[On the] geochemistry and mineral chemistry of the Gabbroic rocks at Wadi Um Khors area, central eastern desert, Egypt

The studied metagabbro-diorite complex comprises hornblende metagabbro, quartz-metagabbro, appinitic-metagabbro, and quartz diorite beside the fresh gabbro relics. They are calc-alkaline and were emplaced at subduction zones related to island arc magma. They were subjected to metamorphism but still carry minor relics of fresh gabbro. Mineralogically, the metagabbroic rocks are composed of plagioclase [An 30-45], Ca-rich clinopyroxenes [diopside and augite] and hornblende of green and olive brown colour]. The obtained crystallization temperature for the coexisting plagioclase- olive brown hornblende mineral pair was 600 - 700 °C and for the coexisting plagioclase- green hornblende mineral pair was 800 - 900 °C. The Ca-rich clinopyroxenes are low in alumina content suggesting crystallization between 500 and 1100 °C at shallow depth. Also, the analyzed clinopyroxenes pertain to those found in sub- alkaline rocks. The studied metagabbroic rocks show relative enrichments in LILE [Sr, Rb, Ba] over the HFSE [Nb, Zr, Y], a feature characteristic of subduction- related magmas

Petrology, geochemistry and tectonic setting of Dyke swarms of Abu Dob area, central eastern desert, Egypt

Abu Dob granitic pluton is traversed by a large number of dyke swarms. The examined dykes are classified into acidic, intermediate, basic and alkaline. Most dyke swarms trend N-s to NNE-SW; some dykes trend NW-SE. The dykes are very steeply inclined at 75-85°. They generally possess a uniform thickness usually ranging from 0.5 to 40 m. The dykes sequence in Abu Dob area starts with the acidic, followed by the intermediate and then the Tertiary basalts and ends by the alkaline dykes. The intermediate and basic dykes are enriched in normative nepheline indicating their alkaline affinity, normative hypersthene is also present in trachydacite, trachyte, trachyandesite and in the alkaline basalt, Normative acmite appears in considerable amounts in the trachyte, phonolite and phonotephrite dykes pointing to a possible alumina deficiency. The mafic and intermediate dykes were possibly derived from alkaline magmas in a within plate environment, while the acidic dykes were derived from the late or orogenic calc-alkaline granitic magma and basalt sample has a tholeiitic nature. The dykes are enriched in HFS elements and depleted in LIL elements

Petrology, geochemistry and tectonic setting of some younger alkaline volcanic rocks, central eastern desert, Egypt

The present paper deals with some alkaline volcanic rocks occurring as small masses and plugs widespread in the Central Eastern Desert of Egypt. They occur in the form of plugs, sheet and dykes at Gebel El-Degheimi, Um Hombos, Um Khors plugs and Wadi El Miyah. The alkaline volcanic rocks are composed essentially of trachyte grading into trachyte, Qz-trachyte or phonolite. The studied volcanics contain acmite, aegirine and aegirine-augite. The alkaline volcanic rocks are enriched in alkalies and characterized by high contents in Nb, Y, Zr, Rb and Zn. Furthermore, the tectonic setting of these late volcanic alkaline rocks suggest that the trachyte masses erupted in a within plate tectonic environment. They were possibly derived from magmatic differentiation of an alkaline basaltic magma that suffered contamination with crustal material

On chromite mineralization and hosting serpentinites at Gebel Um Khasila area, eastern desert, Egypt

The present work deals with serpentinites and the associated chromite mineralization at Gebel Um Khasila area in the Central Eastern Desert, Egypt. Chromite occurs as lenses localized along thrust faults in serpentinites. The serpentinites were formed principally after peridotite to dunite constituting the base of ultramafic rocks of a dismembered ophiolite sequence. The serpentinites are similar to Alpine - type ultramafic rocks. The predominant occurrence of antigorite is almost identical to the regionally metamorphosed antigorite serpentinites.The chromite mineralization occurs as massive, nodular and disseminated crystals and may exhibit a pull-part texture. Alteration of chromite was initiated simulteaneously with the serpentinization and probably accelerated with the intrusion of the metagabbro-diorite, masses. Reaction rims of chromite with host rock was possibly initiated by ascending Fe-rich solution and altering the chromite composition

Intrapulmonary route for drug administration: effects on plasma concentrations and blood gases

This work aimed to compare four different methods of endotracheal and bronchial lidocaine administration with respect to the site of administration. Forty-eight patients undergoing elective operations with an anesthetic risk ASA I and II were included in this study. In this study, all other patients received lidocaine under bronchoscopic control through the side channel of bronchoscope either deep endotracheal, into the right main bronchus and into the right lower lobe bronchus. At 10 points of time after drug administration, blood samples were taken for measurements of lidocaine plasma concentration [using high pressure liquid chromatography] and blood gas analysis. Therapeutic blood concentrations [>/ 1.4 mug/ml] could be achieved and toxic blood concentrations [>/ 6 mug/ml] could be avoided with all methods of administration. No significant difference was found between the different methods with regard to peak concentration, time to peak, onset and duration of therapeutic levels or relative bioavailability. A significant decrease in PaO2 to 75% of the baseline was seen with all methods used