New geological data available from state, feds

DGGS and BLM publish airborne geophysical data for 600-plus square miles in Council, Paxson areas, industry interest elevated

Patricia Jones

PNA Contributing Writer

The state’s Division of Geological and Geophysical Surveys, working with funding from the U.S. Bureau of Land Management, is scheduled to release airborne geophysical data March 3 for more than 600 square miles in the Delta River mining area near Paxson.

“We expect a lot of interest,” said David Szumigala, senior minerals geologist at DGGS.

Located on the south flank of the Alaska Range, the Delta River mining area has already hosted significant exploration work by crews looking for platinum, he said. In addition, several tracts of land are being conveyed from the federal government to the state, adding to mining exploration interest in the area.

“Companies are slated to do a lot more work there,” Szumigala said. “We think it’s going to be a booming area.”

BLM paid about $300,000 to fund the Delta River mining area airborne geophysical surveys, conducted on about 350 square miles of land last summer. That data was combined with existing data BLM acquired for an additional 250 square miles of land. DGGS merged the two studies to produce comprehensive maps for the area, Szumigala said. “It was no trivial matter to merge the two data sets.”

Second release this year

Szumigala said a number of local miners and exploration companies working in the Nome area were extremely interested in the Council airborne geophysical survey, which covers 633 square miles. Sales of the state-generated data were “fair” on the release day, he said.

“Companies with properties in the area that are planning to drill this summer look at these maps to see if they want to change their targets,” he said. “Placer miners also see it as a way to get more exploration happening in that area. People in Nome are so pro-mining — they see it as a benefit to their community.”

The Council geophysical data show contrasts in magnetic and electrical properties of geologic units. The flight altitude (200 feet) and line spacing (one-quarter mile) yield very detailed aeromagnetic and resistivity maps, according to a DGGS news release. Szumigala discussed the Council data during the Feb. 14 meeting of the Fairbanks branch of the Alaska Miners Association.

A lot of anomalies

In addition, a known lode source — the now shuttered Big Hurrah mine — showed a distinctive signature or pattern on the geophysical maps. Similar geophysical signatures showed up in other areas of the Council survey, Szumigala said, providing potential exploration targets.

The state Legislature provided $500,000 to fund the Council survey. About 25 percent of that money has been set aside for crews to conduct geochemical and geological fieldwork in the same area, probably starting in 2004, Szumigala said.

“After each field season, that fall at the Alaska Miners Association meeting, we present our findings, then publish the related geologic maps the next summer,” he said. “We release the data as soon as we can put it together.”

Funding for the 2003 airborne geophysical program remains uncertain, Szumigala said. The state agency has nominated four to five prospective areas, forwarding that funding request to the governor’s office. The governor, along with the Legislature, can add or subtract from the agency’s proposal.

The state started funding airborne geophysical surveys in 1993, with the first maps published in 1994. So far, the state has funded surveys and follow-up ground geological and geochemical work on more than 8,500 square miles of land, spending $5 million to do so.

BLM has spent about $1.6 million to fly about 4,000 square miles of land in Alaska.

The total is “about 2 percent of Alaska,” Szumigala said. “It’s lots of square miles.”