This study provides a global assessment of the abundance of the major oxides in the deep continental crust. The combination of geochemistry and seismology better constrains the composition of the middle and lower continental crust better than either discipline can achieve alone. The inaccessible nature of the deep crust (typically >15 km) forces reliance on analog samples and modeling results to interpret its bulk composition, evolution, and physical properties. A common practice relates major oxide compositions of small‐ to medium‐scale samples (e.g., medium to high metamorphic grade terrains and xenoliths) to large scale measurements of seismic velocities (Vp, Vs, Vp/Vs) to determine the composition of the deep crust. We provide a framework for building crustal models with multidisciplinary constraints on composition. We present a global deep crustal model that documents compositional changes with depth and accounts for uncertainties in Moho depth, temperature, and physical and chemical properties. Our 3D compositional model of the deep crust uses the USGS Global Seismic Structure Catalog (Mooney, 2015) and a compilation of geochemical analyses on amphibolite and granulite facies lithologies (Sammon & McDonough, 2021,
This content will become publicly available on May 13, 2024
The chemical composition of the deep continental crust is key to understanding the formation and evolution of the continental crust. Constraining the chemical composition of present‐day deep continental crust is, however, limited by indirect accessibility. This paper presents a modeling method for constraining deep crustal chemical structures from observed crustal seismic structures. We compiled a set of published composition models for the continental crust to construct functional relationships between seismic wave speed and major oxide content in the crust. Phase equilibria and compressional wave speeds (
- Award ID(s):
- 1952642
- NSF-PAR ID:
- 10416340
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Solid Earth
- Volume:
- 128
- Issue:
- 6
- ISSN:
- 2169-9313
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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