A three-dimensional gravity model of the geologic structure of Long Valley caldera
Several attempts to define and interpret this anomaly have been made in the past using 2-D and 3-D models. None of the previous interpretations have yielded definitive results, but in fairness, the interpretation here has benefited from a larger gravity data base and more subsurface control than available to previous workers. All published 3-D models simplistically assumed constant density of fill. All 2-D models suffered from the inherent three-dimensionality of the complicated density structure of Long Valley caldera. In addition, previous interpreters have lacked access to geological data, such as well lithologies and density logs, seismic refraction interpretations, suface geology, and structural geology interpretations. The purpose of this study is to use all available gravity data and geological information to constrain a multi-unit, 3-D density model based on the geology of Long Valley caldera and its vicinity. Insights on the geologic structure of the caldera fill can help other geophysical interpretations in determining near-surface effects so that deeper structure may be resolved. With adequate control on the structure of the caldera fill, we are able to examine the gravity data for the presence of deeper density anomalies in the crust. 20 refs., 7 figs.
- Research Organization:
- Lawrence Berkeley Lab., CA (USA)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 5390756
- Report Number(s):
- LBL-24572; CONF-8703199-2; ON: DE88006331
- Resource Relation:
- Conference: Symposium on the Long Valley caldera: pre-drilling data review, Berkeley, CA, USA, 17 Mar 1987; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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