The Kilkile Emerald; Genesis, Mineralogy, Chemistry and Mining; Kilkile, Shakiso- Southern Ethiopia
| dc.contributor.advisor | Desta, Zerihun (PhD) | |
| dc.contributor.advisor | Getaneh, Worash (PhD) | |
| dc.contributor.author | Abera, Girma | |
| dc.date.accessioned | 2021-02-03T12:42:03Z | |
| dc.date.accessioned | 2023-11-09T14:11:08Z | |
| dc.date.available | 2021-02-03T12:42:03Z | |
| dc.date.available | 2023-11-09T14:11:08Z | |
| dc.date.issued | 2019-09-04 | |
| dc.description.abstract | This study provides quantitative geochemical, petrological, and mineralogical data on major rock types and emeralds of the kilkile area. The meta-basic rocks containing 740ppm Cr provided the amount necessary for emerald mineralization. Emeraldhosting biotite schist is confined to the contacts of quartz- feldspar- muscovite pegmatite dykes/veins with meta-basics. The pegmatite dykes are genetically related to a fertile granite pluton within the Adola district. The formation of biotite schist from meta-basic rocks is associated with the introduction of pegmatitic components in to the meta-basics, causing enrichment with the pegmatitic composition. Quartz-feldsparmuscovite pegmatites of the kilkile area belongs to the rare-element pegmatites of the LCT family with common beryllium enrichment (12ppm). These pegmatite dykes/veins intruded the N-S orienting regional structures. The emeralds have higher MgO (0.26-4.08 wt. %), Fe2O3 (1.39-2.18 wt. %), Al2O3 (17.7- 20.1 wt. %), CaO (1.25- 3.85 wt. %), K2O (0.07-1.7 wt. %), P2O5 (0.02-1.88) and Be (527-1000 ppm) and lower Cr2O3 (0.01-0.09 wt. %) and SiO2 (59.13-61.79 wt. %) contents. The relatively higher value of iron and magnesium in the kilkile emerald might attribute for the ferromagnesian nature of the meta-basic rocks or aggressiveness of the brine solution in liberating Mg and Fe from meta-basic rocks. The low chromium content in the metabasic rocks contribute for chromium deficiency in the emerald. The high value of Fe2O3 depresses the green colour in addition to low Cr2O3. Compared to the Zambian, the meta-basic rocks in the case of Ethiopia have low magnesium and iron content. However, the relatively higher value of iron and magnesium in Ethiopian emerald might contribute for relative competency of magnesium and iron in occupying the aluminium site in the crystal structure of beryl. The higher value of K2O in the Ethiopian emeralds than in Zambian might suggest the role of potassium metasomatism at the pegmatite and meta-basic contact. The genesis of Ethiopian emerald holds the classical model for emerald mineralization, the condition in which pegmatites interact with the surrounding meta-basic rocks. The current mining activity at kilkile area requires vertical to horizontal ratio chances due to the overlapping of mining progress with direction with the dipping of the host rock units. Therefore, low vertical to horizontal ratio is recommended for the western berms of the mining pits. | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/24958 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Kilkile Emerald | en_US |
| dc.subject | Genesis | en_US |
| dc.subject | Mineralogy | en_US |
| dc.subject | Chemistry and Mining | en_US |
| dc.subject | Kilkile | en_US |
| dc.subject | Shakiso- Southern Ethiopia | en_US |
| dc.title | The Kilkile Emerald; Genesis, Mineralogy, Chemistry and Mining; Kilkile, Shakiso- Southern Ethiopia | en_US |
| dc.type | Thesis | en_US |