The Salma Caldera complex, northeastern Arabian Shield, Kingdom of Saudi Arabia
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- Document: Report (pdf)
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Abstract
The upper Proterozoic Salma caldera is genetically part of an elongate alkali granitic massif, Jabal Salma. Comenditic ash-flow tuffs, the oldest recognized rocks of the caldera complex, were erupted during caldera collapse associated with the rapid evacuation of the upper, mildly peralkaline part of a zoned magma reservoir. Within the tuff sequence, a massive, lithic-rich intracaldera tuff containing megabreccia blocks is overlain by a layered ash-flow sequence. Later peralkaline granite intruded the caldera ring fracture zone. Metaluminous to peraluminous magma rose beneath the caldera approximately 580 Ma ago and solidified as biotite alkali-feldspar granite, syenogranite, and granophyre. No apparent structural doming of the exposed volcanic rocks along the east side of the caldera took place, and post- emplacement deformation and metamorphism of the caldera are minimal.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | The Salma Caldera complex, northeastern Arabian Shield, Kingdom of Saudi Arabia |
| Series title | Open-File Report |
| Series number | 85-370 |
| DOI | 10.3133/ofr85370 |
| Year Published | 1985 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Description | i, 23 p. :ill., maps ;28 cm. |
| Country | Saudi Arabia |
| Online Only (Y/N) | N |
| Additional Online Files (Y/N) | N |
| Google Analytic Metrics | Metrics page |