earth science

Lava Beds National Monument

Lava Beds National Monument is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Lava Beds National Monument rather than just read about it. In short: Lava Beds National Monument is located in northeastern California, in Siskiyou and Modoc counties. The monument lies on the northeastern flank of Medicine Lake Volcano, which is the largest volcano by area in the Cascade Range.

Key takeaways

Lava Beds National Monument belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Lava Beds National Monument to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lava Beds National Monument from memory before moving on to harder problems.

Reference excerpt

Lava Beds National Monument is located in northeastern California, in Siskiyou and Modoc counties. The monument lies on the northeastern flank of Medicine Lake Volcano, which is the largest volcano by area in the Cascade Range. The region in and around Lava Beds National Monument lies at the junction of the Sierra-Klamath, Cascade, and Great Basin physiographic provinces. The monument was established as a national monument on November 21, 1925, and includes more than 46,000 acres (190 km2). Lava Beds National Monument has numerous lava tubes, with 27 having marked entrances and developed trails for public access and exploration. The monument also offers trails through the high Great Basin xeric shrubland desert landscape and the volcanic field. In 1872 and 1873, the area was the site of the Modoc War, involving a band led by Kintpuash (also known as Captain Jack). The area of Captain Jack's Stronghold was named in his honor.

Geologic formations Lava Beds National Monument is geologically significant because of its wide variety of volcanic formations, including lava tubes, fumaroles, cinder cones, spatter cones, pit craters, hornitos, maars, lava flows, and volcanic fields. Volcanic eruptions on the Medicine Lake shield volcano have created a rugged landscape punctuated by these many landforms of volcanism.

Cones

Cinder cones are formed when magma is under great pressure. It is released in a fountain of lava, blown into the air from a central vent. The lava cools as it falls, forming cinders that pile up around the vent. When the pressure has been relieved, the rest of the lava flows from the base of the cone. Cinder cones are typically monogenetic. The cinder cones of Hippo Butte, Three Sisters, Juniper Butte, and Crescent Butte are all older than the Mammoth and Modoc Crater flows, more than 30,000–40,000 years old. Eagle Nest Butte and Bearpaw Butte are 114,000 years old. The Schonchin Butte cinder cone and the andesitic flow from its base were formed around 62,000 years ago. The flow that formed Valentine Cave erupted 10,850 years ago. An eruption that formed The Castles is younger than the Mammoth Crater flows. Even younger were eruptions from Fleener Chimneys, such as the Devil's Homestead flow, 10,500 years ago, and Black Crater 3,025 years ago. About 1,110 years ago, plus or minus 60 years, the Callahan flow was produced by an eruption from Cinder Butte. Though Cinder Butte is just outside the boundary of the monument, the Callahan flow is in Lava Beds and is the youngest flow in the monument. Spatter cones are built out of thicker lava. The lava is thrown out of the vent and builds, layer by layer, a chimney surrounding the vent. Fleener Chimneys and Black Crater are examples of spatter cones.

Lava flows

Roughly ninety percent of the lava in the Lava Beds Monument is basaltic. There are primarily two kinds of basaltic lava flows: pahoehoe and ʻaʻā. Pahoehoe is smooth, often ropy and is the most common type of lava in Lava Beds. ʻAʻā is formed when pahoehoe cools and loses some of its gases. ʻAʻā is rough, sharp, and jagged; an excellent example is the Devil's Homestead lava flow, which originated at Fleener Chimneys. Most of the rest of the lava in the monument is andesitic. Pumice, a type of rhyolitic lava, also is found covering the monument; this rained down around 900 years ago during the eruption of Glass Mountain. The flows from Mammoth and Modoc Craters comprise about two-thirds of the lava in the monument. Over 30 separate lava flows located in the park range in age from 2,000,000 years BP to 1,110 years BP. Some of the major lava flows within Lava Beds National Monument include the Callahan Flow; Schonchin Flow; Mammoth Crater Flow; Modoc Crater Flow; and Devil's Homestead Flow.

Lava fields Gillem Bluff, a fault scarp, was created as the region stretched and a block of earth dropped down along this fault (see Basin and Range Province). The tuff layer on top of Gillem Bluff is 2,000,000 years old, indicating the rock layers beneath are even older. The oldest lava flow from the Medicine Lake Volcano within the monument is the Basalt of Hovey Point, near Captain Jack's Stronghold, which is 450,000 years old. Petroglyph Point was created about 275,000 years ago when cinders erupted through the shallow water of Tule Lake; violent explosions of ash and steam formed layers upon layers of tuff. The caldera is thought to have formed by subsidence, during which basalt and andesite were erupted up on the slopes.

Lava tubes

Lava flows dated to about 30,000–40,000 years ago formed most of the lava tubes in the monument. As the hot basaltic lava flowed downhill, the top cooled and crusted over, insulating the rest of the lava and forming lava tubes. Lavacicles on the ceiling of a lava tube were produced as the level of lava in the tube retreated and the viscous lava on the ceiling dripped as it cooled. Dripstone was created when lava splashed on the inside walls of the tubes. The leaching of minerals from pumice gravel, soils, and overlying rock provides for deposition of secondary speleothems in lava tubes. Lava Beds National Monument has the largest concentration of lava tubes in North America. One has electrical lighting; the others are illuminated by ceiling collapse portals or require flashlights, available on loan. Notable examples in the park include Catacombs Cave, Merrill Cave, Mushpot Cave, and Valentine Cave.

Recent activity A series of small earthquakes in late 1988 has been attributed to subsidence in the caldera. North-northeast trending ground cracks, as well as north-northeast trending vent series show relationships between tectonism and volcanism. One notable ground crack, the Big Crack, extends along the northeastern boundary of the monument.

Climate The high elevation, semi-arid desert environment of Lava Beds National Monument receives an average of 14.22 in (36 cm) of annual precipitation, including 43.2 in (110 cm) of snowfall. The climate is characterized by warm, dry summers and cold, moderately snowy winters. The monthly daily average temperature ranges from 31.8 °F (−0.1 °C) in December to 68.92 °F (20.5 °C) in July; there are an average of 23.8 days with 90 °F (32 °C)+ highs annually, and 8.4 days where the high does not rise above freezing. The average window for freezing temperatures is September 20 thru June 6.

Flora and fauna

Flora

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Illustrations

Worked examples

Example 1 — a first encounter with Lava Beds National Monument

Start with the simplest possible case. Write down what Lava Beds National Monument claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Lava Beds National Monument before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Lava Beds National Monument ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Lava Beds National Monument

In research: Lava Beds National Monument appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Lava Beds National Monument in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Lava Beds National Monument is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1925 establishments in California, Archaeological sites in California, Cascade Volcanoes, so understanding it makes those chapters shorter.
In everyday life: Look for Lava Beds National Monument outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Lava Beds National Monument in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lava Beds National Monument means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Lava Beds National Monument out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lava Beds National Monument in simple terms?

Why does Lava Beds National Monument matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Lava Beds National Monument?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Lava Beds National Monument.