TOzzBR] EXCAVATION AT SANTIAGO AHUITZOTLA, MEXICO 25 



Pit XVI. — The floor in the western purt of Room IX was badly 

 cracked and depressed. This subsidence extended into Room ^^I. 

 This floor was removed and an excavation (pi. 2, Pit XVI; also sec. 

 g-h ) made at this point. We soon found a thick bed of ashes. This 

 place had evidently been used as a dumping ground for refuse from 

 the fires of the inhabitants previous to the erection of the Southern 

 Extension. The weight of the building was evidently too great for 

 the sustaining power of the ashes, and a subsidence was the result. 

 Six tunnels were run out from tlie main hole in order to ascertain 

 the extension of the ash deposit and the possible presence of lower 

 floors. 



Pit XV . — A depression in the floor of Room XI similar to that in 

 Room IX was noted. A pillar of adobes (similar to 12 in the same 

 room) had fallen, owing to the subsidence of the floor. An excava- 

 tion (pi. 2, Pit XV; also sec. /-/') was made here and a bed of ashes 

 found, as in the previous case. Two tunnels were run out, that to 

 the north extending under a great part of Room XI. Xo floors or 

 walls were found in any of these tunnels running from the two 

 excavations. 



Pits A'AVT^, XXV. — A third bed of ashes was found over the 

 mouths of the four wells, as already pointed out (pi. 2, sees, i-j, h-l). 

 Ashes also filled the wells, so that the deposition of the ash layer 

 and the filling in of the wells undoubtedly occurred at the same time. 

 As previously mentioned, the ashes in these three deposits and in 

 the wells were a most prolific source of shards and several unbroken 

 ollas. There were probably three times as many shards found in 

 these beds of ashes as in all the rest of the site put together. They 

 all invariably belong to the Toltec culture. 



Ash stratum. — In addition to the thick beds of ashes just described, 

 mention should be made here of the stratum of ashes found under 

 the Main Structure, and shown in plate 2, sections i-j, h-l. This 

 layer of ash averages 0.5 m. in thickness and is about 0.5 m. below 

 the floor of the rooms in the Main Structure. On the southern side 

 the stratum seems to end just inside the Terrace. On the west the 

 ash layer is found extending to the other side of the modern road. 

 On the north the same stratum runs under Floor B', and on the east 

 it ends inside the Terrace. Under Floor A a second stratum of ash 

 runs above the first and above the level of the rooms in the Main 

 Structure. 



Sequence. — It is plain that the history of the site covered a con- 

 siderable period of time extending from the Teotihuacan into the 

 Aztec culture. There are man}' changes, additions, and alterations 

 in the plans and it has already been pointed out how floor covers 

 floor and wall covers wall. The possible sequence in the erection of 



