A Raman spectroscopic study of glass trade beads excavated at Mapungubwe hill and K2, two archaeological sites in southern Africa,raises questions about the last occupation date of the hill

Thousands of glass trade beads were excavated over a 75 year period on Mapungubwe Hill and at K2, two archaeological sites in the Limpopo valley, South Africa. An assemblage of 175 beads that appeared to be different in shape, size and colour (red, yellow, green, blue, white, black, pink, plum) was studied with Raman scattering. At least seven different chromophores or pigments (lazurite, lead tin yellow type II, Ca/Pb arsenate, chromate, calcium antimonate, Fe–S “amber” and a spinel) have been identified. Pigment identification allows the recognition of specific productions and indicated that many of the pigments colouring the beads excavated on Mapungubwe hill were manufactured after the 13th century, confirming the presence of modern beads in the archaeological record, some dating from the 19th century. This date is in agreement with the last occupation date for the hill suggested by the earlier excavators and raises questions about the revision of this date to 1290 AD by archaeologists in the 1970’s.     

Urban experimentation and institutional arrangements

ABSTRACT

Currently little is known about how institutional arrangements co-evolve with urban experimentation. This paper mobilizes neo-institutional literature and recent urban experimentation literature as a framework to explore how and why institutional arrangements differ across urban contexts. Empirically the paper focusses on smart city initiatives in Amsterdam, Hamburg and Ningbo. These three cities are frontrunners in adopting a comprehensive smart city agenda, but they do so in different ways. The paper examines regulative, normative and cognitive elements of institutional arrangements, explores how they shape experimentation, and reflects on their place-based specificities. The comparative analysis suggests that the focus of, and approach to, experimentation can be understood as resting in a (possibly unique) combination of strategic agency and dynamics at multiple spatial scales.