Geology And Mineral Potential Of Northwest Yemen

The Republic of Yemen (Yemen) occupies the southwestern corner of theArabian Peninsula, being confined by longitudes 42o- 53oE and latitudes 12o- 20oN. It extends along the southern part of the Arabian Peninsula on the Gulf of Adenand meets the Red Sea to the west and Saudi Arabia is to the north and Oman tothe east. The approximate surface area was estimated at 527,970 km2 (203,750square miles) including the Socotra archipelago (extending between 52o - 54oE,and 12o - 13o 45??. The history of Yemen stretches back over 3,000 years, was being one of theoldest centers of civilization in the Near East. The discovery of metal wastealongside melting furnaces, casting moulds and pieces of earthenware (porcelain)in many places in Yemen is the confirming evidence of the active mining andmetal works in ancient Yemeni. Unfortunately, except oil and salt Yemen's minerals industry is only of minorimportance. The commodities contributing to the Yemen economy at presentinclude salt, gypsum, and building stones. Though much geological andexploration works have been carried out exclusively recent 40 years in Yementhrough bilateral assistance programs or extended contracts, the metallic andprecious metals in Yemen are still out of the exploitation stage.190Ph.D Thesis, Al-Nagashi A. M.S As a developing country, Yemen needs its mine industry. So the mainobjective of this thesis is to increase the understanding of the geology of NWYemen and to outline the mineral potential of the northwestern parts of theRepublic of Yemen, which, the present author believe, and the Ministry of Oil andMineral of the Republic of Yemen agree upon, are more important for theminerals than other parts at present stage, after more than 40 years of fruitlessgeological research and exploration, than doing some research on a specificexploration target. The main methodology used is to collect all geological,geochemical, geophysical and remote sensing data to make comprehensivecomparison with some known deposits and geological settings worldwide and tocarry out a throughout analysis. However, this seemingly routine work proven tobe terrible trial, even just to get piece of information would take much effort andenergy. Fortunately, after harsh work of more than three years, some positive andencouraging results are gotten as the followings: (1) Based on previous data, and according to analysis on litholigicalassociation of exposed impacted marine sedimentary sheets, turbidite rockssuccession, well development of ophiolite succession and ultramafic rocks of themarine upper mantle, predominant parallel deep-seated faults, as well as theirspatial relationship to other terrane, a new Precambrian terrane, which issuggested to belong to an accretion wedge between the oceanic crustal terrane andmagmatic arc and are most potential terrane for hosting different types of mineraloccurrences, is proposed for the first time. The attributions and genesis of otherfour terranes are also clarified and outlined. (2) Based on data available, relatively comprehensive and completedescriptions of some 80 mineral occurrences at different tectonic settings are 191Summaryfinished with emphasis on their probable genetical implication and within theirtectonic frame and host rock environment. (3) Using the method developed by geologists of USGS, and referring to thesimilar deposits models by USGS and BC, four mineral deposit models have beenset up for 4 important mineral prospects, namely the Hariqah, Jabali, Suwar,Waraqah as a first try, corresponding to sedimentary-hosted Au,carbonated-hosted Pb-Zn, mafic-intrusion related Cu-Ni, and hot spring Au-Agrespectively. (4) According to metallogenic series conception proposed by Chinesegeologists, 6 mineralization series of different mineral occurrences and 15 deposittypes probably occur in NW Yemen...