Wright & Troxel

A learning tool

All right, here’s the whole story. No jargon, no technical formatting, just the history of how Lauren Wright and Bennie Troxel shaped our understanding of Death Valley, Tecopa, and the southern Mojave region.

Eagle Mountain

Lauren Wright and Bennie Troxel spent their lives in the desert. Starting in the early 1950s, they mapped the roughest country in Death Valley and beyond. What others called chaos, they patiently untangled, rock by rock. Over the years they became two of the most trusted voices in Basin and Range geology, known for their steady field habits, clean maps, and deep respect for what the land itself could tell them.

They began in Death Valley, working through the twisted terrain east of Badwater and Furnace Creek. There, scattered fault blocks looked like a puzzle someone had shaken apart. Wright and Troxel figured out that this “Amargosa Chaos” wasn’t random at all. It was the result of the crust stretching and tearing at low angles, lifting old rocks and dropping young ones. Their maps from the 1960s and 70s showed that the Valley wasn’t just a crack in the earth, but part of a much larger system in which the crust itself was thinning.

They studied the Furnace Creek and Death Valley fault zones and showed that the sideways, or strike-slip, motion wasn’t as massive as some believed. The land was moving both sideways and downward — sliding, stretching, and rotating all at once. Their careful work stopped wild speculation and grounded future studies in what could actually be seen in the rocks.

Later, when the field began to recognize “detachment faults” — those broad, low-angle breaks deep in the crust — Wright and Troxel were already there. They had mapped them years before anyone had a name for them. Their diagrams of tilted mountain blocks, uplifted footwalls, and sinking basins became the foundation for how geologists now picture the Basin and Range province.

Their influence spread southward, into the Tecopa and Shoshone area. Tecopa Basin, once thought of as just a dried-up lake, became under their framework a living tectonic basin — a place still moving, still changing. The basin sits between the Resting Spring Range on the east and the Nopah Range on the west, both tilted blocks bounded by faults. Wright and Troxel’s regional mapping explained how those ranges rose and the basin sank, all part of the same crustal stretching that shaped Death Valley.

The Resting Spring Range, they showed, is a footwall block lifted on a west-dipping detachment fault. That fault likely channels the hot water that feeds Tecopa’s springs. Across the basin, the Nopah Range tilts the other way, dropping the valley floor between them. The lake beds and alluvial fans that fill the basin record every stage of that movement. Their approach — always linking sediments, structure, and landscape — became the standard way of reading desert basins.

Following their line of thought south, the fault belt continues through Sperry Wash to the Kingston Range. There the crust was pulled so thin that deep rocks rose to the surface. Later researchers would prove the Kingston Range to be a metamorphic core complex, but it was Wright and Troxel’s earlier insight into Death Valley’s structure that pointed the way. They showed that the same forces that opened Death Valley also lifted the Kingston Range and dropped the Tecopa Basin between them.

At the southern edge of this chain lies the Avawatz Mountains, a natural hinge between the stretching Basin and Range and the sliding Mojave block. Wright and Troxel understood this as the turning point — where extension gives way to sideways shear. The Garlock Fault lies just to the south, a great east-west fracture that shifts motion from one style to another. They were among the first to argue that these systems are connected, not separate. The Garlock doesn’t stop Death Valley; it redirects it.

South of the Avawatz, the story continues through Soda and Silver Lakes, the broad dry basins near Baker. These, too, line up along the same fault trend. The Mojave River, flowing northward from the mountains through Barstow, traces that same old scar in the crust. The river’s course isn’t random — it follows a tectonic path carved long before any water ran through it. Every terrace, canyon, and dry lake along its route echoes the same pattern Wright and Troxel mapped farther north.

By the time the river reaches Afton Canyon and the dry sinks of Cronese and Soda Lake, it’s running through the tail end of their structural corridor. The ground here still moves, slowly and quietly, along the Lenwood, Lockhart, and Helendale faults. These smaller strands pick up the motion of the Garlock and pass it westward toward the San Andreas. The Mojave River flows right through the middle of it all — a living reminder of how deep-seated tectonics shape even the surface flow of water.

