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Depth to Basement and Crustal Structure of the Northern Harrat Rahat Volcanic Field, Kingdom of Saudi Arabia, from Gravity and Aeromagnetic Data

Professional Paper 1862-K
Jointly published with the Saudi Geological Survey [as Saudi Geological Survey Special Report SGS–SP–2021–1]
By: , , , , and 
https://doi.org/10.3133/pp1862K

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Abstract

New gravity data reveal a prominent negative anomaly along the main vent axis of the northern Harrat Rahat volcanic field in the Kingdom of Saudi Arabia. The gravity low continues north of the volcanic field onto exposures of Proterozoic rocks, indicating that the low is caused not only by the volcanic field (and possibly underlying Cenozoic sediments), but also the underlying Proterozoic basement. An inversion of the gravity field guided by analysis of aeromagnetic data indicates (1) a broad depression of the basement surface that is deeper along the main vent axis in the eastern part and in the southwest part of the volcanic field and (2) less dense basement beneath the vent axis. Low densities within the basement most likely arise from lithologic variations in the basement, predating Cenozoic volcanism, although our analysis does not rule out small volumes of partial melt and higher temperatures or extensive fracturing at depth.

Suggested Citation

Langenheim, V.E., Ritzinger, B.T., Zahran, H.M., Shareef, A., and Al-Dhahry, M.K., 2023, Depth to basement and crustal structure of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia, from gravity and aeromagnetic data, chap. K of Sisson, T.W., Calvert, A.T., and Mooney, W.D., eds., Active volcanism on the Arabian Shield—Geology, volcanology, and geophysics of northern Harrat Rahat and vicinity, Kingdom of Saudi Arabia: U.S. Geological Survey Professional Paper 1862 [also released as Saudi Geological Survey Special Report SGS–SP–2021–1], 18 p., https://doi.org/10.3133/pp1862K.

ISSN: 2330-7102 (online)

ISSN: 1044-9612 (print)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Geology
  • Geophysical Data
  • Geophysical Anomalies
  • Modeling of Data
  • Discussion
  • Conclusions
  • Acknowledgments
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Depth to basement and crustal structure of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia, from gravity and aeromagnetic data
Series title Professional Paper
Series number 1862
Chapter K
DOI 10.3133/pp1862K
Year Published 2023
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description Report: v, 18 p.; Data Release
Country Kingdom of Saudi Arabia
Other Geospatial northern Harrat Rahat
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details