The Mineralogy of Clay Fractions in the Soils of the Southern Region of Jazan, Saudi Arabia

Journal Article

Al-Farraj, ِAbdullah S. . 2008

• نوع عمل المنشور: بحث
• رابط المنشور على الويب: http://scialert.net/fulltext/?doi=ja.2008.115.126
• الوسوم: Clay minerals, Jazan, Saudi Arabia, XRD, DTA, TGA, kaolinite, smectite, illite
• المجلة \ الصحيفة: Jownal of Agronomy
• رقم العدد: 2
• رقم الإصدار السنوي: 7
• الصفحات: 115-126

مستخلص المنشور

Because of very limited information of the clay minerals of Southern Jazan region (Saudi Arabia),  the mineralogy of the clay fraction  has been studied.  A total of nineteen soil samples  from five sites representing the main  landforms in the region  were studied.  X-ray  diffraction, differential thermal  and thermo gravimetric analyses  were carried  out on the samples.  Smectite,  kaolinite and illite were fmmd to be the predominant soil minerals. Other minerals present in small quantities included: Chlorite, quartz, feldspars. DTA confinned the low hydroxylation temperatures of kaolinite  (513-540°C), which  indicates  disordered crystallization of kaolinite. Moreover, TGA illustrated 4-6.6% (average 5.4%) weight loss related to dehydroxylation of kaolinite.  Therefore, the  ammmt  of kaolinite  minerals  was  calculated to be 29-47%  with  average  39%.  The clay  minerals  in the samples were similarity among  all the sites and this could  be explained by the fact that arid conditions  fmmd in the area does not support intense pedogenic processes.