Plunging iron ore prices and a renewed focus on geopolitical tensions sent the ASX lower on Thursday, erasing around half the gains made earlier in the week.

The benchmark S&P/ASX200 fell 0.7 per cent to 5889.9 in broad-based losses, while the broader All Ordinaries index was 0.7 per cent lower to 5925.9. That drove the ASX to a small weekly gain, with the ASX200 up 0.5 per cent.

Weighing most on the index were the miners, after iron ore tumbled 8.5 per cent overnight. While iron ore futures did point to the metal recovering later in the day, it wasn’t enough to save Australia’s major resource companies, with the materials index weighing heavily – down 2.9 per cent – on the index.

BHP and Rio Tinto were 4.0 per cent and 4.4 per cent lower respectively. Pure-play iron ore miner Fortescue was savaged, falling 6.8 per cent.

Meanwhile gold miners, who’d already done well earlier in the week, posted the index’s largest gains. Northern Star Resources surged 6.8 per cent, Evolution Mining was up 2.9 per cent while Independence Group added 3.0 per cent. The All Ordinaries Gold Index rose 2.2 per cent over the week’s four trading sessions. 

Defensive buying could also be discerned in some of the ASX’s best performers on Thursday. Yield stocks like Sydney Airport and REA Group rose strongly, both up 1.9 per cent.

“There is a lot of risks out there at the moment and a lot of unknowns,” said Chris Conway, chief strategist and head of trading at Australian Stock Report. “Geopolitical tensions – Russia, Syria and North Korea – must be on investors’ mind at the moment.”

Not that investors should panic, he added. “At this stage, the current pullback looks like any other pullback we’ve seen over the past few months,”

“Such pullbacks have been greeted as a buying opportunity from the market.”