The miners, arrested after 44 people were killed at the platinum mine last week, have been held on public violence charges in Garankuwa Magistrate's Court, north of Pretoria, the South African Broadcasting Corp. reported.
Thirty-four of those who died were killed in a clash with police Thursday, while 10 others died in earlier violence at the mine, SABC said. AllAfrica.com reported 78 people were wounded.
A magistrate granted prosecutors' request for a one-week postponement for the defendants' next hearing to allow time to complete the investigation.
AllAfrica.com reported prosecutors said the investigation was made more difficult because some of the miners are immigrants who speak various languages. The news Web site said the court proceedings were interpreted in several languages.
During the morning, a group of women protested in the court building, demanding their relatives be freed. Police told them to leave the building and they moved their protest a nearby street, AllAfrica.com said.
Other workers at the mine defined the mine owners' Monday ultimatum that they return to work or be fired.
About three-quarters of the 3,000 miners did not show up, The Guardian reported.
One miner told the British newspaper: "We are going to continue fighting for what we believe is a legitimate fight for living wages. We would rather die like our comrades than back down."
The platinum mine in Marikana in North West province is owned by Lonmin, a firm based in London.
A week of mourning has been declared by President Jacob Zuma. He ordered flags to fly at half staff and has created a ministerial-level task force and set up a judicial commission of inquiry.
Zuma said in a statement: "The nation is in shock and in pain. We must this week reflect on the sanctity of human life and the right to life as enshrined in the constitution."
He has been criticized for his handling of the situation, including by expelled African National Congress Youth League President Julius Malema, who called for him to step down in the wake of the labor strife and violence at the mine near Rustenburg, about 60 miles northwest of Johannesburg.
Rustenburg was a host city of the 2010 FIFA World Cup men's soccer tournament.
Zuma "presided over a massacre," Malema told thousands of angry miners Saturday, and called on all South African miners to go on strike in solidarity with those gunned down by the police Thursday.
Malema is campaigning against a second term for Zuma ahead of the ANC's congress in December.
Zuma announced Sunday the appointment of an inter-ministerial committee to investigate Thursday's shooting, when police fired live ammunition on machete-wielding, striking mine workers.
Institute for Democracy in Africa Executive Director Paul Graham told the British newspaper The Daily Telegraph: "It is very disappointing that those appointed to the commission of inquiry include Cabinet ministers. They cannot be independent and will not be trusted."
Detectives from the Independent Police Investigative Directorate, whose purpose is "to ensure independent oversight over the South African Police Service," said they recovered 45 guns from the massacre site and said 300 bullets were fired in 60 seconds.
Investigators said they had 180 witnesses to the deadly episode.
Lonmin management defended the ultimatum, denying the company was being smug and callous.
"We have not been arrogant," acting Chief Executive Officer Simon Scott told the Telegraph. "We have to rebuild the Lonmin brand, rebuild the platinum brand and brand South Africa."
The company said it was monitoring the situation with police and would extend the ultimatum date on their advice.
"The safety and security of our employees is paramount and nobody will be asked to report for duty if the police consider them in danger of reprisals," Scott said.
About 3,000 rock drillers have been on a wildcat strike since Aug. 10, demanding their wages double as part of a battle between two unions seeking to represent them.