History of the Gambia The Courlanders remained dominant until 1659 when their possessions were handed over to the Dutch West India Company. In 1660, the Courlanders resumed possession, but the next year were expelled by the newly formed Royal Adventurers in Africa Company. In 1667, the rights of the Royal Adventurers to the Gambia were sublet to the Gambia Adventurers but later reverted to the new Royal African Company. 1677 saw the beginning of a century-and-a-half-long struggle between the English and French for supremacy over the Gambia and Senegal. The English possessions were captured several times by the French, but in the Treaty of
Geology of Gambia Geology of Gambia The geology of Gambia is defined by thick and comparatively recent sequences of sediments and sedimentary rocks, deposited in the last 66 million years. The country is underlain almost entirely by geologically recent Cenozoic sedimentary rocks. Much deeper basement rocks are likely present, although they are not well understood. Most research has focused on oil and groundwater exploration. The oldest rock units recognized in the west of the country, along the Gambia River are sandstones and kaolinitic claystones from the Oligocene, Miocene or Pliocene. Ironstone, including iron oxides, gravel, clay and sand dating to the Pleistocene are