Member Since 1983
Brad R. Hacker
Professor Emeritus, University of California Santa Barbara
AGU Research
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The average composition of lower continental crust is intermediate, not mafic
AGU 2024
volcanology, geochemistry and petrology | 11 december 2024
Peter B. Kelemen, Mark D. Behn, Bradley R. Hacker
In this invited presentation and a paper in press (Kelemen, Behn & Hacker, Treatise on Geochemistry, 3rd Edition, "Average Composition & Genes...
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Average composition & genesis of the continental lower crust: Density sorting beneath arcs and continental collision zones
THE FATE OF THE LITHOSPHERE DURING CONTINENTAL COLLISION: SLAB DEFORMATION, LITHOSPHERIC REMOVAL, AND TECTONIC SEGMENTATION IN ACTIVE OROGENIC SYSTEMS III POSTER
tectonophysics | 14 december 2023
Peter B. Kelemen, Mark D. Behn, Bradley R. Hacker
We combine area- & volume-weighted average seismic wave speeds of lower continental crust (LCC) with thermodynamic calculations of mineral proport...
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Protracted Subduction of the European Hyperextended Margin Revealed by Rutile U‐Pb Geochronology Across the Dora‐Maira Massif (Western Alps)
TECTONICS
04 april 2022
Guillaume Bonnet, Christian Chopin, Michele Locate...
The Dora‐Maira massif is an archetypal nappe stack of subducted and exhumed upper crust. Slices of continental crust experienced metamorphism...
Assembly and Tectonic Evolution of Continental Lower Crust: Monazite Petrochronology of the Ivrea‐Verbano Zone (Val Strona di Omegna)
TECTONICS
16 march 2022
Damaris C. Wyatt, Andrew Smye, Joshua M. Garber, B...
Metasediments are common constituents of exhumed lower‐to‐mid‐crustal granulite terranes; understanding their emplacement is sign...
Relamination and Crustal Refining
NORMAN L. BOWEN AWARD LECTURE I
volcanology, geochemistry and petrology | 15 december 2021
Bradley R. Hacker
Most immature crust must be refined to attain the composition of mature continental crust. This refining may take the form of weathering, delamination...
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U–Pb Dates From Dynamically Recrystallized Titanite Directly Constrain Timing of Crystal-Plastic Deformation
ADVANCES AND APPLICATIONS OF IN SITU PETROCHRONOLOGY AND THERMOCHRONOLOGY I ORAL
volcanology, geochemistry and petrology | 14 december 2021
Amy C. Moser, Bradley R. Hacker, Tarryn K. Cawood,...
Directly dating high-temperature deformation is important for constraining the timing and duration of numerous geologic processes, yet a widely applic...
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Dating Continental Subduction Beneath the Samail Ophiolite: Garnet, Zircon, and Rutile Petrochronology of the As Sifah Eclogites, NE Oman
JOURNAL OF GEOPHYSICAL RESEARCH: SOLID EARTH
04 december 2021
Joshua M. Garber, Matthew E. Rioux, Michael P. Sea...
Studies of the high‐pressure (HP) As Sifah eclogites in the NE Saih Hatat Window, Oman, have used different combinations of radiometric datin...
Interpreting titanite U–Pb dates and Zr thermometry in high-grade rocks: Empirical estimates of elemental diffusivities
ADDITIONAL NOBLE GAS AND SOLID STATE THERMOCHRONOMETERS - PART 1: ORAL PRESENTATIONS
general program | 14 september 2021
Robert M. Holder, Bradley R. Hacker, Gareth Seward...
Length scales of compositional heterogeneity in titanite from 750 to 1000 °C metamorphic rocks from southern Madagascar were measured to provide empir...
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