Q02-2 "Quarry Pit"

The upper area of Maymeja, as well as the eastern flanks of Cerro Hornillo, are blanketed with small fragments of obsidian that appear as lag gravels among the tephra soils of the area (Section 4.5.1). In particular, flows and large nodules of obsidian are exposed through erosion in some areas, which suggests that underneath the tephra are larger nodules, but one has to excavate for them. On the north side of Maymeja, in an area heavily eroded by glaciers, a flow of obsidian [Q02-1] was observed but it contained vertical, subparallel fractures and was generally not suitable for tool production.

At the same altitude as this natural flow, but 700m to the south and across several moraines is a quarry pit [Q02-2] located in an area where the ashy soil was particularly light-colored. Similar open-air obsidian quarries have been described in central Mexico as "doughnut quarries" (Healan 1997) and "extracción a cielo abierto" (Darras 1999: 80-84). See Section 7.4.1 for further details on this quarry pit.

The coordinates of the Q2-2 pit are 71.5355° S, 15.6423° W (WGS84 datum), and it lies at 4972 masl. Around this quarry pit many small obsidian nodules in a depression were encountered that were typically < 5cm in size, but a few were closer to 15cm on a side. There is a smaller mound of sandy soil and small fragments of obsidian inside the larger quarry pit, suggesting that someone has attempted to further excavate the quarry pit in the more recent past.

Figure 6-45. Testing at Quarry Pit Q02-2 with 1x1 test unit Q02-2u3. Snow remains in the pit.

During the 2003 field season a test unit was placed in the debris pile immediately downslope of this quarry pit. The quarry pit and the test unit results are described in more detail in Section 7.4.1 and a brief discussion of ancient quarrying methods can be found in Section 8.3.2.