Sand Mountain Field

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 44.38°N
  • 121.93°W

  • 1664 m
    5458 ft

  • 322040
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Sand Mountain Field.

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The Sand Mountain volcanic field consists of a group of 23 basaltic and basaltic-andesite cinder cones along a N-S line immediately west of the Cascade crest NW of Mount Washington. Two cone alignments trending NNW and NNE intersect near the largest cinder cone, Sand Mountain. A series of young, unvegetated lava flows originating from vents on the west side of the chain of cones were erupted primarily during a 1000-year period from about 3000-4000 years ago. Lava flows traveled predominately to the west, blocking local drainages and forming several small lakes. The Lost Lake cinder cone group at the north end of the chain was active about 2000 years ago.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
0070 ± 150 years Unknown Confirmed 2 Radiocarbon (corrected) Lost Lake cones
0800 BCE ± 300 years Unknown Confirmed 2 Radiocarbon (corrected) Nash Crater
0900 BCE ± 100 years Unknown Confirmed 2 Radiocarbon (corrected) North Sand Mtn and other cones
1740 BCE ± 300 years Unknown Confirmed 2 Radiocarbon (corrected) North and south of Sand Mountain
2290 BCE ± 300 years Unknown Confirmed 2 Radiocarbon (corrected) Nash Crater and other cones

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Cones

Feature Name Feature Type Elevation Latitude Longitude
Central Group Pyroclastic cone 44° 24' 0" N 121° 56' 0" W
Little Nash Crater Pyroclastic cone 1255 m 44° 26' 0" N 121° 57' 0" W
Lost Lake Group Pyroclastic cone 1458 m 44° 26' 0" N 121° 56' 0" W
Nash Crater Pyroclastic cone 1462 m 44° 25' 0" N 121° 57' 0" W
Sand Mountain Cones Pyroclastic cone 1664 m 44° 23' 0" N 121° 56' 0" W
South Group Pyroclastic cone 44° 21' 0" N 121° 56' 0" W
The Sand Mountain volcanic field contains a group of 23 cinder cones erupted along a N-S line NW of Mount Washington. Two cone alignments diverge at the highest cone, Sand Mountain; this view looks along the NNE alignment, with Mount Jefferson visible in the distance. The Sand Mountain cones and associated lava flows were erupted between about 3000 and 4000 years ago.

Photo by Lee Siebert, 1981 (Smithsonian Institution).
Nash Crater cinder cone, viewed from Little Nash Crater to the NW, is part of a cone alignment that diverges to the NNW from Sand Mountain. Lava flows from Nash Crater were erupted about 3850 years ago and traveled to the west, where they blocked a stream drainage, forming Fish Lake.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
The flattened snow-covered summit of Little Nash Crater, a scoria cone of the Sand Mountain volcanic field in the central Oregon Cascades, has been extensively quarried to provide aggregate for highway construction. Reddish, oxidized scoria from Little Nash Crater can be seen in road surfaces in the Santiam Pass area.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
A blocky lava flow, still largely unvegetated, was erupted about 3850 years ago from Nash Crater in the Sand Mountain volcanic field of the central Oregon Cascades. This and contemporaneous lava flows blocked local drainages, forming Lava Lake and Fish Lake.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
Sahalie Falls were formed when lava flows from the Sand Mountain volcanic field that were erupted about 3000 years ago traveled to the west, blocking the channel of the ancestral McKenzie River. Wind-blown spray from the falls nourishes bright-green mosses that drape rocks around the falls.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
The Lost Lake cinder cones, seen here from the east across Lost Lake near Santiam Pass, are the youngest known volcanic products of the Sand Mountain volcanic field. The cones were formed about 1950 radiocarbon years ago during eruptions along a N-S-trending fissure at the northern end of the Sand Mountain cone group. Growth of the chain of cones blocked Lost Creek, forming Lost Lake.

Photo by Lee Siebert, 1997 (Smithsonian Institution).
The snow-capped Sand Mountain cinder cones on the horizon were the source of the barren lava flow forming the far shore of Clear Lake. The lake was created when a series of lava flows erupted from the Sand Mountain volcanic field traveled to the west and blocked the drainage of the ancestral McKenzie River. Standing stumps of the forest drowned by the rising lake waters have been radiocarbon dated at about 3000 years ago and are still visible today.

Photo by Lee Siebert, 1999 (Smithsonian Institution).
Fish Lake is an ephemeral lake on the western side of the Cascade Range crest that fills with water (as seen here after spring snow-melt) but drys up during the summer. The lake was formed when the Fish Lake lava flow from Nash Crater of the Sand Mountain volcanic field dammed local drainages. This flow and the Lava Lake flow from cinder cones at the northern half of the chain were both extruded about 3850 radiocarbon years ago.

Photo by Lee Siebert, 1999 (Smithsonian Institution).
The Sand Mountain cinder cones rise to the WNW in late Spring across the still partially frozen surface of Big Lake. South (left) and North Sand Mountain cones are the largest of a group of 23 cinder cones along a N-S line immediately west of the Cascade crest, NW of Mount Washington. A series of young, sparsely vegetated lava flows reaching the valley of the McKenzie River originated from vents on the west side of the chain of cones and were erupted primarily during a 1000-year period from about 3000-4000 years ago.

Photo by Lee Siebert, 2000 (Smithsonian Institution).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Hildreth W E, 2007. Quaternary magmatism in the Cascades--geologic perpectives. U S Geol Surv Prof Pap, 1744: 1-125.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Sherrod D R, Taylor E M, Ferns M L, Scott W E, Conrey R M, Smith G A, 2004. Geologic map of the Bend 30- x 60-minute quadrangle, central Oregon. U S Geol Surv Map , I-2683, 1:100,000 scale and 48 p text.

Taylor E M, 1968. Roadside geology, Santiam and McKenzie Pass Highways, Oregon. Oregon Dept Geol Min Ind Bull, 62: 3-34.

Taylor E M, 1981. Roadlog for central High Cascade geology, Bend, Sisters, McKenzie Pass, and Santiam Pass, Oregon. U S Geol Surv Circ, 838: 59-83.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

Volcano Types

Pyroclastic cone(s)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Basalt / Picro-Basalt
Andesite / Basaltic Andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
89
89
1,574
519,291

Affiliated Databases

Large Eruptions of Sand Mountain Field Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.