Geochemistry and Petrogenesis of Basaltic Rocks and Enclosed Xenoliths from the Ghab Pliocene Volcanic Field in Northwestern Syria  

作　　者：Ali T. Al-Mishwat Safwan S. Dawod Ali T. Al-Mishwat;Safwan S. Dawod(Department of Earth and Environmental Sciences, Kuwait University, Kuwait City, Kuwait;Department of Geology, Damascus University, Latakia, Syria)

机构地区：[1]Department of Earth and Environmental Sciences, Kuwait University, Kuwait City, Kuwait [2]Department of Geology, Damascus University, Latakia, Syria

出　　处：《International Journal of Geosciences》2021年第8期667-688,共22页地球科学国际期刊（英文）

摘　　要：Basaltic rocks and their content of ultramaf</span><span style="font-family:Verdana;">i</span><span style="font-family:Verdana;">c xenoliths are common in the Ghab Pliocene Volcanic Field in northwestern Syria in the form of lava flows, cinder cones and pyroclastic deposits. The rocks occur within the Ghab pull-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">apart graben that formed by sinister strike slip faults within the zone that defines the boundary between the African and the Arabian plates. Three petrographic types occur: basanite, olivine basalt and more commonly alkali olivine basalt. The peridotite xenoliths are spinel lherzolite and harzburgit</span><span style="font-family:Verdana;">e.</span><span style="font-family:Verdana;"> Geochemical analysis indicates that the basalts are mostly alkaline to subalkaline. </span><span style="font-family:Verdana;">A distinctive feature of these rocks is the narrow compositional var</span><span style="font-family:Verdana;">iations in the content of most major oxides and minor elements, SiO</span>_{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;"> (44.33 - 46.43 wt%) and MgO (4.01 - 8.28 wt%). Some of the refractory and high field strength elements and incompatible minor elements in the basalts are relatively high (Cr average = 303 ppm and Ni average = 185 ppm) compared with </span><span style="font-family:Verdana;">their content in average basalts. These geochemical characteristics reflect cr</span><span style="font-family:Verdana;">ystallization of the Ghab basalts from pristine and primary magmas that have experienced minimal fractional crystallization and crustal contamination. Similarly, chemical compositions of the ultramafic xenoliths vary within a restricted geochemical range. They are compatible with the generation of these rocks from partial melting of a primitive mantle pyrolite to yield the xeno</span><span style="font-family:Verdana;">liths</span><span style="font-family:VerdBasaltic rocks and their content of ultramaf</span><span style="font-family:Verdana;">i</span><span style="font-family:Verdana;">c xenoliths are common in the Ghab Pliocene Volcanic Field in northwestern Syria in the form of lava flows, cinder cones and pyroclastic deposits. The rocks occur within the Ghab pull-</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">apart graben that formed by sinister strike slip faults within the zone that defines the boundary between the African and the Arabian plates. Three petrographic types occur: basanite, olivine basalt and more commonly alkali olivine basalt. The peridotite xenoliths are spinel lherzolite and harzburgit</span><span style="font-family:Verdana;">e.</span><span style="font-family:Verdana;"> Geochemical analysis indicates that the basalts are mostly alkaline to subalkaline. </span><span style="font-family:Verdana;">A distinctive feature of these rocks is the narrow compositional var</span><span style="font-family:Verdana;">iations in the content of most major oxides and minor elements, SiO</span>_{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;"> (44.33 - 46.43 wt%) and MgO (4.01 - 8.28 wt%). Some of the refractory and high field strength elements and incompatible minor elements in the basalts are relatively high (Cr average = 303 ppm and Ni average = 185 ppm) compared with </span><span style="font-family:Verdana;">their content in average basalts. These geochemical characteristics reflect cr</span><span style="font-family:Verdana;">ystallization of the Ghab basalts from pristine and primary magmas that have experienced minimal fractional crystallization and crustal contamination. Similarly, chemical compositions of the ultramafic xenoliths vary within a restricted geochemical range. They are compatible with the generation of these rocks from partial melting of a primitive mantle pyrolite to yield the xeno</span><span style="font-family:Verdana;">liths</span><span style="font-family:Verd

关 键 词：BASALT XENOLITH Ghab SYRIA PLIOCENE 

分 类 号：P58[天文地球—岩石学]