Contribution to the petrography, geochemistry, and tectonic setting of the basalt flows of the Umm-Qais plateau, north Jordan

Öz

The Umm-Qais plateau is situated in north Jordan, south of the Yarmouk River. It consists of eleven basalt flows (about 190 m. thickness). The basalt flows belong to the Arabian Harrat volcanism. Petrographical, mineralogical and geochemical analysis of 11 rock samples indicated that the rocks are products of a continental intra-plate magmatism, mostly as coarse-grained silica-undersaturated olivine-rich alkali basalt (AOB). Nepheline and Fo-olivine are among the normative minerals. The age of the basalt flows can be correlated with the basalt of the northern extension of the Umm-Qais plateau north the Yarmouk River (Zamlat Bkhila plateau basalt) in the Golan Heights which was found to be 3.7±0.36-3.11±0.16 Ma. Flow eruptions are contemporaneous with the second spreading stage of the Red Sea during the Cainozoic over the past 5 Ma. Analysis of fractures showed mainly four dominant directions, namely ENE/WSW, NW/SE, NNE/SSW and NE/SW. They coincide with the trends of the Red Sea, Dead Sea transform fault, and some other distinct tectonic features.

Anahtar Kelimeler

• petrography
• geochemistry
• Yarmouk River

Contribution to the petrography, geochemistry, and tectonic setting of the basalt flows of the Umm-Qais plateau, north Jordan

Öz

The Umm-Qais plateau is situated in north Jordan, south of the Yarmouk River. It consists of eleven basalt flows (about 190 m. thickness). The basalt flows belong to the Arabian Harrat volcanism. Petrographical, mineralogical and geochemical analysis of 11 rock samples indicated that the rocks are products of a continental intra-plate magmatism, mostly as coarse-grained silica-undersaturated olivine-rich alkali basalt (AOB). Nepheline and Fo-olivine are among the normative minerals.

The age of the basalt flows can be correlated with the basalt of the northern extension of the Umm-Qais plateau north the Yarmouk River (Zamlat Bkhila plateau basalt) in the Golan Heights which was found to be 3.7±0.36-3.11±0.16 Ma. Flow eruptions are contemporaneous with the second spreading stage of the Red Sea during the Cainozoic over the past 5 Ma.

Analysis of fractures showed mainly four dominant directions, namely ENE/WSW, NW/SE, NNE/SSW and NE/SW. They coincide with the trends of the Red Sea, Dead Sea transform fault, and some other distinct tectonic features.

Anahtar Kelimeler

• North Jordan

Kaynakça

1. Barberi, F., Capaldi, G., Gasperini, P., Marinelli, G., Santacroce, R., Scandone, R., Treuil, M., and Varet, J., 1979. Recent basaltic volcanism of Jordan and its implications on the geodynamic evolution of the Afro-Arabian rift system. Atti Conv Lincei, 47. 667-83.
2. Blasband, B., White, S., Brooijmans, P., Dirks, P., de Boorder, and Visser, W., 2000. Late Proterozoic extensional collapse in the Arabian Nubian Shield. Journal of the Geological Society, 157, 615-628.
3. Brenner, I. B., 1979. The geochemical relations and evolution of the Tertiary-Quaternary volcanic rocks in northern Israel. Ph.D. thesis, Hebrew UniTv. Jerusalem, 202 pp.
4. Camp, V. E., 1984. Island arcs and their role in the evolution of the western Arabian Shield. Geological Society of America Bulletin, v. 95, p. 913-921.
5. Camp, V. E., 1986. Geologic map of the Umm Birak quadrangle, sheet 23D, Kingdom of Saudi Arabia (with text). Saudi Arabian Deputy Ministry for Mineral resources Geoscience Map GM 87, scale 1:250000, 40 p.
6. Camp, V. E., Roobol, M. J., 1989. The Arabian continental basalt province. Part I. Evolution of Harrat Rahat. Kingdom of Saudi Arabia. Geological Society of America Bulletin, v. 101, p. 71-95.
7. Colemann, R. G., Gregory, R. T., and Brown, G. R, 1983. Cainozoic volcanic rocks of Saudi Arabia. Saudi Arabian Deputy Ministry for Mineral Resources Open-File Report USGS-OF-03093, 82 p.
8. El-Akhal, H., Al-Tamimi, M., Greiling, 1999.Late Pan-African evolution and fracture pattern in the Sarmouj conglomerate, S W Jordan. Aspects of Pan African Tectonics. V. 32, p. 173-181. Forschungszentrum Jiilich, Germany.

9. Eyal, Y., Eyal, M., 1987. Mafic dyke swarms in the Arabian-Nubian Shield. Isr. J. Earth Sci. Vol. 36, 1987 pp. 195-211.
10. Floyd, P.A., Winchester, J.A., 1975. Magma type and tectonic setting discrimination using immobile elements. Earth planet Sci. Lett. 27. 211-218.
11. Garson, M. S., and Krs, M., 1976. Geophysical and geological evidence of the relationship of the transverse tectonics to ancient features. Geological Society of America Bulletin. V. 87. P. 169-181.
12. Ghent, E. D., Coleman, R. G., and Hadley, D. G., 1980. Ultramafic inclusion and host alkali olivine basalts of southern coastal plain of the Red Sea. Saudi Arabia. Amer. J. Sci, 280-284, 499-527.
13. Green, D. H., Ringwood, A.E., 1967. The genesis of basaltic magmas. Contrib. Mineral. Petrl. 90. 18-28.
14. Gregory, R. T., Coleman R.G., and Brown, G. F., 1982, Cenozoic volcanic rocks of Saudi Arabia. Evidence from continent for two stages of opening of the Red Sea. Geol. Sci. Am. Prog., 14 (7). 502 p.
15. Ibrahim, K. M., 1987. Geochemistry and petrology of some of the basaltic outcrops in central Jordan. MSc. Thesis , Univ. Jordan, Dep. Geol. Mineral. Amman, (Unpubl.). 164p.