Wright and Troxel’s gift was not just their data but their way of seeing. They treated the desert as a single, connected organism — every basin, every fault, every dry lake part of the same long rhythm of motion. Where others saw disjointed ranges, they saw a story of continuous transformation, stretching from Furnace Creek to Barstow and beyond.

Their maps still hang in field camps and classrooms, and the Geological Society of America’s Wright–Troxel Award continues to support students studying these same basins. The accuracy of modern GPS and seismic work has only confirmed what they drew by hand half a century ago.

In the end, their legacy is both scientific and human. They showed that patient fieldwork, careful observation, and respect for the land can turn confusion into clarity. Thanks to them, the Mojave and Death Valley are no longer a tangle of broken hills but a single, coherent landscape — one long story written in the language of stone.

As a Play

You could think of the Mojave Desert as a grand Broadway production—ancient, dramatic, and full of subtle choreography that has played out for millions of years.

view from walker pass

The stage is the geology: immense backdrops of folded mountains, tilted strata, and fault lines painted by time. Volcanic cones serve as spotlight towers, alluvial fans sweep like curtains drawn across the basin floor, and the Mojave River cuts a wandering path like a traveling stagehand moving props between acts.

The set is built from plants, rocks, and the occasional weathered structure. Joshua trees rise like eccentric stage pieces, each with its own pose under the lights. Creosote bushes fill in the ensemble—reliable, understated performers who know every cue. Abandoned mining cabins, ghost towns, and derelict rail ties serve as the props and scenery from earlier acts, remnants left between scenes of prosperity and decline.

The lighting crew is the sun, directing each scene with precision—blinding spotlights at noon, warm amber tones at dusk, and moonlit silver rehearsals after dark. The wind adds the soundtrack, whispering through canyons or howling like a restless audience.

The actors? Coyotes, bighorn sheep, and lizards—all improvising within a script written by climate and time. Even the rain, when it shows up, steals the scene with a brief but powerful soliloquy, transforming everything for one fleeting act before bowing out again for months, sometimes years.

Every performance is different, but the play never closes. The Mojave’s production runs continuously, with geology always holding center stage and life finding its cues wherever it can.

Geologic Diversity

When someone mentions they are a geologist, it’s easy to assume that all geologists do the same thing. However, geology is a diverse and multifaceted field, encompassing a wide range of specialties. Each geologist may focus on different aspects of the Earth’s structure, materials, processes, and history. Here’s a more detailed look at the various types of geology and the distinct roles that geologists might have:

Types of Geology

  1. Structural Geology: Geologists in this field study the architecture and processes responsible for the deformation of the Earth’s crust. They analyze faults, folds, and rock formations to understand tectonic movements and stress patterns.
  2. Petrology: Petrologists examine the origin, composition, and structure of rocks. They specialize in:
    • Igneous Petrology: Focuses on rocks formed from magma or lava.
    • Sedimentary Petrology: Studies rocks formed by the accumulation of sediments.
    • Metamorphic Petrology: Investigates rocks transformed by heat and pressure.
  3. Mineralogy: Mineralogists study minerals, including their structure, properties, classification, and distribution. They identify and analyze mineral compositions in various geological contexts.
  4. Geochemistry: Geochemists explore the chemical composition of Earth materials and the chemical processes occurring within and on the Earth’s surface. They study element cycles and mineral interactions.
  5. Geomorphology: Geomorphologists study landforms and the processes that shape them. They analyze erosion, weathering, and sediment deposition to understand landscape evolution.
  6. Sedimentology: Sedimentologists focus on sediments and sedimentary rocks, including their formation, transport, and deposition. They study sedimentary environments like rivers, lakes, and oceans.
  7. Paleontology: Paleontologists study fossils and ancient life forms to understand the history of life on Earth. They analyze fossil records to reconstruct past ecosystems and evolutionary trends.
  8. Volcanology: Volcanologists study volcanoes, volcanic processes, and volcanic rocks. They monitor volcanic activity and assess eruption risks.
  9. Seismology: Seismologists study earthquakes and the propagation of seismic waves through the Earth. They analyze seismic data to understand earthquake mechanics and predict future events.
  10. Geophysics: Geophysicists use physical methods to study the Earth’s interior and its physical properties. They specialize in:
    • Seismic Geophysics: Uses seismic waves to map the Earth’s interior.
    • Magnetic Geophysics: Studies the Earth’s magnetic field and anomalies.
    • Gravitational Geophysics: Examines variations in the Earth’s gravitational field.
  11. Hydrogeology: Hydrogeologists study groundwater, its distribution, movement, and quality. They analyze aquifers and manage water resources.
  12. Engineering Geology: Engineering geologists apply geological knowledge to construction and environmental management engineering practices. They assess ground stability and risks for infrastructure projects.
  13. Environmental Geology: Environmental geologists focus on human interaction and the geological environment. They address natural hazards and resource management to mitigate environmental impacts.
  14. Economic Geology: Economic geologists study materials for financial and industrial purposes, such as minerals, oil, and gas. They explore and develop natural resources.
  15. Planetary Geology: Planetary geologists study the geology of other celestial bodies, such as moons, planets, and asteroids. They analyze surface features and geological processes beyond Earth.

