The Tanzania Geological Society (TGS) Students’ Chapter recently conducted a geological excursion that saw members visiting important geological sites and mineral deposits in the country.
The tour was aimed at enhancing practical knowledge on geological processes responsible for the formation of various geological features and mineral deposits in the central and northern regions.
Speaking to the Daily News, the President of the TSG Students’ Chapter, Lutangilo Sakaf, revealed that the geological excursion, which enhanced practical understanding of various geological features and mineral deposits found in Tanzania, was an eye opener.
According to him, the objectives of the trip were to observe and identify geomorphic features throughout the route and understand the geology behind their existence.
“We also learnt and understood the geological processes behind the formation of various mineral deposits, their styles of mineralization, associated alteration patterns and depositional history,” he said, adding that the geological excursion trip also focused on identifying various problems or challenges in different geological sites that could be solved by the Students’ Chapter under research opportunities.
He went on to say that the field trip helped students to observe, identify and analyze geological structures such as veins and shear zones on drill cores, open pits and underground mine workings and to observe and identify various rock types present in various geological sites and also to understand the host rocks for different mineral deposits.
The TGS Students’ Chapter was established in 2019 with the aim of seeking and collecting self-driven, ambitious and motivated geology students from all the universities and institutions within the country and linking them to the industry by providing knowledge through field excursions, short courses, seminars and conferences.
“We would like to express our deep and sincere gratitude to our sponsors, Pan-African Energy and the Tanzania Geological Society (TGS) who made it possible for us to conduct our geological excursion smoothly,” he said.
Other stakeholders such as TANAPA, TAWA, the University of Dar es Salaam (UDSM) and The Ngorongoro Conservation Authority, Williamson Diamond Mine, Bulyanhulu Gold Mine, Geita Gold Mine and North Mara Gold Mine also supported the trip.
During the field excursion trip, according to him, students were able to learn and understand the geological processes behind the formation of various geological features and mineral deposits in Tanzania. He added that they also developed the ability to link the geology of all the visited sites and come up with a regional understanding of geology in Tanzania.
The nine-day field tour involved 30 members, two of them being instructors and the rest students from Dar es Salaam and Dodoma universities, participating.
The excursion trip saw the group visiting various areas such as the Uluguru Mountains in Morogoro, the Geological Survey of Tanzania (GST) in Dodoma, Senkenke artisanal mines in Singida, Shinyanga-Mwadui Williamson Diamond mine in Shinyanga, Bulyanhulu Gold mine in Kahama and Geita Gold mine in Geita Region.
Other areas are North Mara Gold mine in Mara region and Ngorongoro Crater via Serengeti National Park in Arusha Region. The journey started in Dar es Salaam saw Mountain Uluguru in Morogoro region being their first site to visit.
The students had an opportunity to learn and appreciate the Mozambique belt geology by looking at the Uluguru Mountains. And, during the same day, the students visited the Geological Survey of Tanzania in Dodoma region where they learnt on the history of GST, what GST is and its main activities and after that they visited the GST Museum.
Furthermore, on the second day of their trip, students visited Senkenke Mine in Singida region, first the students visited Nabii Eliya gold processing site. At the site they were able to learn on how gold processing is done using the VAT leaching process and cyanide chemicals to process it.
Sakaf noted that on the third day of the trip, they visited the Williamson Diamond mine in Shinyanga region where amongst many others, they learnt of the history of the mine and the interesting geology of the Mwadui Kimberlite.
The Mwadui pipe represents one of the largest diamondiferous kimberlites mined and a well-preserved example of a kimberlite crater in-fill or an albite without the tuff ring.
“On the next day we visited the Bulyanhulu Gold mine in Geita region. We were able to visit the underground mine site at reef 1. We descended two kilometers deep with the help of cars. Down there we were able to appreciate the shear zone hosted gold mineralization. We also had a chance to visit the core shed where we were able to appreciate drillholes’ cores cutting through the footwall, the sheared zone and the hanging wall,” he explained.
According to him, the journey continued to Geita Gold Mine where after the presentation they visited the Matandani open pit of the Kukuluma district. Here the students learnt about the main rock type which was intrusive rock (diorite) and granodiorite dykes.
The TGS Student’s Chapter Ms Sharon Athuman noted that students had the opportunity to visit North Mara gold.
She explained that at NMGM the students appreciated how geology occurs within a boundary zone between an older foliated volcano plutonic- sedimentary sequence to the south, and a northern sequence of largely sandstone, greywacke, and esitic volcanic, magnetic shales, and banded iron formation “On the next day we visited the Nyabirama open pit.
At the pit we saw that the majority of mineralization is hosted within altered granitoid rocks along a major structural (shear) zone, the Mara Shear. The deposit on the Mara Shear Zone is at a contact between granodiorite of which is the hanging wall and the Kewanja Tonalite in the north which is the footwall,” she said.
She narrated that the mineralized shear zone dips in the south direction and is associated with sericite and silica alteration. The barren footwall tonalite appeared to be relatively coarse grained, unfoliated and weakly plagioclase porphyritic while the barren hanging wall granodiorite was mostly blocky, massive and unfoliated.
Dolerite dykes cross cut across all units in several places. On the last day of the trip, the students visited Serengeti National Park where they passed through the Serengeti National park on the way to Ngorongoro and they were able to appreciate the Serengeti wildlife while learning the geology behind the Serengeti plains.
Through the help of tour guides, instructors and literature review and instructors we were able to learn that the Serengeti plains cover more than 5000 sq. km of the Serengeti and surrounding areas - almost a third of the park area and are probably what most people think of when you mention the Serengeti (it’s actually what the word means in Maasai - “endless plains”).
In addition, they visited Ngorongoro Conservation Area where they learnt that Ngorongoro Crater is an extinct volcanic caldera in the Eastern (Great) Rift Valley, saying Ngorongoro is thought to have formed about 2.5 million years ago from a large active volcano whose cone collapsed inward after a major eruption, leaving the present vast, unbroken caldera as its chief remnant.
The caldera’s floor is predominantly open grassland. It is home to a diverse array of animals including elephants, black rhinoceroses, leopards, buffalo, zebras, gazelles, and the densest population of lions in the world.
The students were unable to visit the Oldoinyo Lengai geological site due to the rough roads and therefore they started their journey back to Dar es Salaam appreciating the geology on the way.