Tecolote (owl) Cone viewed from the south. Tecolote yielded an age of 27 ± 6 ka by ⁴⁰Ar/³⁹Ar (Gutmann et al., 2000). Tecolote is a large cinder cone with an intricate history involving multiple eruptive events, intrusion and leakage of contained magma, and various episodes of structural disturbance. Many fault scarps and collapse pits are evident in this view, as are lava flows emanating from low on the side of the cone. Large masses of cinder derived from cone walls were carried away by lava flowing from the breach in its northern wall; these appear as hummocks in this photo.