Each type of geologist brings unique expertise to their field, contributing to a comprehensive understanding of the Earth’s dynamic systems. Understanding these distinctions helps us appreciate geologists’ specialized skills and knowledge of various challenges and projects.

Summary

Geology is a diverse field with various specialties. Structural geologists study Earth’s crust deformation, while petrologists focus on rock origins and types. Mineralogists analyze minerals, and geochemists explore Earth’s chemical processes. Geomorphologists study landforms, sedimentologists examine sediments, and paleontologists investigate fossils. Volcanologists monitor volcanic activity, seismologists study earthquakes, and geophysicists use physical methods to probe Earth’s interior. Hydrogeologists focus on groundwater, engineering geologists apply geology to construction, and environmental geologists manage natural hazards. Economic geologists explore resources like minerals and oil, and planetary geologists study celestial bodies. Each specialty offers unique insights into Earth’s processes and history.

Rainbow Basin Geology

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Rainbow Basin

Rainbow Basin is a geological formation in the Mojave Desert of California. It is known for its unique and colorful rock formations, which provide valuable insights into the region’s geological history. Here are some key aspects of the geology of Rainbow Basin:

  1. Sedimentary Rocks: Rainbow Basin primarily comprises sedimentary rocks accumulated over millions of years. These rocks include sandstones, shales, and mudstones. The different layers of sedimentary rocks represent different periods of geological history.
  2. Fossilized Marine Life: Within the sedimentary rocks of Rainbow Basin, fossils of marine life from the Miocene epoch (approximately 15-20 million years ago) have been found. These fossils include shells, bones, and other remnants of ancient sea creatures. This suggests that a shallow sea once covered the area.
  3. Faulting and Uplift: The geology of Rainbow Basin has been influenced by tectonic forces. The region is situated near the intersection of several fault lines, including the Garlock Fault. These fault movements have caused the uplift of the rocks, exposing them to erosion and creating the unique landscape seen today.
  4. Erosion and Weathering: Over time, erosion and weathering have shaped the colorful rock formations in Rainbow Basin. These processes have created intricate patterns and exposed layers of colored sediments, giving the area its name.
  5. Geological Time Scale: The rocks at Rainbow Basin span a significant portion of the geological time scale, providing geologists with valuable information about the changing environments and life forms that existed in the area millions of years ago.
  6. Geological Tours: Rainbow Basin is a popular destination for geological enthusiasts and tourists interested in its unique geology. There are guided tours and interpretive exhibits that provide insights into the geological history of the area.
Rainbow Basin photo
Rainbow Basin, Barstow, Ca.

