The complex entity people call “Onitsha” deserves respectful accounts — written, pictorial, aural, etc. — that illuminate its importance (ecological, demographic, historical, economic, political, aesthetic, religious, etc.) and that also record its stature as a long-suffering center of human as well as non-human existence. The website being constructed here contributes toward that aim, recognizing as the Nigerian writer Chinua Achebe (who grew up in its urban environs during the 1930s) memorably stated, that some of the remarkable cultural contributions appearing in Onitsha in recent times may need to be understood as emerging from within a “zone of occult instability”¹.

Achebe was talking about “the amazing pamphlet literature of the Onitsha market” which came to the world’s attention in the 1950s, and he says:

“One of the most intriguing questions concerning this literature — Why did it happen in Onitsha? — has however, not yet been answered fully and I suspect never will be…. It is this area which interests me — the esoteric region from which creativity sallies forth at will to manifest itself. All we can do is to speculate. Onitsha is such a phenomenon. Whenever I think of it, a phrase from Frantz Fanon comes immediately to my mind: a zone of occult instability.”

Actually, if you observe the location of Onitsha broadly enough over land and deeply in time, it reveals the presence of instabilities of a very different kind as well (though some surely fit the rubric of what is today “occult”).  Geographically, Onitsha’s position as a mere local flank of a very large river is almost unique: as you see from the image at left (roughly centered on Onitsha), where the city location is marked by a tiny red dot, it stands on the riverside edge of extensive uplands that spread out to the east, and also confronts an apex between two vast triangular floodplains, one spreading out northward (upstream) for 70 miles to its culmination near the contemporary city of Idah, the other (the immense Niger Delta, still subsiding under the weight of accumulating sediment) expanding southward for more than 100 miles where its numerous, spreading “distributaries” eventually reach the sea².   When the Niger River first did that, it happened at the site now called Onitsha.

The geological processes that explain this topographic peculiarity relate to the fact that (during what likely seem to today’s residents of the city to be unimaginably ancient times) the physical earth of the entire region tore (“rifted”) apart, creating what geologists now call the “Benue Trough”. Geologists tell us that a  rifting of the African continent partially spread open here, as shown on the map to the right, beginning in late Jurassic and early Cretaceous times, from some 150 to 130 million years ago (MYA) and continuing to 80 million MYA.³.

The rifting shown on this map was a minor part of the much larger rift-expansion that built the Atlantic Ocean beginning during these times, and in some phases of this process the emerging Atlantic surged into this part of the African Plate, with seas extending sometimes northward into what is now Sahara Desert. Subsequently, the entire trough was subjected to a complex series of compressions, foldings and “twistings” that eventually produced (after many millions of years of intervening geological work) the unusual uplands-and-floodplains combination that we see on the ground today.⁴.  The Benue Rift also produced extensive tin deposits, important for our later story.

We will pursue geological facts no further here (indeed, late 20th- and early 21st-century geology of this area seems  almost as dauntingly complex as quantum physics does to the layperson writing these words), but it seems worth noting that the Anambra Basin (part of the Anambra syncline, the Anambra Platform, eroding and then subsiding over a very long time) attains in some places sedimentary deposits many thousands of feet deep and contains substantial deposits of petroleum. The utterly flat alluvial floodplain that we see north of Onitsha today is merely part of the western edge of this much larger geostructural basin.

The dominant geomorphic feature of Onitsha’s prehistoric but human situation is the Niger-Benue watershed, the expanse of which is shown on the map below (the Benue  River runs from the east to meet the Niger at Lokoja):

The combined length of these two rivers far exceeds the distance across all 48 contiguous states of the United States of America.  And the headwaters of each one lie in tropical uplands that receive the annual monsoons generated by the seasonal movements of the Intertropical Front: Both the Fouta Djallon and Loma Mountains of Guinea (prime headwaters of the Niger) and the highlands of eastern Nigeria, Cameroon, and Chad (main sources of the Benue) receive heavy rainfall from June through September, and sustain a relatively dry season from November through March.

This dictates a a regime of seasonally rising and falling volumes in the waters that carve their way through these great basins.  Specialists in hydrology distinguish the floods that reach our Onitsha area according to their different sources, but the greatest annual flooding of the Lower Niger area comes in September and October of every year, and in the vicinity of Onitsha, the difference between high water and low water can reach as much as 35 feet.⁵  Despite the recent building of numerous dams along the Niger tributaries, flooding of the Lower Niger valley lowlands still occurs, as can be seen in this satellite image from October of 2012⁶:

Onitsha lies at the bottom of the map.  At the top, you can see that the Benue River is contributing the great mass of the flooding, which covers the entire Anambra Basin.  (Note too the heavy contribution of the Anambra River.  Local rains contribute significantly to this seasonal flooding.) The Anambra (in Igbo, omambala, “plain floods”) floodplain is some 60 miles in length, and “in most years provides a wetland of 165,000 hectares”⁷

This ancient geographical instability has been crucial to the livelihoods of the people who have become involved in this region, producing great imbalances in modes of residence, livelihood, politics, and other features of life.

Culled From AMightyTree.org