In-progress excavations of adjacent 2 x 2 m units at Mound 148, Kuulo Kataa. The base of units 70E 48-52N and 72E 50N have been excavated to depths ranging from 90-110 cm below datum. The large area of dark soil concentrated in unit 70E 50N (center) is intrusive pit fill which cut through the living surface at this mound level. An area of packed reddish-orange laterite gravel in unit 70E 52N (bottom, left) likely represents a prepared floor surface. To the right of the dark pit soil, in the boundary between units 70E 50N and 70E 48N, is a an irregularly shaped burned feature interpreted by archaeologists as likely associated with metalworking. Two radiocarbon samples associated with this burned feature had calibrated age ranges between c.1200-1400 CE. A cluster of hearth stones has been exposed in nearby unit 72E 50N (center photo). White bags filled with soil samples collected for flotation sit outside the excavated area together with excavation equipment. View looking eastwards. Kuulo Kataa, 11 July, 2000.
Excavations in unit 42N 4W have exposed clusters of pottery, grinding stones, tuyeres and an area of burned soil associated with metal working at Mound 6, Ngre Kataa. Foreground, left, a grinding stone (GS 08-10) rests with its working surface face down. It sits at a slightly higher level than a nearby (left) whole pottery jar (NK 08-406). To the right of these, a partial pot (NK 08-282) and a tuyere fragment (NK 08-284) are clustered together with two halves of a broken pottery jar, lying with its exterior surface facing down. To the south (behind), near the sign board and framed by photo scales, is a burned feature. Next to it sits a hand-held hammerstone (GS 08-11). Another partial pottery jar (NK 08-520) and a small flat grinding stone (GS 08-12) have been exposed to the left of the sign board at 77 cm below the unit's datum. The narrow dark bands visible in the soil are the traces of animal burrows. Photo scale adjacent to the sign board in centimeters. View looking south. Site Ngre Kataa. 7 July 2008.
A deeply worn grinding stone (grindstone 1, NK-08-112) removed from levels 1-2, unit 44N 4W, Mound 6, Ngre Kataa, photographed at the side of the excavation unit. The grinding stone was found in association with other grinding stones, tuyere fragments and whole and partial pots. When found, the grinding stone was oriented with its working surface facing downward. It was located adjacent to a concentration of dark soil (feature 1) that contained abundant oxidized sediment, slag and broken pottery. Archaeologists interpret the features at Mound 6 as facilities used to make and process metals. Photo scale in 5 centimeter increments. Ngre Kataa, 2 July, 2008.
The circular outline of a burned basin (Feature 3) is bracketed by photo scales (center) in unit 50N 4W (130 cm below the unit datum) at Mound 6. A pottery jar sits to the right side of the basin, its opening covered by a potsherd lid. To the left, a grinding stone sits, grinding surface down, over top of another pottery jar. Burned features like these were associated with metal working in this Mound 6 workshop area. Photo scale at bottom in centimeters. Site Ngre Kataa. 29 June, 2009.
The circular outline of a burned basin (Feature 3) is bracketed by photo scales (left of center) in unit 50N 4W (130 cm below the unit datum) at Mound 6. A pottery jar sits to the right side of the basin, its opening covered by a potsherd lid. To the left, a grinding stone sits, grinding surface down, over top of another pottery jar. Another grinding stone (far left) sits at a higher level in unit 50N 6W. A second burned feature is associated with a grinding stone tipped on its side, far right. Another pottery jar sits nearby, also lidded with a broken sherd. Burned features like these were associated with metal working in this Mound 6 workshop area. Photo scale at bottom in centimeters. Site Ngre Kataa. 29 June, 2009.
A perforated pottery jar lidded with the pedestaled base of another pot sits in situ at the base of level 6, unit 46N 2W at Mound 6. The pot contained eight cowries and is interpreted by archaeologists as a shrine pot placed in association with metalworking facilities. Photo scale in 5 cm increments. Site Ngre Kataa. 24 June, 2009.
The mouth of a perforated shrine pot (left) is covered with the pedestaled base of another pot. It remains in situ as the surrounding areas of unit 46N 2W are excavated to lower levels. Behind, the stratified layers of Mound 6 are visible in the unit's north wall. Center (back) are a series of anvil and grinding stones exposed at higher mound levels in other excavation units. During excavations in 2008, a cluster of four anvil/grinding stones was found at a level slightly higher than but adjacent (left/west) to the perforated pot. At right, in lower levels, two grinding stones rest at an angle in association with a burned feature. Archaeologists interpret Mound 6 as a metallurgical workshop at which stratified levels built up through repeated use of the same location. Photo scale in centimeters. Site Ngre Kataa. 2 July, 2009.
Iron slag is formed as a byproduct of iron smelting. Here a large slag nodule has broken in half, revealing its interior texture. At the archaeological site of Ngre Kataa, large chunks of 'bubbly' slag like this were occasionally found in household and other contexts, away from areas otherwise associated with metal-working activities. Potters at the time of the site's occupation had begun to use crushed iron slag as a tempering agent in their potting clays, which may explain why large nodules were being carried and cached in areas away from metal-working locations. Ngre Kataa, June, 2008.
Iron slag is formed as a byproduct of iron smelting. Here a large slag nodule has broken in half, revealing its interior texture. At the archaeological site of Ngre Kataa, large chunks of 'bubbly' slag like this were occasionally found in household and other contexts, away from areas otherwise associated with metal-working activities. Potters at the time of the site's occupation had begun to use crushed iron slag as a tempering agent in their potting clays, which may explain why large nodules were being carried and cached in areas away from metal-working locations. Ngre Kataa, June, 2008.
View across open excavations in an area (mound 6) that archaeologists interpret as a metallurgical workshop. The photo centers on units 46N 8W (foreground) and the southern half of 48N 8W, the north wall of which (at 47N) can be seen behind the sign board. The exposed areas were excavated in 2008 and the photo taken in preparation for 2009 excavations. Traces of circular burned features, red-orange and yellow in color, can be seen in the freshly scraped surface of these units. The uppermost north arrow sits to the right (east) of the circular outline of a still-buried everted-rim jar. Another everted-jar rim can be seen exposed in the north wall at 47N. This rim and associated artifacts formed cluster B, part of a larger shrine feature (clusters A-D) that extended across the northern half of unit 48N 8W (beneath and behind the small tree trunk visible above and left of the sign board). Cluster A (unit 46N 8W) comprised a large pottery bowl surrounded by six iron bangles that was removed in 2008. It was positioned above and slightly west (left) of the burned feature (center photo) that is intersected by a tree root. Cluster B included the artifacts seen here in the north wall at 47N, together with an associated cluster of a pedestal-handled pot lid, dog skull and jaw bones revealed by further excavation beneath and west (left) of the tree stump. In the upper right of the photo (north and east), insitu anvil (GS 09-15, left) and grinding (GS 09-12, right) stones are visible in unit 50N 6W. Photo scales marked in 5 cm increments and measuring tape marks 2 m. Arrows pointing north. Site Ngre Kataa. 6 June 2009.