The Carter administration, emphasizing its bolder support for black majority rule in Africa, is replacing the top offices at the State Departments Bureau of African Affairs.[WORD ILLEGIBLE] cludes the appointment yesterday of Richard M. Moose as assistant secretary of state for Africa, replacing William E. Schaufele Jr.

Moose, 45, now holds the department's sixth-ranking post, deputy under secretary for management. Although Moose's new rank is a level lower, he will join the activists directly shaping African policy: Vice President Mondale, U.N. Ambassador Andrew Young; David Aaron, deputy national security adviser to the President and former Mondale aide, and Anthony Lake, director of the State Department's Policy Planning Staff.

Two of the present three deputy assistant secretaries in the African Bureau also are scheduled for replacement, informed sources said, with a fourth deputy to be added, on economic policy. Official deny "any purge"; changes at deputy level are described as "normal rotation."

The leading choice to replace Moose in the managerial post, State Department sources said, is Frank C. Carlucci, ambassador to Portugal. Carlucci, although a career diplomat, ws known as a hard driving troubleshooter for President Nixon in various domestic agencies before his assignment to Portugal in 1974.

Aaron, Lake and Moose are leaders in the younger coterie of liberals inside the administration with close ties to liberals in Congress.

Schaufele is scheduled to become ambassador to Greece. He worked with former Secretary of State Henry A. Kissinger in beginning to turn U.S. policy from alignment with Africa's white minorities toward black nationalism, at the end of Kissinger's term. Carter administration policy, a leap beyond, now stands in frontal challenge to South Africa's apartheid, as well as to white minority rule in Rhodesia and Namibia (Southwest Africa).

Secretary of State Cyrus R. Vance asked Schaufele to continue until the Carter administration could decide on its own appointee. His successor, until last month, was intended to be J. Wayne Fredericks of the Ford Motor Co., who was a deputy assistant secretary for Africa in the Kennedy administration. A traffic accident in London, followed by a fall in his home, took Fredericks out of consideration.

Moose acknowledges he preferred to remain in the departmental manager's post, but is highly interested in Africa. His selection to succeed Schaufele follows a two-week trip to Africa last month, with Young part of the time, and a flight back from Europe with Mondale, returning from his separate, stern talks with South African Prime Minister John Vorster.

Vance afterward asked Moose to head the African bureau following Fredericks' accident.

Once factor in Moose's appointment in his access to liberals in Congress on Africa policy. Moose, who served in Africa as a young Foreign Service office, was twice assigned to the National Security Council staff, before joining the Senate Foreign Relations Committee staff in 1969. In 1975 he traveled in Africa with Sen Dick Clark (D-Iowa), chairman of the Africa subcommittee, and worked with Clark and others to block Kissinger's original policy in Angola, for Central Intelligence Agency support of Anti-Marxist factions in Angola's civil war.