Tanzania

Introduction

The coastline of Tanzania extends from about 4°30' S–10°30' S, a distance of just over 725 km (Alexander 1985). This general outline of the coast appears to have been established by faulting during the Palaeozoic, but local movements may have continued into the late Pleistocene and Holocene. This faulting has occurred within a narrow belt of Neogene sedimentary rock extending along the entire coast of Tanzania (Figs. 15.2.1 and 15.2.2 ). The sedimentary rock basin is generally separated from the crystalline basement rock of the interior by faulting, and lie in the down-faulted basin. Evidence from deep borings at a number of places indicates that there has been considerable subsidence of the coast during the Tertiary. Although faulting has blocked out the basic pattern of the Tanzanian coast, the geomorphological details have been determined by fluvial sediment supply, longshore currents generated by waves and tides, and the growth of mangroves and coral reefs.

Fig. 15.2.1