* Rio announced reforms for heritage management processes

* Aboriginal group says it has no visibility into Rio's plans

* Rio has pledged better communication with Aboriginal groups

* Investors say they are closely monitoring industry

MELBOURNE, March 23 (Reuters) - An Australian Aboriginal group on whose lands Rio Tinto Ltd mines for iron ore said that heritage reforms Rio announced on Tuesday lacked detail and that it had yet to see an improved approach to cultural heritage management.

Rio Tinto outlined its plans earlier on Tuesday to improve its heritage management practices, 10 months after it destroyed 46,000-year-old rock shelters at Juukan Gorge in Western Australia against the wishes of traditional owners, causing public outcry.

Rio said it would form an Indigenous advisory group to help it better understand issues affecting Indigenous Australians, identify gaps in the company's current protocols and provide a clear pathway to best practice and re-establish trust over time.

Tony Bevan, a director at Wintawari Guruma Aboriginal Corporation (WGAC), one of nine Aboriginal Corporations that have agreements with Rio, said in a statement that the miner had not provided them any details on the plans, which "came across as another big company marketing document".

"WGAC is yet to see any evidence of a strengthened and improved approach to cultural heritage management. We have no visibility on the significantly strengthened internal practices, policies and governance that is referred to," Bevan said in the statement to Reuters.

WGAC was also concerned that the establishment of an advisory group could lead to standardised approaches that would not suit the needs of groups in the Pilbara like WGAC, he said.

The WGAC released a scorecard earlier this month that included metrics it wants miners to meet, including some around frequency and quality of communication.

Rio Chief Executive Jakob Stausholm told an investor call the company was committed to regaining trust and that Rio would make additional disclosures on its progress around heritage management.

Planned disclosures included measuring progress against the company's commitments, including better communication with traditional owners.

This included identifying how traditional owners' views would shape Rio's commitments, and their feedback on how Rio was performing, as well as increasing governance oversight.

Last year's destruction of the Juukan Gorge rock shelters in Western Australia for an iron ore mine sparked a massive public and investor uproar, leading to the exit of top executives and a pledge by the company to overhaul its approach.

Among other groups, Michael Woodley, Chief Executive Officer of the Yindjibarndi Aboriginal Corporation (YAC) welcomed Rio's push to leave a positive legacy.

The miner still needs a broader scope to drive self-determination to meet industry standards for monetary assessments and Indigenous water stewardship, he told Reuters.

Representatives from seven other Aboriginal Corporations did not have an immediate comment or did not reply to requests for comment about Rio's plans.

"Rio is at the start of a very long process of rebuilding trust," said Chief Executive Debby Blakey of Australian superannuation fund HESTA, which led a coalition of more than 20 Australian and international investor groups pushing for action.

"It will require long-term commitment to deep-seated cultural change and strong frameworks and processes in place to support genuine, open and ongoing partnership with Indigenous communities."

Rio has also agreed to advocate for industry-wide improvements. The miner said it would begin with interim reporting of these disclosures in the third quarter of 2021 and annually thereafter, along with periodic disclosure as appropriate. (Reporting by Melanie Burton and Rashmi Ashok in Bengaluru. Additional reporting by Sonali Paul. Editing by Shinjini Ganguli, Kenneth Maxwell and Michael Perry)