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

Basaltic rocks and their content of ultramafic 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- 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 harzburgite. Geochemical analysis indicates that the basalts are mostly alkaline to subalkaline. A distinctive feature of these rocks is the narrow compositional variations in the content of most major oxides and minor elements, SiO2 (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 their content in average basalts. These geochemical characteristics reflect crystallization 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 xenoliths. These magmatic processes operated during the Pliocene in a regional transtensional stress environment attending the development of the Dead Sea Rift.

Barrellite and Pillarrite: A Description and a Mode of Formation of a Novel Post-Sedimentary Twin Structures from As-Subbiyah, North of Kuwait Bay, Kuwait

I report on the occurrence of a pair of novel and related post-sedimentary structures that form in the Neogene cross-bedded red sandstones in the As-Subbiyah area, north of Kuwait Bay, Kuwait. I named them barrellite and pillarrite. Barrellite forms as vertical tubes of concentric sheaths of siltstone with partially hollow interior or intervening homogeneous and structure-less sandstone. It stands as barrels above the background sandstone. Pillarrite forms as discrete, vertical and solitary spines of homogeneous sandstone and siltstone, or inside barrellite masses from which successive siltstone sheaths were stripped. The structures range in diameter from one-centimeter poke marks to one-meter-wide barrels and hunks, and their vertical length exceeds two meters. Barrellite, pillarrite and their complex intergrowths develop near thin quartz veins and chaotic zones, and form with them complex geometrical relationships. The dual structures are genetically related and fall within the general class of tubular structures in sedimentary rocks. I consider them as a special type of sand injectites. The mode of formation of these structures is enigmatic. They develop in a geological setting that displays evidence of a widespread and vigorous oil field brine. I suggest a tentative scenario for their formation, involving flushing of the brine through hydraulic fracturing of the sedimentary succession above the Ebharah Oil Field reservoir in the As-Subbiyah area. The brine plucks mineral and rock fragments and mixes with them along its paths, producing a heterogeneous slurry. Ultimately, the slurry solidifies as barrellite and pillarrite, chaotic zones and quartz veins. The vertical nature of the structures, circular and internal concentric arrangements, as well as the homogenous lithology inside their masses mimic characteristics of flow and deposits in vertical and horizontal pipelines.

A FORTRAN Software Application to Decode Geographical, Lithological, Political, and Bibliographical Information from the IGBADAT International Database on Igneous Rocks

GEOLITH is a FORTRAN program designed primarily to extract and decode geographical, lithological, political, and bibliographical information from the international igneous rocks database IGBADAT. It fetches the following information: sample name, sample latitude and longitude locational coordinates, name of specimen contributor to the database, nominal field and proper rock names, name of geological unit, name and title of rock groups, name of country and province of sample, and sample cultural location. Rock group name and title and geological unit name are decoded directly by simple manipulation and translation of text strings, while other types of information utilize pneumonic representations for decoding. Users interrogate the IGBADAT (and similarly-structured databases) fully, producing a voluminous wealth of data. Output from the GEOLITH software tool is a flat ASCII text file containing the decoded information. A spreadsheet-compatible file containing the output results is also produced. The latter file is ready for inclusion into a spreadsheet like EXCEL. An error file also results from the application of the GEOLITH program.

OXDPPM: A Software to Convert Chemical Elements Between Oxides and Native Elements

OXDPPM is a simple, but powerful, FORTRAN software program designed for conversion of concentrations of chemical elements. Specifically, it converts the concentrations of elements in any material from oxide percentages to pure native elements, and vice versa. Each chemical element has a conversion factor associated with each of its oxides. The software invokes two modes of operation: data input by mainstream files (F Mode) and data input by interactive dialogue with the computer screen (I Mode). Each of the two modes permits two opposing conversion directions, either converting element content from oxide percentage to parts per million of native elements (0 Mode), or converting the data from native element parts per million to oxide percentage (1 Mode). The program differentiates between 2-and 1-letter element symbols and converts accordingly. A native element converts to the most common oxide in multi-oxide elements. In the F Mode, users need only to supply the program with the name of an input file. Three output files are generated internally: a flat text file containing the results of element conversions, a second file containing the same results in a space-delimited and spreadsheet-compatible file ready for export to a spreadsheet like EXCEL, and a third file containing the element conversion factors. The I Mode produces three similar files. The OXDPPM software is a stand-alone program. With a proper linking, it may be inserted as a module in existing programs or as a dll routine in dynamic libraries. The program launches from the system command prompt or from the program icon on PCs and laptops operating under the WINDOWS environment.