scholarly journals Hillslopes Record the Growth and Decay of Landscapes

Science ◽  
2013 ◽  
Vol 341 (6148) ◽  
pp. 868-871 ◽  
Author(s):  
Martin D. Hurst ◽  
Simon M. Mudd ◽  
Mikael Attal ◽  
George Hilley
Keyword(s):  
United States ◽  
Numerical Modeling ◽  
Nonlinear Diffusion ◽  
Vertical Displacement ◽  
Back Pressure ◽  
Erosion Rates ◽  
Pressure Ridge ◽  
Tectonically Active ◽  
History Of ◽  
Uplift History

Earth's surface archives the combined history of tectonics and erosion, which tend to roughen landscapes, and sediment transport and deposition, which smooth them. We analyzed hillslope morphology in the tectonically active Dragon’s Back Pressure Ridge in California, United States, to assess whether tectonic uplift history can be reconstructed using measurable attributes of hillslope features within landscapes. Hilltop curvature and hillslope relief mirror measured rates of vertical displacement caused by tectonic forcing, and their relationships are consistent with those expected when idealizing hillslope transport as a nonlinear diffusion process. Hilltop curvature lags behind relief in its response to changing erosion rates, allowing growing landscapes to be distinguished from decaying landscapes. Numerical modeling demonstrates that hillslope morphology may be used to infer changes in tectonic rates.

scholarly journals Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic10Be erosion rates and river longitudinal profile analysis

Tectonics ◽  
2012 ◽  
Vol 31 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Valerio Olivetti ◽  
Andrew J. Cyr ◽  
Paola Molin ◽  
Claudio Faccenna ◽  
Darryl E. Granger
Keyword(s):  
Southern Italy ◽  
Profile Analysis ◽  
Longitudinal Profile ◽  
Erosion Rates ◽  
History Of ◽  
Uplift History

Diapiric relamination of the Orocopia Schist (southwestern U.S.) during low-angle subduction

Geology ◽  
2021 ◽  
Author(s):  
James B. Chapman
Keyword(s):  
United States ◽  
Numerical Modeling ◽  
Analytical Solutions ◽  
Lower Crust ◽  
Initial Period ◽  
Mantle Lithosphere ◽  
Laramide Orogeny ◽  
History Of ◽  
Peak Metamorphism ◽  
Exhumation History

The Orocopia Schist and related schists are sediments subducted during the Laramide orogeny and are thought to have been underplated as a laterally extensive layer at the base of the crust in the southwestern United States Cordillera. This concept is hard to reconcile with the existence of continental mantle lithosphere in southeastern California and western Arizona. Analytical solutions and numerical modeling suggest that the Orocopia Schist may have ascended through the mantle lithosphere as sediment diapirs or subsolidus crustal plumes to become emplaced in the middle to lower crust. Modeled time-temperature cooling paths are consistent with the exhumation history of the Orocopia Schist and explain an initial period of rapid cooling shortly after peak metamorphism. The Orocopia Schist represents a potential example of relaminated sediment observable at the surface.

Review of A brief history of the United States.

1919 ◽  
Vol 10 (8) ◽  
pp. 414-414
Author(s):  
No authorship indicated
Keyword(s):  
United States ◽  
The United States ◽  
History Of

A History of the United States

2017 ◽  
Author(s):  
Philip Jenkins
Keyword(s):  
United States ◽  
The United States ◽  
History Of

An American Language

2018 ◽  
Author(s):  
Rosina Lozano
Keyword(s):  
United States ◽  
National Policy ◽  
The United States ◽  
Spanish Language ◽  
Spanish Speakers ◽  
Language Recognition ◽  
Political Language ◽  
Political Issue ◽  
History Of ◽  
The U.S

An American Language is a political history of the Spanish language in the United States. The nation has always been multilingual and the Spanish language in particular has remained as an important political issue into the present. After the U.S.-Mexican War, the Spanish language became a language of politics as Spanish speakers in the U.S. Southwest used it to build territorial and state governments. In the twentieth century, Spanish became a political language where speakers and those opposed to its use clashed over what Spanish's presence in the United States meant. This book recovers this story by using evidence that includes Spanish language newspapers, letters, state and territorial session laws, and federal archives to profile the struggle and resilience of Spanish speakers who advocated for their language rights as U.S. citizens. Comparing Spanish as a language of politics and as a political language across the Southwest and noncontiguous territories provides an opportunity to measure shifts in allegiance to the nation and exposes differing forms of nationalism. Language concessions and continued use of Spanish is a measure of power. Official language recognition by federal or state officials validates Spanish speakers' claims to US citizenship. The long history of policies relating to language in the United States provides a way to measure how U.S. visions of itself have shifted due to continuous migration from Latin America. Spanish-speaking U.S. citizens are crucial arbiters of Spanish language politics and their successes have broader implications on national policy and our understanding of Americans.

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