Tecnologia lítica e comportamento humano no pleistocénico médio final do Alto Ribatejo: estudo da indústria lítica da Ribeira da Ponte da Pedra
Ficheiros
Data
2014-11-13
Autores
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
A Ribeira da Ponte da Pedra é um sítio arqueológico localizado no terraço
fluvial Q3/T4 do médio Tejo em território português. Para além das ocupações do
Pleistocénico Médio Final que focamos nesta tese, encerra ainda vestígios do Paleolítico Médio e do Paleolítico Superior.
Os vestígios do Pleistocénico Médio Final contêm artefactos líticos em 12
unidades litológicas distintas que representam quatro morfologias de deposição: uma barra (formada por areias grosseiras avermelhadas e seixos); um canal (preenchido com
blocos e seixos grandes, até 35 cm, e areias grosseiras avermelhadas) que corta a barra;
uma planície de inundação de depósitos de grãos finos (cinzento a amarelo); e canais
transversais (preenchidos com areias avermelhadas e seixos até 10 cm) com um
contacto muito erosivo com o depósito de planície de inundação. Naturalmente, a
natureza destes depósitos e a consequente posição secundária dos artefactos dificultou a
nossa análise tecnológica. Nestes depósitos foram exumados cerca de 1500 artefactos que foram analisados no presente trabalho desde uma perspectiva tecnológica, mas também morfológica, recorrendo a experimentações e análises funcionais complementares.
O estudo dos artefactos provenientes das várias unidades litológicas revelou-se
bastante homogéneo, não se verificando significativas diferenças entre estas, o que nos permitiu uma reconstrução hipotética das cadeias operatórias e respectivos objectivos
técnicos. Existem, portanto, duas cadeias operatórias: uma orientada para o retoque de seixos para obter pequenos utensílios; outra que consiste no talhe dos seixos rolados
para a obtenção de lascas utilizadas em bruto ou retocadas (ao mesmo tempo, alguns
destes seixos talhados são utilizados como Choppers). Esta cadeia operatória tem 3
variáveis: 2A que consiste na produção seixos com um levantamento; 2B constituída
por seixos com 2, 3 ou mais levantamentos, consideramos a produção de artefactos
bifaciais uma variante rara desta cadeia; 2C representada pela exploração de núcleos de várias tipologias, sendo os núcleos sobre lasca uma variante rara desta cadeia.
O conjunto é dominado pela presença de lascas corticais e semi-corticais, entre
estas contam-se um largo número de lascas retocadas, algumas com retoques que
denominámos «informais». Tratam-se de modificações irregulares, por vezes
descontínuas, variáveis na posição, alternas e alternantes, abruptas e semi-abruptas e
que por vezes delineam um gume. Estes retoques «informais» também se verificam nas margens de alguns seixos talhados. Para melhor entender esta ocorrência foram feitas várias séries de experimentações que, apesar de necessitarem de mais estudos, indicam
que estes retoques «informais» podem ser consequência da utilização em diversas
actividades de subsistência, em particular no trabalho de matérias dura ou semi-duras
como madeira e osso. Aliás, os estudos funcionais realizados sobre uma amostra de
algumas dezenas de lascas indicam que no sítio da Ribeira da Ponte da Pedra foram
desenvolvidas diversas actividades de subsistência.
Os dados obtidos com o estudo da Ribeira da Ponte da Pedra foram enquadrados
no conjunto das ocupações do Pleistocénico Médio do Vale do Tejo em território
português. Para tal foi elaborado um «estado de arte» sobre os principais sítios conhecidos: Monte Famaco, Fonte da Moita, Galeria Pesada, Vale do Forno 1,3 e 8 e Samouco. Entendemos que o sítio da Ribeira da Ponte da Pedra está articulado com estes sítios, não necessariamente numa perspectiva estritamente sincrónica, na obtenção de recursos bióticos e abióticos. No que diz respeito aos recursos bióticos avançamos com a hipótese de a Ribeira da Ponte da Pedra ter uma articulação com os sítios em gruta no complexo cársico do Almonda, estando localizada num ambiente paisagístico, planície ribeirinha, que permite a captura de animais que não existem a maior altitude.
Esta complementaridade alargar-se-ia à obtenção de matérias-primas.