In summary, Rainbow Basin is a geological wonder in the Mojave Desert, characterized by its sedimentary rocks, fossils, faulting, erosion, and vibrant colors. It offers a glimpse into the geological history of California and the forces that have shaped its landscape over millions of years.

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Mojave Desert Geology

Introduction:

Ryan Mountain, Joshua Tree National Park

The Mojave Desert, located in the southwestern United States, is known for its vast arid landscape and unique geological formations. Let us now look at Mojave Desert geology. We will explore its history, distinctive landforms, and the forces that have shaped this remarkable desert ecosystem.

Ancient History:

Afton Canyon, Mojave River

The geological history of the Mojave Desert dates back millions of years. It was formed through a complex interplay of tectonic forces, erosion, and climatic changes. The Mojave Desert is part of the Basin and Range Province, characterized by alternating mountain ranges and valleys. Over time, these forces have sculpted the desert’s diverse topography, creating a mesmerizing tapestry of geological wonders.

Distinctive Landforms:

Kelso Dunes, Mojave National Preserve

The Mojave Desert is home to many distinctive landforms that capture geologists’ and nature enthusiasts’ imaginations. One such feature is the Mojave River, which runs through the heart of the desert, shaping its landscape and supporting its own ecosystem. Another notable landform is the Kelso Dunes, towering sand dunes that shift and change with the wind, creating an ever-changing desert scene.

Example of faulting and jointing in granite. Geology Tour Road #6, Joshua Tree National Park
Geology Tour Road stop #6, Joshua Tree National Park

Joshua Tree National Park, located within the Mojave Desert, is renowned for its iconic Joshua trees, which dot the barren landscape. These trees are adapted to the harsh desert environment and symbolize resilience in the face of adversity. The park also boasts mesmerizing rock formations, such as Hidden Valley and Jumbo Rocks, which showcase the desert’s ancient geological past.

Forces of Shaping:

Rainbow Basin photo
Rainbow Basin, Barstow, Ca.

Several key forces have shaped the Mojave Desert’s geological landscape. The San Andreas Fault, a major tectonic boundary, runs through the region, causing periodic earthquakes and contributing to the uplift of mountain ranges. Erosion, primarily driven by wind and water, has significantly sculpted the desert’s landforms, creating deep canyons, rugged cliffs, and intricate rock formations.

Amargosa River
Amargosa River

The climate also shapes the Mojave Desert’s geology. The region experiences extreme temperature fluctuations, with scorching hot summers and chilly winters. These temperature extremes and sporadic rainfall contribute to rock weathering and erosion and the formation of unique geological features.

Conclusion:

West Fork, Mojave River
West Fork, Mojave River

The Mojave Desert stands as a testament to the immense power of geological forces and the intricate beauty they can create. From its ancient history to its distinctive landforms, the desert offers a glimpse into the Earth’s ever-evolving landscape. As we explore the Mojave Desert’s geology, we gain a deeper appreciation for the natural wonders that surround us and the forces that have shaped them over millions of years.

Geology List

Geology Thumbnail Index

Mojave Desert Geology

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California’s geomorphic provinces are naturally defined geologic regions that … Earthquakes & Faults · San Andreas Fault. Summary of the earthquake fault …

Cajon Pass Geology

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Heteromyid rodents from Miocene faunas of the Mojave Desert, Southern California. Natural History Museum of Los Angeles County. Science Series 41; p. 213-236.

Geology of Red Rock Canyon

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Red Rock Canyon California State Park. The geologic story of Red Rock Canyon is told by its …

Death Valley Geology

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California/Nevada Death Valley Regional Geology. Field Trip Guide. Walk Through Time. Badwater with Telescope …

Geology of Mojave Preserve

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Mesozoic Rocks. Source – NPS, Cinder cones national natural landmark. Kelso Dunes, Mojave Preserve, Eastern Mojave Desert Banshee …

The Mojave Desert – Shaping the Classic American Desert

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The area of most dramatic relief is around Death Valley, California, where the elevation drops from 3,400 m above sea level at Telescope Peak to 88 m below sea …

Desert Sand Dune Geology

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The Geology of Sand Dunes. While one-quarter to one-third of the world’s deserts are covered with sand, little research has taken …

Mojave Preserve Geology – Landforms

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Desert landscape and surface processes study, Mojave National Preserve.

