Mostly West German women peace activists and male supporters from the United States and several European countries descended today on Geneva, site of stalled talks on nuclear weapons, and formed a human chain between the U.S. and Soviet diplomatic missions.

Organizers described the symbolic linking of the two missions, located about 500 yards apart on the Avenue de la Paix (Street of Peace), as the launching of a week of protest activities here intended to express women's "deep concern about the arms race and to pressure the superpowers to hold serious and effective negotiations on arms control."

Many of the women among the estimated 2,000 demonstrators said they had walked about 800 miles, most of the way from West Berlin. The Women's March for Peace, which began Aug. 6, was halted at West Berlin's border with East Germany by East German authorities. The marchers were forced to continue the 110 miles to West Germany by bus, organizers said.

Over the coming week, the women are to demonstrate outside the U.S.-Soviet negotiating sessions on limiting European-based intermediate-range missiles and will try to press a list of demands on negotiators Paul Nitze of the United States and Yuli Kvitsinsky of the U.S.S.R.

A spokeswoman for the activists, Eva Quistorp of a West Berlin Women for Peace group, said the women's demands include a freeze on nuclear weapons production and testing, cancellation of U.S. cruise and Pershing II missile deployment, dismantling of Soviet SS20 missiles, inclusion of British and French missiles in the scope of the talks, and representation of the women's peace movement in the talks.