John P. Platt is a professor and structural geologist at the

University of Southern California The University of Southern California (USC, SC, or Southern Cal) is a Private university, private research university in Los Angeles, California, United States. Founded in 1880 by Robert M. Widney, it is the oldest private research university in ...

. His research centers on deformation processes within Earth's crust and

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time ...

, focusing on convergent plate margins and collisional orogens through the applications of geophysical methods and mechanical modeling.

Academic Career

Platt earned a BA in Geology from

Oxford University The University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the second-oldest continuously operating u ...

followed by a PhD from the

University of California, Santa Barbara The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a Public university, public Land-grant university, land-grant research university in Santa Barbara County, California, United States. Tracing its roots back to 1891 as an ...

. Platt's early academic career included lectureships at City University of Amsterdam and

Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ...

, where he was a tutorial fellow at St. Anne's College. Following that, Platt was the Yates-Goldsmid Professor, at the

University College London University College London (Trade name, branded as UCL) is a Public university, public research university in London, England. It is a Member institutions of the University of London, member institution of the Federal university, federal Uni ...

, before moving to the

. John P. Platt continues to collaborate with former students including Whitney Behr.

Awards

* Fellow of the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hi ...

* 2023 Career Contribution Award from the Structural Geology & Tectonics division of the

* 2018 Stephan Mueller Award from the

European Geosciences Union The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet". The organisation has headq ...

Research

Platt uses a multidisciplinary approach, combining microstructural analysis, geochronology, thermal modeling, and rheology to study the mechanics of lithospheric deformation across various geological contexts, including orogenic wedges and metamorphic core complexes like those in the Western US Cordillera and the

Betic Cordillera The Baetic System or Betic System () is one of the main systems of mountain ranges in Spain. Located in the southern and eastern Iberian Peninsula, it is also known as the Cordilleras Béticas (Baetic Mountain Ranges) or Baetic Mountains. The n ...

of Spain. His research highlights deformation processes at plate margins and the integration of field studies with mechanical and analytical modeling to describe large-scale tectonic dynamics, including the formation and exhumation of high-pressure rocks, the behavior of low-angle normal faults, and the role of extensional deformation in convergent margins.

Notable publications

Dynamics of orogenic wedges and the uplift of high-pressure metamorphic rocks: Platt explored the deformation histories of convergent orogenic wedges experiencing prograde metamorphism. He found that an orogenic wedge undergoing subduction deforms internally until gravitational forces are in equilibrium with subduction traction. Accretion at the front of the wedge induces shortening via folding, late-thrusting, and back thrusting. High pressure metamorphic rocks are uplifted through normal faults due to deep underplating. Deformation histories of orogenic wedges are complex; variations in wedge rheology, subduction rate, sediment thickness, and accretion style lead to alternating periods of internal shortening and extension. Exhumation of high-pressure rocks: a review of concepts and processes: This review discusses mechanisms of high-pressure metamorphic rock exhumation beyond thrusting or strike-slip faulting—buoyancy-driven rise of less dense rocks, extension due to surface elevation contrasts, and corner flow of low-viscosity material in subduction zones. The work concludes that a combination of mechanisms can describe the upward movement of deeply buried rocks and their emplacement in diverse tectonic settings. A naturally constrained stress profile through the middle crust in an extensional terrane: Platt and co-authors construct a stress profile of the Whipple Mountains metamorphic core complex through exhumed middle-crustal rocks, applying methods of paleopiezometry, Ti-in-quartz thermobarometry, and 2-D thermal modeling. The publication provides insight into crustal strength, fault friction and regional stress conditions during Miocene extension. Extensional collapse of thickened continental lithosphere: A working hypothesis for the Alboran and Gibraltar arc: The article explains a hypothesis on the extensional collapse of thickened continental lithosphere. It suggests that the lithosphere in the Alboran Sea and Gibraltar arc underwent significant thickening due to tectonic forces, followed by extensional collapse. This process may have been crucial to the formation of these geological features. Extensional structures in anisotropic rocks: This article shows the development of extensional structures in anisotropic rocks. It explains the roles of mineral alignment and structural heterogeneities in controlling the formation of features like faults, fractures, and shear zones under extensional stress. The authors show how anisotropy affects the evolution of extensional structures.

References

American geologists Year of birth missing (living people) Living people {{improve categories, date=March 2025 University of Southern California faculty University of California, Santa Barbara alumni Fellows of the Geological Society of America