Hole in the Wall – Mojave Preserve

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Mojave Preserve – Geology. Hole-in-the-Wall. Hidden violence. Visitors to Mojave National Preserve are fascinated by the brightly colored, …

The Mojave River and Associated Lakes – Mojave Desert Geology

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Desert landscape and surface processes study, Mojave National Preserve.

Geology – Death Valley Rock Samples – Mojave Desert

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A rock formation is a body of rock of a considerable extent with distinctive characteristics that allow geologists to map, describe, and name it. The sample rocks …

Geology of the Death Valley Region

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The three sites in this area lie in the extreme southeast corner of Death Valley National Park immediately west of California Highway 127 which provides the …

Introduction to Geology of the Mojave Desert

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Far from being static, the geology of Earth is dynamic, in constant motion and change. The crust is a puzzle made up of tectonic plates, shifting against …

Geology of Joshua Tree

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Mojave Desert Geology: Joshua Tree National Park – Nature & Environment. Geology of Joshua Tree. Geologic Displays. The park encompasses some of the most …

Earthquake Faults: Mojave Desert Geology

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Geology: Earthquakes & Faults: California straddles the juncture of two great crustal plates: the Pacific plate and the North American plate.

Desert Sand Dune Geology

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Wind-induced Sand Movement. Photo of a dust devil on Soda Lake in the Mojave Preserve transporting sand. Individual sand grains are moved under the force of the …

Rock Formations – Mojave Desert

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Trona Pinnacles. This eerie, fantastic landscape is one of the most unique geological features in the California desert. These … Vasquez Rocks. These towering …

Desert Landforms & Surface Processes

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Historic weather data for the Eastern Mojave Desert is relatively scarce because there is no significant … Geologic History. The oldest rocks exposed in the …

Geology of Mono Lake

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This ongoing process has created the majestic contrast of a desert lake bordered by high mountain peaks. As the western floor of the Mono Basin slipped …

Geology Tour Road

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Map, photos and virtual tour of the Geology Tour Road in Joshua Tree National Park.

Introduction to the Arch Rock Geology tour

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Geology tour of White Tank Arch Rock in Joshua Tree National Park.

The Geology of the Mojave Desert

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The earliest rock, related to the metamorphic gneiss and schist at the bottom of the Grand Canyon, has little exposure in the Mojave, but can be seen at Saddle …

Magma On The Move: Geology of the Mojave Desert

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Along with the faulting, volcanic activity increased across the landscape. Igneous rock is derived from molten layers of magma beneath the Earth’s crust. Under …

Changing Climates and Ancient Lakes Mojave Desert

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Information was derived from articles within Enzel, Wells, and Lancaster (2003); [Geological Society of America Special Paper 268].

General Geologic History – Mojave Preserve – California Mojave

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Desert landscape and surface processes study, Mojave National Preserve.

Geology Road – Joshua Tree National Park

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Driving tour of Joshua Tree geology

Mitchell Caverns

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The Providence Mountains caves, like most limestone caves in other parts of the world, seem to have had a two-stage history. Most geologists who have studied …

Volcanic Rocks and Associated Landforms

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Cinder Cones and Lava Flows National Natural Landmark Area. Volcanic eruptions have occurred many times throughout the Mojave National Preserve in the geologic …

Badwater – Death Valley Geology

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Some of the minerals left behind by earlier Death Valley lakes dissolved in the shallow water, creating a briny solution. The Desert Returns. The wet times didn’t …

Geology Red Rock National Conservation Area

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For much of the past 600 million years, the land that is now Red Rock Canyon NCA was the bottom of a deep ocean basin and the western coast of North America was …

Mosaic Canyon – Death Valley Geology

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Smooth, polished marble walls enclose the trail as it follows the canyon’s sinuous curves. The canyon follows faults that formed when the rocky crust of the …