The archaeological site of La Serna in Arganda del Rey
A prehistoric settlement on the banks of the Jarama River
Description of the deposit
The La Serna deposit is located in the municipality of Arganda del Rey, close to the border with the municipality of Velilla de San Antonio. It is located on the highest point of a low hill, between the Cacerón and Vilches streams, tributaries of the Jarama. These geographical characteristics seem to have been the determining factor for the installation of the different human groups, looking for particular conditions in each period, always in function of agricultural resources and their proximity to natural communication routes.
So far, four major phases of occupation of the site have been distinguished:
- Neolithic. The oldest phase, which covers an area of approximately 1.100 m2.
- Chalcolithic. Which spans an area of 21.000 m2.
- Medium Bronze. Characterized by silo-type structures, in a space of 4.290 m2.
- Medium Bronze-Final Bronze. With a phase of Protocogotas and another of the Cogotas de Plenitud phase on approximately 42.000 m2.
Neolithic: At the southern end of the site, 14 silos have been documented around a paleocauce (a stretch of channel that has been abandoned due to the change in the course of a river). The ceramic material recovered in these structures presents decorations based on lines of discontinuous impressions, incised-printed lines, rectilinear fingered cords and decorations to the almagra that allow dating it between the first half of the XNUMXth millennium and the middle of the XNUMXth millennium BC.
Chalcolithic: Documented in an elevation of the land in which about 70 domestic structures excavated in the land appeared with a mouth diameter between 1,50 and 2 m and a depth that can also reach 2 meters. They were probably used as a storage place and later as garbage dumps. In some of them possible ritual deposits of fauna have been documented and in others a wide set of ceramic material (bowls, glasses, pots and especially pots), made entirely by hand, highlighting the pieces that have Campaniform style decoration.
Full Bronze: 139 structures have been excavated that appear highly concentrated, along with an old channel perpendicular to the river. The ceramic materials are made entirely by hand. The numerous presence of ceramic fragments with rough workmanship and simple shapes stands out, as well as more elaborate shapes such as cowled glasses. The scarce decorated fragments have incisions and ungulations on the edges and fingered cords and mamelons in the case of large storage pots.
Protocogotas - Cogotas: Located in the west of the deposit, on a slope with a slight slope towards the river. Approximately 550 structures have been excavated in this area, of which 290 are located on just over one hectare. Negative vertical structures of different sizes and shapes have been mainly documented, highlighting silos or circular holes of varying diameters and depths whose functionality seems to be storage and later reuse as garbage cans.
In the southern part, a series of structures identified as furnaces and hearths have been excavated, which are related to a metallurgical workshop. Along with them appeared a set of materials related to this activity, consisting of a multiple mold, with its main face prepared to obtain flat axes and with imprints on the sides to melt bars or preforms; a crucible of considerable dimensions, which preserves the remains of slag and a stone with a bowl. Metal objects such as punches and rods were also found.
The ceramic materials corresponding to this phase are entirely made by hand, with globular, frustoconical and fairing shapes prevailing, with fine and polished smoothing finishes or decorated with incisions. Within the Protocogotas Phase, the pieces with careful finishes predominate, highlighting the incised ceramics with simple decorations based on zigzag lines on both edges, as well as some triangular motifs with bands. In the Cogotas phase, the decoration of the ceramics is more elaborate, generalizing the Boquique technique or point in line and the excised motifs.
Image gallery
Archaeological performance
The archaeological action was motivated by mining exploitation to obtain gravel, in a farm on the terraces of the Jarama river called "IV Expansion to Valdocarros". Prior to the beginning of the exploitation, a surface prospecting and an appraisal with boreholes were carried out, during which the site was located and delimited, followed by the archaeological excavation of the areas that would be affected.