The Parana’- Etendeka flood basalt province is kown as one of the largest continetal igneous province with a volume of about 1 x 106 km (Jerram et al., 1999) The Etendeka Igneous Province located in Namibia forms in the Eastern parts of the Parana’-Etendeke flood basalt province and represnts less than 10% of the Parana’- Etendeka with approximatly 800 000 km2. (Ewart et al ,1998). Althouth, it only covers a very small proportion, it preseves excellent rock exposures in the Namib desert envirnment which makes it a significant area for both the studing of detailed stratigraphy and significant anylisis of emrical internal stratigraphy which has produced information of the palaeo-volcanic features such as the shield volaneos (Jerram et al,1999) Etendeka encompass, compositionally, bimodal extrusive and intrusive material with significant basalts and quartz latites. (Renne, 1996). This essay will examine two significant igneous well exposed out crops in the Etendeka, namely the Gobobseb sequence and the Messum igneous complex, with the purpose of exploring the possible igneous petrology, by using the minerology and infered stages
The Gobobseb sequence cover an enourmous area of apprixmtly 1,100 km2 . The dominant rocks found in these rather profound feature, are assigned to the Awahab formation and forms intebedded igneous basalt and quartz latites. The Goboboseb is known to have originated from the Awahab Formation magma system from which a total of ~ 8600 km3 of igneous material was erupted. (S.C. Milner,1995)
It is generally catageroused into the lower portion possesing Tafelkop Basalt member. This bottom base is known to be quite thick and consists of very well preserved amygdoloidal flows. Excatly after the thick base, there appears finley distinguishble three quartz latite lava flows form. I will denote the as I,II,III. They consist of quartz latite member and are about 100-150 m. Also they are basaltic and are about 130m (Ewart et al, 2002)
Scientific research depicts that the profound Goboboseb originated from the neigbouring Messum complex and that an occurrence of an eruptive large silica magma system,named the Awahab formation, produced it. (Ewart et al, 1998) The mountain, in addition to the various segments, consist of doletire dykes, sills as well as plugs.The occurrence of certain chemically unique dykes and lava within the Tafelkop member means that some of the basalts rock emanated from significant volcanic edifice related to the Messum. (Ewart et al, 1998)
The overall sequence consist entirely of mafic lavas which are futher sub-divided into different series which are low in Ti and Zr and also ones hing in both Ti and Zr. I will denote the low Ti and Zr as LTZ.L and the hing in Ti and Zr as LTZ.H. The LTZ.H consist of magnesum, alkaline to tholetiitic lavas, with a great amount of oliv + cpx phenecryst assembledge. They are a results of a possible occurrence of a mantle plum melts. (Ewart et al, 1998) The LTZ.H, on the other...