Diamond Craters

Photo of this volcano
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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 43.1°N
  • 118.75°W

  • 1435 m
    4707 ft

  • 322170
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports for Diamond Craters.

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The Global Volcanism Program has no Bulletin Reports available for Diamond Craters.

Geological Background

Diamond Craters volcanic field consists of a 60 sq km area of basaltic lava flows and numerous cinder cones and maars located between the SE Oregon town of Burns and Steens Mountain. A basaltic pahoehoe lava field is overlain by deposits from phreatomagmatic and strombolian eruptions that formed a late-stage central vent complex of about 20 craters and cones that densely fill a 1.1 x 1.6 km box-shaped caldera. The age of Diamond Craters is constrained to within 7320-7790 calibrated years Before Present by radiocarbon-dated floodplain deposits below the lava flows and paloemagnetic evidence (Sherrod et al., 2012). Structural doming at Diamond Craters has created a series of six overlapping topographic highs. The highest of these is known as Graben Dome; its 1435-m-high summit is cut by a NW-SE-trending graben 0.4 x 2.1 km long and 30 m deep. Lava flows on the eastern side of the volcanic field and scattered cinder cones and maars formed during the last stage of activity.

Eruptive History

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
5610 BCE ± 470 years Unknown Confirmed 4 Radiocarbon (corrected)

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.


Feature Name Feature Type Elevation Latitude Longitude
Big Bomb Crater Pyroclastic cone 1308 m
Lava Pit Crater Shield volcano 1305 m
Red Bomb Crater Pyroclastic cone 1323 m


Feature Name Feature Type Elevation Latitude Longitude
Central Crater Complex Caldera 1378 m
Diamond Pond (Malheur Maar) Maar 1286 m
Dry Maar Maar 1268 m
East Twin Crater Maar 1326 m
Keyhole Explosion Crater Crater
Malheur Maar Maar 1286 m
Nolf Crater Maar
Oval Crater Crater
West Twin Crater Maar 1326 m

Photo Gallery

Diamond Craters in SE Oregon is a 60 sq km volcanic field consisting of basaltic lava flows and numerous cones and craters. The central vent complex in this photo formed as a result of explosive eruptions from as many as 20 craters and cones. The age of the latest volcanic activity is not known precisely, but could be as young as late Pleistocene or early Holocene.

Oregon Dept. Geology and Mineral Industries photo in Green and Short (1971).
Lava flows of West Dome, one the structural highpoints of Diamond Craters, rise NE of lake-filled Malheur Maar. The shallow 2-m-deep lake occupies one of many maars (the rest of which are dry) of the Diamond Craters volcanic field. Diamond Craters consists of a 60 sq km area of basaltic lava flows, cinder cones, and maars that form a unique geologic environment in the high desert country of SE Oregon. Initial eruptions of pahoehoe lava flows were followed by magma injection that produced six structural highs of up to 120 m.

Photo by Lee Siebert, 2002 (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.

Benedict E, 2000. Diamond Craters, Oregon's geologic gem. U S Bur Land Management brochure BLM/OR/WA/GI-00/027-1122.32.

Chitwood L A, 1994. Inflated basaltic lava--examples of processes and landforms from central and southeast Oregon. Oregon Geol, 56: 11-21.

Friedman I, Peterson N, 1971. Obsidian hydration dating applied to dating of basaltic volcanic activity. Science, 172: 1028.

Green J, Short N M, 1971. Volcanic Landforms and Surface Features: a Photographic Atlas and Glossary. New York: Springer-Verlag, 519 p.

Russell J K, Nicholls J, 1987. Early crystallization history of alkali olivine basalts, Diamond Craters, Oregon. Geochim Cosmochim Acta, 51: 143-154.

Sarna-Wojcicki A M, Champion D E, Davis J O, 1983. Holocene volcanism in the conterminous United States and the role of silicic volcanic ash layers in correlation of latest Pleistocene and Holocene deposits. In: Wright H E (ed) {Late-Quaternary Environments of the United States}, Minneapolis: Univ Minnesota Press, 2: 52-77.

Sherrod D R, Champion D E, McGeehin J P, 2012. Age and duration of volcanic activity at Diamond Craters, southeastern Oregon. J Volc Geotherm Res, 247-248: 108-114.

Smith R L, Shaw H R, 1975. Igneous-related geothermal systems. U S Geol Surv Circ, 726: 58-83.

Smith R L, Shaw H R, Luedke R G, Russell S L, 1978. Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States. U S Geol Surv Open-File Rpt, 78-925: 1-25.

Smith W D, 1927. Contribution to the geology of southeastern Oregon (Steens and Pueblo Mountains). J Geol, 35: 421-440.

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

Volcano Types

Volcanic field

Tectonic Setting

Rift zone
Continental crust (> 25 km)

Rock Types

Basalt / Picro-Basalt


Within 5 km
Within 10 km
Within 30 km
Within 100 km

Affiliated Databases

Large Eruptions of Diamond Craters 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.