@article{PAR00000479,
  title = {{T}he stratigraphy, depositional processes, and environment of the late {P}leistocene {P}olallie-period deposits at {M}ount {H}ood {V}olcano, {O}regon, {USA}},
  author = {{T}houret, {J}.{C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {P}olallie eruptive period of {M}t. {H}ood, {O}regon, is the last major episode of eruption and dome growth, before the late {H}olocene activity which was centered at {C}rater {R}ock. {A} volume of 4-8 km(3) of {P}olallie deposits forms an apron of ca. 60 km(2) on the east, northeast and southeast flanks. {T}he {P}olallie deposits can be divided, stratigraphically, into four groups: {G}roup {I} rockslide avalanche and pyroclastic-flow deposits; {G}roup {II} debris-flow and pyroclastic- flow deposits that suggest some explosive activity and remobilization of pyroclastic debris in a glacial environment; {G}roup {III} block-and-ash flow deposits that attest to summit dome growth; {G}roup {IV} alternating debris-flow deposits, glacial sediments, and reworked pyroclastic-flow deposits that indicate a decrease in dome activity and an increase in erosion and transport. {G}roup {III} clearly indicates frequent episodes of dome growth and collapse, whereas {G}roups {II} and {IV} imply increasing erosion and, conversely, decreasing volcanic activity. {T}he {P}olallie period occurred in the late {P}leistocene during and just after the last {A}lpine glaciation, which is named {E}vans {C}reek in the {C}ascade {R}ange. {A}ccording to four {K}-{A}r age dates on lava flows interbedded with {P}olallie deposits and to published minimum {C}-14 ages on tephra and soils overlying these deposits, the {P}olallie period had lasted 15,000-22,000 years between 28-34 ka and 12-13 ka. {F}rom stratigraphic subdivisions, sedimentary lithofacies and features and from the grain-size and geochemical data, we infer that the {P}olallie depositional record is a result of the interplay of several processes acting during a long-lasting period of dome growth and destruction. {T}he growth of several domes near the present summit was intermittent, because each group of sediments encompasses primary (pyroclastic) and secondary (volcaniclastic and epiclastic) deposition. {D}irect deposition of primary material has occurred within intervals of erosion that have probably included meltwater processes from snow and ice fields. {I}nteractions of hot pyroclastic debris with glacier ice that capped the mountain at that time contributed to release meltwater, enhancing the remobilization of primary deposits. (c) 2005 {E}lsevier {B}.{V}. {A}ll rights reserved.},
  keywords = {volcaniclastic sediments ; stratigraphy ; eruption ; {M}t. {H}ood ; cascades},
  booktitle = {},
  journal = {{G}eomorphology},
  volume = {70},
  numero = {1-2},
  pages = {12--32},
  ISSN = {0169-555{X}},
  year = {2005},
  DOI = {10.1016/j.geomorph.2005.03.008},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00000479},
}