8: Basin and Range
- Page ID
- 20342
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Introduction to the Basin and Range
The Basin and Range Province is situated in easternmost California (Figure \(\PageIndex{1}\)) and is probably one of the most important natural geologic laboratories in the world. Because of its lack of vegetation and the long span of geologic time that is represented in this region, scientists from all over the world have used this area to formulate and test their geologic hypotheses. Important studies emerging from this region have produced tectonic reconstructions of the western U.S., proposals of an ancient “snowball earth,” and a new understanding of the ways Earth’s crust behaves during mountain building! This region is also the home of Death Valley National Park and the focal point of water rights and land use controversies that have been evolving for centuries.
The geologic story of the Basin and Range is a long one, going back to the Middle Proterozoic Eon. Its most recent history, however, is one of continental rifting, which has produced the distinctive “basin and range” structures for which this region is named, along with volcanism caused by crustal thinning. Widespread normal faulting caused by this rifting has exposed old rocks (including some of the oldest found in California) in uplifted footwall blocks, making it possible to study the earlier history of this region. Geologic activity also continues today: ongoing seismic and magmatic activity present not only serious hazards in the region, but also important geothermal resources and create a dynamic landscape with a lot to interest geologists.
There is plenty of geology to discuss in this region and it would be impossible to complete this study in a one-semester course. This chapter will, instead, aim to provide an introduction to a few key aspects of the region and lay the groundwork for future study and examination as your interests guide you. In particular, our focus will be on the concept of continental rifting, illustrated with examples from the Death Valley and Owens Valley regions, including some of the hazards and benefits resulting from this rift environment. The chapter will conclude with a discussion of some of the bedrock geology that was exposed by this rifting and the insights it provides about the geologic past.
By the end of this chapter, you should be able to:
- Locate the Basin and Range Province on a map of California.
- Describe the primary geomorphic features in the Basin and Range Province.
- Recall the major geologic units in this province as presented on a simplified map of California.
- Explain the origin of the “basin and range” structures in this geomorphic province.
- Outline the evidence for ongoing seismic hazard in this geomorphic province.
- Summarize the geologic evidence for continental rifting in the Basin and Range Province.
- Explain the origin of rift-related volcanic features found in this region and their associated hazards and benefits.
- Summarize the evidence for Late Proterozoic rifting and glaciation in this region.
- 8.1: Regional Extent and Overview of the Basin and Range
- This page discusses the Basin and Range Province in California, highlighting its unique geological features, elevation extremes from Mt. Whitney to Badwater Basin, and the influence of the Sierra Nevada's rain shadow. It emphasizes Death Valley National Park's significant geology and human history, particularly its ties to the Timbisha Shoshone tribe.
- 8.2: Rifting in the Basin and Range
- This page discusses continental rifting, a process driven by tensional stress that results in crustal extension and thinning, crucial to the Wilson Cycle and the breakup of supercontinents like Pangea. It outlines the stages of rifting, such as faulting, basin formation, and volcanic activity, with a focus on the distinctive rifting style in the Basin and Range Province due to tectonic interactions.
- 8.3: Rift-Related Faulting in Eastern California
- This page explores geological structures in the Basin and Range, focusing on normal faults that create horst-and-graben and half-graben formations. It highlights the role of oblique slip faults in accommodating tectonic activity, noting significant seismic events and the region's ongoing seismic risks.
- 8.4: Sedimentary Products of Rifting in the Basin and Range
- This page covers sedimentation in rift basins, detailing how clastic debris from eroding footwall blocks informs basin formation history and the characteristics of sediment depending on transport distance. It also discusses sediment patterns in horsts and grabens, leading to saline lake formations like Mono Lake and Owens Lake, emphasizing environmental impacts from water diversion.
- 8.5: Rift-Related Volcanism in Eastern California
- This page explores the connection between crustal thinning and volcanism in the Basin and Range region, detailing how normal faulting facilitates magma formation. It emphasizes the area's notable volcanic features, particularly the Bishop Tuff, and associated hazards from explosive eruptions and pyroclastic flows.
- 8.6: The Oldest Rocks in the Basin and Range
- This page explores the geological setting before rifting in the Basin and Range Province, characterized by a passive continental margin and sedimentary records from the ancient Paleozoic ocean. It introduces the Pahrump Group and connections to rifting and Neoproterozoic glaciations.
- 8.7: Chapter Summary
- This page presents a concise summary of the highlights of each section in this chapter on the Basin and Range Province.
- 8.8: Detailed Figure Descriptions
- Descriptions of complex images within this chapter, for users who have difficulty seeing and interpreting images.
Thumbnail: "Basin and Range Province" is licensed under CC BY-NC 4.0 by Allison Jones.