Geology: Ogun State has two main rock types. These are the basement complex rocks of the pre Cambrian age which are
Gateway International Hotel, Ijebu- Ode
made up of the older and younger granites in the northern parts of the state, and the younger and older sedimentary rocks of both the tertiary and secondary ages in the south ern parts (lloeje, 1983).
Relief and Drainage: Ogun State has a wide area of undulating lowlands belonging to the coastal sedimentary rocks of western Nigeria. There are scattered hills that are interfluves between the different river valleys.Some remnants of a large planation in the state include the out crop inselbergs found at Abeokuta the Olumo Rockat the southern edge of the Western uplands.
One implication of this location of the state is seen in all the rivers that traverse the state which flow southward either as tributaries or main rivers into the coastal lagoons and the Atlantic Ocean. These include Ogun, Osun, Yewa, Yemoji, Ona, Sasa, Oni, Ohu, Ohia, Abafon, Oyan, lju and others. Most of the state is welldrained by these streams and rivers, much of which dry up during the dry season.
Climate: Ogun State is located in the moderately hot, humid tropical climatic zone of southwest ern Nigeria. There are two
Obanta's Statue, Ijebu Ode
distinct seasons in the state, namely, the rainy season which lasts from March/April to 0ctober/ November and the dry season which lasts for the rest of the year, October/November till March/April.
The temperature is relatively high during the dry season with thi mean around 30°C. The harmattan, brought in the northeasterly winds from December February, has ameliorating effects on the dry sea son high temperatures. Low temperatures an experienced during the rains, especially between July and August when the temperatures could be a low as 24°C. The distribution of rainfall varies from about 1000 mm in the western part to about 2000 mm the eastern part, especially ljebu and Ogui Waterside LGAs.
Soils: Soils in Ogun State are varied accordini to the geological history and soil formation processes in the different localities. Soils in the northeri part of the state are derived from the basemer complex rocks and they belong to the red soils eastern part of the state, most especially ljebu East LGA support tree crops such as cocoa and coffee.
Ogun State University, Ago Iwoye
Soils derived from sedimentary rocks in the southern part of the state are also varied in the components and texture. Soils in the southwestern part of the state and most of the western part an sandy and could only support savannah vegetatior lfo LGA is noted for its limestone that was the base of Ewekoro cement factory that was located there The river valleys have alluvial soils.
Vegetation: Ogun State has two main types vegetation, namely, tropical rain forest and guine savanna. The tropical rain forest is found in the coastal areas in Ogun Waterside and the southern part of EgbadoSouth LGAs. Rain forests are found in some parts of the eastern LGA it such as ljebulgbo, Odogbolu, Sagamu and ljebu Ode. Guinea and derived savanna are found most of the western and northern LGAs includiniEgbado North and South, lfo, Ewekoro, Abeokuta, Owode and AdoOdo/Ota.
Ecological Problems: The intensive interactions of man with his environment in the state have created some ecological
Babcock University, llishan Remo ( A private University)
problems. These include the destruction of the rain forests through lumbering and the annual bush burning, both of which are responsible for the growth of deciduous forests and derived savanna which have replaced the original virgin vegetation.
Quarrying, with the blasting of the rocks in Abeokuta and environs and the quest for limestone and other minerals for the cement factories at Ewekoro and Sagamu, have left huge excavations and spoliation of the land. Water hyacinth(sea weeds) encroachment on the water ways on the major rivers, especially in Ogun Waterside LGA, is a pressing problem.