The Ngovo Group: an industry with polished stone tools and pottery in Lower Zaïre

Summary Now, for the first time, it is possible to place in an exact archaeological context the polished tools which have been collected for many years on the surface in the savanna immediately to the south of the equatorial forest. In Lower Zaïre, in an area of 6000 km², polished tools have been found systematically associated with a particular type of pottery. This pottery, which was previously known as Groupvi pottery and which we propose calling Ngovo group pottery is very distinctive.Although faunal remains associated in one case were of wild animals, someElaeïs andCanarium nuts could indicate the beginnings of agriculture. A series of dates in good agreement place these polished tools and this pottery within the last two centuries bc.At the present time, iron-working in Lower Zaïre has not been dated prior to the second century ad. This Early Iron Age is associated with the Kay Ladio group pottery which is possibly derived from the Ngovo group.

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Résumé Pour la première fois, il est possible de préciser le contexte archéologique des outils polis que depuis longtemps on recueillait en surface dans les savanes immédiatement au sud de la forêt équatoriale.Au Bas-Zaïre, dans une zone de plus de 6000 km², des outils polis ont été trouvés systématiquement en association avec une céramique d'un type particulier. Cette céramique, connue précédemment sous le nom de céramique du groupevi et que l'on propose d'appeler dorénavant groupe de Ngovo, est très caractéristique.Bien que les restes de faune qui y sont associés dans une grotte soient ceux d'animaux sauvages, des noix d'Elaeïs et deCanarium indiquent peut-être un début d'agriculture.Une série de datations remarquablement convergentes placent ces outils polis et cette céramique durant les deux derniers siècles bc.La métallurgie n'est jusqu'à présent pas datée au Bas-Zaïre avant le 2e siècle ad. Cet âge du fer ancien est associé à la céramique du groupe Kay Ladio qui dérive peut-être du groupe de Ngovo.

     

ON THE STABILITY OF HOUSING SECTOR INTERACTION: EVIDENCE FROM 42 METROPOLITAN AREAS*

ABSTRACT. Residential vacancy chain models based on White's (1971) application of Markov chain theory are used to simulate flows of housing vacancies through a set of interdependent housing market sectors. Measures of housing sector interaction are derived from such models. Our purpose here is to address the issue of time stationarity raised by their use. U.S. census data are available to calibrate such models at two, and sometimes three, points in time. Data from 42 different SMSAs are used to generate 56 cross-temporal comparisons with interobservation periods ranging from three to eight years. Stability of interaction is addressed from two perspectives–the sectoral perspective and the areawide perspective. Results are mixed and depend upon which measure of interaction is used, which perspective is addressed, and the duration of the interobservation period. However, within limits, findings support continued use of vacancy chain models.     

GAS LIQUID CHROMATOGRAPHIC ANALYSIS OF FATTY ACIDS IN FOOD RESIDUES FROM CERAMICS FOUND IN THE SOUTHWESTERN CAPE,SOUTH AFRICA

Gas liquid chromatography was used to analyse residues adhering to the inside of excavated potsherds from dated South African sites. The results suggested marine animal fat, possibly seal, had been cooked in the vessels. Fat of modern seals was baked and also analysed as a control sample. This gave similar results. The importance of seals in the prehistoric diet of the Southwestern Cape is supported by a large number of seal bones in the associated faunal material.     

TRADE CENTER EVOLUTION IN THE GREAT PLAINS*

ABSTRACT Empirical analysis has lagged behind the impressive additions to the theoretical literature on trade center systems during the past 15 years. This study of the trade center system in Saskatchewan is an attempt to begin to redress the imbalance and to test some of the recently formulated theoretical propositions. Communities are identified according to functional classifications for 1961 and 1981 with the aid of a cluster analysis program, and the validity of the groupings are verified using multiple discriminant analysis. Changes in the size, spacing, and function of clusters and individual communities during the 20-year interval are described and an effort is made to prdvide explanations for the changes observed.     

A CONTEXTUAL ANALYSIS OF THE JOURNEY-TO-SHOP WITH PRICE UNCERTAINTY*

ABSTRACT In this paper we extend the contextual theory of demand to consider rational consumer behavior when the household must deal with some random fluctuation in the prices it faces. Prices at stores reflect “advertised specials,” which are potential cost reductions random across goods, and random in-store price changes, which can only be observed by visiting the store. Our theory of rational behavior includes: (1) calculation by the household of an ex ante plan for its planning period; (2) modification to take account of advertised specials; and (3) rational search behavior to take advantage of random fluctuations observable only on a given day. This theory utilizes an active cash balance as a buffer against random variations from planned daily expenditures, and reformulations of trip circuits to account for patterns of cost-minimizing search.