Summary of results. Re–Os molybdenite dating from the Hit or Miss deposit, Hatches Creek tungsten field, Warramunga Province

This Record details rhenium–osmium (Re–Os) dating of molybdenite separated from quartz veins associated with tungsten mineralisation at the Hit or Miss deposit of the Hatches Creek tungsten field, Warramunga Province. Two samples of molybdenite were collected from the former mine: sample FR17MVM001 as drill chips from a tungsten-mineralised quartz vein in drillhole HCRC021, and sample FR17MVM002 from a quartz vein in surface workings associated with tungsten and molybdenum. Molybdenite was dated to determine an absolute age for tungsten mineralisation at the deposit. The Re–Os molybdenite model ages obtained were 1677 ± 10 Ma and 1602 ± 9 Ma respectively. These ages are tentatively interpreted as mineralisation and/or remobilisation ages for molybdenum and tungsten, and the associated bismuth and copper at the Hit or Miss deposit; they also provide timing constraints on mineralisation in the wider Hatches Creek tungsten field. Low Re concentrations in the samples (1–2 ppm) are consistent with an evolved crustal source for the tungsten mineralisation. The older of the two Re–Os model ages is broadly consistent with previous age determinations for tungsten mineralisation and felsic intrusions in the Warramunga Province using Ar–Ar muscovite and U–Pb zircon dating methods. Although the geological significance of the new Re–Os molybdenite age is uncertain, the results are tentatively interpreted to record a protracted episode of tungsten, copper and molybdenum mineralisation in the Warramunga Province between ca 1700 –1600 Ma, associated with evolved felsic intrusions. BIBLIOGRAPHIC REFERENCE: McGloin MV, , Huston DH and Norman M, 2019. Summary of results. Re–Os molybdenite dating of the Hit or Miss deposit, Hatches Creek tungsten field, Warramunga Province. Northern Territory Geological Survey, Record 2019-010.