The Application of Clay Mineralogical Analysis to the Reconstruction of a Greek Bronze Age Coastal Environment

摘要

The Argive plain is a subsiding coastal basin in the Peloponnese, Greece. Although there are varying explanations for the rise of a complex society on the Argive plain in the Greek Early Bronze Age (3000-2000 B.C.), archaeologists believe that there is a close link between changes in the environment and human activity. Previous geoarchaeological analysis of the Pleistocene and Holocene stratigraphy of the Argive plain has delineated cycles of marine transgression/regression (Zangger 1991, 1993). On the west side of the bay Zangger's Holocene reconstruction for the plain has a freshwater lake, which experienced a major alluviation event in the Early Helladic II period (2500-2150 B.C.). He considers this event to be the result of soil erosion caused by increased human activity. The east side of the bay was a marine environment. Certain aspects of Zangger's Early Bronze Age landscape reconstruction could equally apply to Holocene deltaic formation as suggested by Stanley and Warne (1997). Clay-rich sediments from outcrops on the Argive plain were compared with Zangger's Holocene stratigraphy. These sediments were examined using X-ray diffraction and particle size analysis. This was done in order to more fully understand the transition from marine to fluvial conditions. The results of particle size analysis and determination of clay mineral content and quantity strongly suggest that the depositional environment is better explained as being deltaic. The variability over short intervals of the sand-silt-clay ratios and the differences in the smectite-illite-kaolinite ratios fit well with a prograding delta.