. The edaphics studies developed put these human occupations to at least the Middle Holocene in a panorama substantially differently from the current one, with a predominance of an arid and cold environment.
The landscapes in which these demonstrations are registered comprise flat surfaces of basaltic origin with only minor structural elevations, where outcrops with veins of silicified sandstone or basalt type can be seen. These geological veins, in particular those of silicified sandstone, are the support for the manifestations of paleo art mentioned. Petroglyphs may appear grouped, with more than 100 engravings per site, or isolated, with a low number of representations. The designs are of a geometric type, abstract, made by pecked and/or abrasion techniques (curettage and even polished).
The grooves or rectilinear lines present a section in �V�, or in "U". The rock supports can have varied sizes of more than one meter to a few centimetres. From a morphologic standpoint, we find designs that show simple motives or a certain complexity, carried out, seemingly, with a unitary line, in which all the lines or surfaces link in only one entity. There are also simple compound motives resulting from the reiteration of simple figures or complicated designs, "meandering" or grilled, often without geometric rigor. In many cases, the designs are highlighted by a major thickness or depth of the lines, or an emptying of the figure. There are even motives that adopt aspects of �bas-reliefs�, which combine diverse execution skills. Many of the sites show archaeological material on the surface and/or in layers. The lithic material recovered includes many instruments seemingly related to the completion of the engravings, or of a general utilitarian character, achieved by percussion and abrasion skills (stones of �boleadoras�, �lenticular�). Flint knapping activities are in general limited. The raw material used for the most part includes quartzite and in a minor number chalcedony and they often come from local quarries. Occupations are developed in the areas closest to the outcrop (petroglyphs), thinning rapidly as we move away from it.
In spite of the isolation and the general ignorance shown by local populations regarding the numerous sites in the region, big changes have already been seen in recent times, where actions have put in serious risk the cultural heritage involved. To the geophysical and geochemical alterations of a natural origin is now added actions of vandalism, intentional or not, which led some panels and even entire sites to destruction or at least, alteration. In the region, the extraction of stone (sandstones) turns out to be relatively intense, with the development of different quarries, therefore the risks for our regional archaeological heritage are really high. Such a situation, motivated us - although the project is in a primary stage and information of general character is particularly insufficient - to include inside the project actions of diffusion, to design an Archaeological Park and to analyze possible socialization strategies through animation, involving public and private entities of the area in its management. The aim is to reach a better comprehension of the prehistoric populations and their environment and thus to generate a tool of evaluation and preservation of such heritage.
