13th - 14th May, 2023
ITINERARY
The Purpose of the field excursion will be to see the potential source and reservoir rocks within the Lamu basin. Delegates will be driven northwestwards from Mombasa along Mombasa Kilifi highway. Rock types to be encountered include the Mazeras Sandstone (potential reservoir), Maji ya Chumvi beds (potential source rocks) and the Taru Sandstones (potential reservoirs). The rock sequence will be from the youngest to the oldest. There will be several stops along Mombasa Road after which delegates will be driven through the Tsavo East National Park for a game drive.
Day 1
Stop 1: This will be at a road cut near Mazeras town to view an exposure of the Mazeras formation, one of the potential reservoirs in the Lamu Basin. The shale intercalation can act as a source and seal rock.
Stop 2: Delegates will be able to view the Maji ya Chumvi siltstones at one of the several small quarry sites near Maji ya Chumvi town.
Maji ya Chumvi beds contrast with the Taru grits by their dominance with the argillaceous components. They overlie the Taru grits with a slight disconformity. They are characterized by thinly bedded shales in silty sandstones or fine sandstones so that they easily split into slates or slabs along the shale partings.
Maji ya Chumvi beds can be divided into two series: the lower beds and the upper beds. The Lower beds consist of shales with variable colours that range from bluish, black, red brownish, and are comparatively easily eroded than sandstones. They form broad valleys along their strike with drainage pattern clearly illustrating variations in their lithological successions. The Upper series of the Maji ya Chumvi rocks start with the first appearance of siliceous sandstone beds as we pass upward from shales to silty shales. In the south around Samburu town, soft yellow-coloured sandstones and hard yellow and white quartzitic layers are found interbedded with the soft blue micaceous shales.
Stop 3: At Taru Quarry. The Taru Grits Formation comprise of the Lower Duruma sandstones and are largely composed of four units namely Basal unit, the Arkose unit, the sandstone group, and the Calcareous unit. It is essentially a fluviatile formation derived directly from the Basement system rocks further west.
Stop 4: Tsavo National Park was established on 1st April 1948 with an area of 21,812km. It is the largest Park in Kenya. In May 1948, Tsavo National Park was divided into East and West for administrative purposes. The two Parks are divided by Nairobi–Mombasa railway/ road. Tsavo East is a very popular park as is indicated by the high numbers of tourists visiting it per year. Some of the attractive scenic features includes large herds of game such as elephants, giraffes, zebras, antelopes, birds, reptiles, insects, and flora all worth watching. Delegates will spend the evening at Voi thereafter.
Day 2
Delegates will be driven from Voi towards Mombasa along Nairobi Mombasa highway for about 138km. There will be one stop along Mombasa Road after which delegates will be driven through Mazeras - Kaloleni - Kilifi Road.
Stop 1: Kaydee Quarry
A visit to the Kaydee Quarry where Mariakani sandstone rocks are mined to produce ballasts that is used for the roads and building construction industry.
Stop 2: At the Bridge between Mazeras and Kaloleni town to view an exposure of the Mariakani sandstone. Mariakani sandstone exposure is about 8km from the junction of Mombasa- Kaloleni tarmac road. It consists of massive, cross-bedded, quartzo-feldspathic sandstones and grits, with interbedded shales. At the bridge a good exposure of sandstone incorporated with large, rounded clasts of mudstone which appear to have been preferentially weathered and washed away leaving remnants of hollow spherical voids or casts will be observed. In other areas some of these voids appear to have concentrated minerals like silica or calcites making up some hard-rounded concretions. Mariakani sandstones have a characteristic mottled appearance and on the outcrop level, it very well consolidated and has poor porosity.
Stop 3: The Jurassic Kambe Limestone Exposure.
The exposure is 17km from Kilifi-Mombasa tarmac road. The outcrop shows a calcarenite member of the Kambe Limestone with well bedded calcarenite facies that displays well exposed vuggy and dissolution voids as well as fracture porosities. Kambe Limestone is one of the potential reservoir rocks in the Lamu Embayment. Other potential reservoir units include the Mazeras sandstone of the Permo-Triassic age (or Karroo), Frere town limestones (Cretaceous) and Tertiary rift carbonate buildups and fluvial/deltaic sandstones (of Tertiary age).
Stop 4: Haller Park (formerly Bamburi Nature Trail) is located south of the Bamburi cement plant along the Mombasa /Malindi highway. A product of the company’s efforts, since 1971, to convert barren landscape of disused limestone quarries into vibrant and diverse ecosystem of forest, grasslands, and ponds.
Currently, Haller Park plays host to a variety of wildlife including hippos, giraffes, buffalos, and antelopes as well as smaller mammals and birds.
The Park was the first recipient to be honoured with the United Nations Environmental Program Global 500 Roll of Honour award for the unique, ecologically sound, and successful rehabilitation undertaken.
Fees: US$900 per person
Cost- includes transport, accommodation, meals, and park fees. Delegates should also ensure that they have appropriate field gear e.g., field boots.
Contact:
Mr. Josky Kisali,
Senior Geologist
Ministry of Petroleum and Mining
Nyayo House, 22nd floor,
P. O. Box 51614 – 00100,
Nairobi, Kenya.
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Telephone: +254 20 310 112
Cell phone: +254720 116 524