A. Al-Malabeh

Factors Determining the Choice of the Construction Techniques in Petra, Jordan

The purposes of this article are to study the types of construction techniques that the Nabataeans used to bring Petras architecture to its peak, and to identify the underlying factors behind their choice of these techniques. To achieve these purposes, the focus will be on the geological setting of the site. Also presented are consideration of the classification of the buildings and analysis of architectural techniques used in the city. The results of the study reveal that the Nabataeans were influenced in the choice of their capital by its site, their outside contacts, and building materials. Their technical knowledge was refined to suit the properties of the locally available materials, most notably sandstones. This article also includes background on the historical context of the buildings and their structural stability. This record of materials and techniques are essential as preparatory procedures for a successful repair and when providing guidance for architects, surveyors, and craftsmen involved in the conservation at Petra structures.

Mineralogy, geochemistry, and origin of felsic dike swarms in Aqaba complex (Wadi Al-Yutum), South Jordan

The present work deals with the geologic setting and mineralogical and geochemical study of Late Precambrian magmatic rocks especially the felsic dike swarms of northeast Aqaba complex in South Jordan. The northeast Aqaba complex represents one of the most significant regions in the South Jordan basement. The basement rocks in the studied region are composed of schists, gneisses, migmatites, met gabbros, diorite, and granite. It is invaded by post-orogenic dike swarms. The post-orogenic dike swarms have been recognized as felsic dikes of dacite, rhyodacite, and rhyolite composition. They are composed of plagioclase, K-feldspar, quartz, biotite, and hornblenble with a porphyritic texture. Chemically, they are enriched in compatible elements especially in the large ion lithophile elements such as K, Rb, and Ba. The values of A/NK are more than A/CNK, indicating that dacitic dike swarms have metaluminous nature. Meanwhile, the values of A/NK are less than A/CNK in rhyodacitic and rhyolitic dike swarms of prealuminous nature. This felsic dike can be related to an intercontinental setting that was accompanied by a chemical evolution of the extensional movements and is formed by partial melting of crustal rocks, which are already known from other areas in the northeast portion of the Arabian-Nubian Shield.