Newberry volcano, situated east of the Cascade Range, covers an area of about 1,600 km2. The low-angle basaltic to basaltic-andesite shield volcano includes more than 400 cinder cones, but has also produced major silicic eruptions associated with formation of a 6 x 8 km summit caldera containing two lakes. The earliest eruptive products (less than 0.73 Ma) consist of a sequence of ash-flow and airfall tuffs. Caldera collapse is thought to be associated with major ash deposits from about 0.5 and 0.3-0.5 Ma. These eruptions were preceded by the emplacement of numerous mafic cones and vents, and silicic lava domes and flows, many of which are aligned NNW and NNE parallel to regional fault zones. Six major eruptions from the early Holocene to about 1,300 years ago have included both basaltic lava flows from flank vents, the explosive ejection of rhyolitic pumice and pyroclastic flows, and the extrusion of obsidian flows within the caldera.
Information[]
Volcano Landform
Volcano Types
- Shield volcano
- Caldera
- Pyroclastic Cone
- Lava dome
Last Eruption: 690 AD
Recorded Eruptions
- 690 AD (VEI 4)
- 490 AD (VEI 4)
- 1450 BC
- 4450 BC
- 4690 BC
- 4770 BC
- 4860 BC
- 4960 BC
- 5070 BC (VEI 3)
- 5260 BC
- 9210 BC
Rock Types
- Andesite/Basaltic Andesite
- Dacite
- Basalt/Picro-Basalt
- Rhyolite
Gallery[]
The crater rim of Lava Butte scoria cone on the NW flank provides a view of the broad Newberry shield volcano. Many other NW flank cones and associated lava flows erupted about the same time as the Lava Butte cone and lava flow. Over the past 7,700 years Newberry has erupted both mafic and silicic lavas from flank vents and within the caldera, respectively.
The Big Obsidian Flow erupted from Newberry Caldera in Central Oregon is composed of glassy rhyolite, formed when lava rapidly cools. The flow covers 20 square kilometers of the caldera floor. Obsidian flows are never entirely glassy, but also contain large amounts of frothy pumiceous material and devitrified (crystallized) spherulites, which commonly form bands alternating with layers of glass.
As many as 400 scoria cones that dot the flanks of the massive 30 x 60 km wide Newberry shield volcano in oregon are seen in this view from Paulina Peak on the south rim of Newberry Caldera. The scoria cones at Newberry are most abundant on the north and south flanks. Many are of Pleistocene age, but cones along a rift on the NW flank and some on the south flank have erupted during the Holocene.
Newberry shield volcano covers an area of about 1,600 square kilometers about 60 km E of the crest of the Cascade Range in central Oregon. The low-angle shield volcano covers an area of 60 km in a N-S direction and 30 km E-W. More than 400 scoria cones dot the flanks of the volcano, including Lava Butte at the left center of this photo, one of many cones formed around 6,100 years ago along the NW rift zone.
Paulina Lake is the westernmost of two lakes within Newberry caldera and is seen here from Paulina Peak, the high point of the southern caldera rim. The lava flow entering the lake to the upper-right erupted about 6,400 years ago from the Central Pumice Cone. The flow split into two lobes, and the other lobe traveled into East Lake, just out of view to the right. This was one of several eruptive vents within the caldera that were active during the eruptive phase.