asymmetry of the oscillation causes the bed forms to shift laterally at non-negligible rates. I will unofficially term cross stratification of this kind climbing-bed-forms cross stratification. Bed forms are said to climb when there is overall aggradation of the sediment bed while the bed forms are moving; see a later section for details.) 502
Swahili is the most spoken language in Africa, with over 100 million speakers. It is a Bantu language believed to have originated from other languages, mainly Arabic, due to historical interactions between Arabs from the Middle East and East Africans.
Nyanja (chinyanja), also known as Chewa (chicheÅµa) after the largest tribe speaking it, is a Bantu language spoken by over 15 million people in southern Africa. Chewa/Nyanja is an official language and common lingua franca in Malawi and Zambia, and is spoken by some in Mozambique, Zimbabwe and South Africa as well.