The walled enclosure of Monte da Tumba (Torrão, Alentejo) is a good example of an intermediate abandonment in a site that originally (Silva & Soares, 1987) was considered to have a continuous sequence of occupation.
Image taken from: http://al-qasr-abu-danis.blogspot.pt/2009/04/accao-de-sensibilizacao-povoado-do.html
“The potent stratigraphic sequence of Phase I is interrupted by also potent wall ruins. Over these ruins a new occupation phase took place and new constructions are built. In this phase, a house seems to have been burned and the roof has fallen, preserving a material assemblage in good state. New ruins are then identified and a new (3rd) phase is defined, also with new constructions, like a central tower. According to the excavators, this sequence of continuous occupation is of 500 years.”
“In this discourse, no temporary abandonments were considered. In reality, it is not probable that two moments where powerful wall ruins are formed over which new construction are built and substantial changes in material culture can be observed (like the appearance of copper metallurgy in Phase 2 or the bell beakers in phase 3) didn’t implied interruptions in the occupation of the site. Ruins and generalized destructions as described do not happen in a day (unless by catastrophe) fallowed by a new occupation next day, with new constructions, new technologies and new artefacts previously inexistent. And we must remember we are talking about 500 years.”
(taken from Valera, 2003)
In fact, this sequence clearly suggests the existence of periods of abandonment in the sequence of occupation of the site. Determine the reasons of those abandonments, their dynamics and duration (all people left at the same time? They intend to come back? Were the same, their descendents or others that reoccupied the site? Etc.), and the reasons of reoccupation are central to understand the role of these sites in local and regional settlement networks and their historical circumstances throughout time. Abandonments are as important as occupations, just like what is missing is as important as what is present.
Silva, C.T & Soares, J. (1987), “O povoado fortificado calcolítico do Monte da Tumba I – escavações de 1982-86 (resultados preliminares)”, Setúbal Arqueológica, VIII, Setúbal, p.29-79.
Valera, António Carlos (2003), “Mobilidade estratégica e prolongamento simbólico: problemáticas do abandono no povoamento calcolítico do Ocidente Peninsular”, Era Arqueologia, 5, Lisboa, p.126-149. (http://www.academia.edu/attachments/2325706/download_file)