Cremos que a Ribeira da Ponte da Pedra se localiza numa zona onde se
encontrava largamente disponível matéria-prima de boa qualidade, tanto em textura,
como em volumetria, para a produção de utensilagens sobre seixo e sobre lascas de
médias e grandes dimensões. É por essa razão que avançamos a hipótese de uma
articulação com os demais sítios do Vale do Tejo, cujas comunidades humanas na sua
gestão nómada dos recursos territoriais obteriam nesta zona matéria-prima e
eventualmente outros recursos. O registo arqueológico, por agora, não nos permite
confirmar estas hipóteses, no entanto, entendemos ser um caminho a seguir em futuras
pesquisas de forma a perspectivar o povoamento do Vale do Tejo numa lógica de
complementaridade e integração entre os vários locais com vestígios de ocupação
humana.
The Ribeira da Ponte da Pedra is an archaeological site located in the Q3/T4 fluvial terrace in the middle Tagus of the portuguese territory. Beyond the Final Middle Pleistocene occupations that we study in this thesis, it also contains remains of Middle and Upper Paleolithic. The Final Middle Pleistocene remains include lithic artifacts in 12 distinct lithological units, which represent four depositional morphologies: a bar (formed by reddish coarse sands and pebbles); a channel (filled with blocks and large pebbles, up to 35 cm in size, and reddish coarse sands and pebbles) that cuts through the bar; a floodplain of fine grain deposits (grey to yellow); and transversal channels (filled with reddish sands and pebbles up to 10 cm in size) with very erosive contact with the floodplain deposit. Naturally the nature of these deposits and the consequent secondary position of the artifacts created a difficulty for the technological analysis. Around 1500 lithic artifacts were recovered in these deposits that were analyzed from a technological perspective, as well as a morphological one, also using complementary experimentations and functional analysis. The study of the artifacts derived from the different lithological units revealed quite homogenic features, without significant differences amongst them, which allowed us to form the hypothetical reconstruction of the reduction sequences and their technical objectives. Therefore there are two reduction sequences: one orientated towards the retouch of pebbles to obtain small tools; the other consists in the knapping of pebbles to obtain flakes used with or without retouch (simultaneously some of these knapped pebbles are used as Choppers). This last reduction sequence has 3 variables: 2A encompasses the production of pebbles with one removal; 2B is composed by pebbles with 2, 3 or more removals (we consider the production of bifacial artifacts a rare variant of this sequence); 2C is represented by the exploitation of cores of different typologies, being the flake cores a rare variant of this sequence. The assemblage is dominated by the presence of cortical and half cortical flakes, among these there are numerous retouched flakes, some of them we considered as «informal» retouch. This is characterized by irregular edge modifications, sometimes discontinuous, variable in its position, altern and alternating, abrupt or semi abrupt and occasionally they delineate an active edge. These «informal» retouch are also visible in some worked pebbles. To better understand these features we engaged a series of experimentations and functional studies that, despite the need for further research, indicate that these «informal» retouch might be the consequence of blanks used in various subsistence activities, namely the work of hard and semi hard materials, such as wood and bone. In fact, the functional studies done over a sample of some dozen flakes point out that different subsistence activities were engaged in Ribeira da Ponte da Pedra. The data obtained in the present study was framed within the known human occupations of the Middle Pleistocene of the Tagus valley in the portuguese territory. To do so, we elaborated a «state of the art» about the main sites: Monte Famaco, Fonte da Moita, Galeria Pesada, Vale do Forno 1, 3 e 8 and Samouco. We understand that the site of Ribeira da Ponte da Pedra is articulated with these other sites, not necessarily in an absolute synchronic way, in the obtention of biotic and abiotic resources. In what concerns to the capture of biotic resources, we believe that Ribeira da Ponte da Pedra might have an articulation with the sites in the Almonda karstic complex, since it is located in a landscape environment – river plain with small hills – that allows the capture of species of animals that do not exist in higher altitudes. This complementariety would also comprise the gathering of lithic raw materials. We believe that Ribeira da Ponte da Pedra is located in an area where good quality raw material, both in texture and volumetry, was largely available for the production of tools on pebbles and on large to medium size flakes. It is for this reason that we advance the hypothesis of an articulation with the other mentioned sites of the Tagus valley, whose human communities, within their nomadic management of territorial resources, would obtain good raw materials in this area. For the moment the archaeological record does not allow the entire confirmation of these hypotheses, nevertheless, we are inclined to consider this as the path for future research, in order to form a perspective of the Tagus valley peopling in complementariety logic, integrating the several sites with remains of human occupation.
The Ribeira da Ponte da Pedra is an archaeological site located in the Q3/T4 fluvial terrace in the middle Tagus of the portuguese territory. Beyond the Final Middle Pleistocene occupations that we study in this thesis, it also contains remains of Middle and Upper Paleolithic. The Final Middle Pleistocene remains include lithic artifacts in 12 distinct lithological units, which represent four depositional morphologies: a bar (formed by reddish coarse sands and pebbles); a channel (filled with blocks and large pebbles, up to 35 cm in size, and reddish coarse sands and pebbles) that cuts through the bar; a floodplain of fine grain deposits (grey to yellow); and transversal channels (filled with reddish sands and pebbles up to 10 cm in size) with very erosive contact with the floodplain deposit. Naturally the nature of these deposits and the consequent secondary position of the artifacts created a difficulty for the technological analysis. Around 1500 lithic artifacts were recovered in these deposits that were analyzed from a technological perspective, as well as a morphological one, also using complementary experimentations and functional analysis. The study of the artifacts derived from the different lithological units revealed quite homogenic features, without significant differences amongst them, which allowed us to form the hypothetical reconstruction of the reduction sequences and their technical objectives. Therefore there are two reduction sequences: one orientated towards the retouch of pebbles to obtain small tools; the other consists in the knapping of pebbles to obtain flakes used with or without retouch (simultaneously some of these knapped pebbles are used as Choppers). This last reduction sequence has 3 variables: 2A encompasses the production of pebbles with one removal; 2B is composed by pebbles with 2, 3 or more removals (we consider the production of bifacial artifacts a rare variant of this sequence); 2C is represented by the exploitation of cores of different typologies, being the flake cores a rare variant of this sequence. The assemblage is dominated by the presence of cortical and half cortical flakes, among these there are numerous retouched flakes, some of them we considered as «informal» retouch. This is characterized by irregular edge modifications, sometimes discontinuous, variable in its position, altern and alternating, abrupt or semi abrupt and occasionally they delineate an active edge. These «informal» retouch are also visible in some worked pebbles. To better understand these features we engaged a series of experimentations and functional studies that, despite the need for further research, indicate that these «informal» retouch might be the consequence of blanks used in various subsistence activities, namely the work of hard and semi hard materials, such as wood and bone. In fact, the functional studies done over a sample of some dozen flakes point out that different subsistence activities were engaged in Ribeira da Ponte da Pedra. The data obtained in the present study was framed within the known human occupations of the Middle Pleistocene of the Tagus valley in the portuguese territory. To do so, we elaborated a «state of the art» about the main sites: Monte Famaco, Fonte da Moita, Galeria Pesada, Vale do Forno 1, 3 e 8 and Samouco. We understand that the site of Ribeira da Ponte da Pedra is articulated with these other sites, not necessarily in an absolute synchronic way, in the obtention of biotic and abiotic resources. In what concerns to the capture of biotic resources, we believe that Ribeira da Ponte da Pedra might have an articulation with the sites in the Almonda karstic complex, since it is located in a landscape environment – river plain with small hills – that allows the capture of species of animals that do not exist in higher altitudes. This complementariety would also comprise the gathering of lithic raw materials. We believe that Ribeira da Ponte da Pedra is located in an area where good quality raw material, both in texture and volumetry, was largely available for the production of tools on pebbles and on large to medium size flakes. It is for this reason that we advance the hypothesis of an articulation with the other mentioned sites of the Tagus valley, whose human communities, within their nomadic management of territorial resources, would obtain good raw materials in this area. For the moment the archaeological record does not allow the entire confirmation of these hypotheses, nevertheless, we are inclined to consider this as the path for future research, in order to form a perspective of the Tagus valley peopling in complementariety logic, integrating the several sites with remains of human occupation.
Descrição
Tese de Doutoramento em Quaternário, Materiais e Cultura
Palavras-chave
Indústria lítica , Ribeira da Ponte da Pedra (Santarém, Portugal)