Dating of the Reocin MVT Deposit, Spain, by Paleomagnetism
Abstract
Located in the Basque-Cantabrian basin of northernmost Spain, the Reocin mine exploited one of the worldfs largest known Mississippi Valley-type (MVT) deposits (∼62 Mt at 8.7% Zn and 1.0% Pb) for >100 years. The sphalerite-galena and ferroan dolomite mineralization is in a karst system in 116±1 Ma Urgonian carbonates along the southeastern limb of the Santillana syncline that was formed by late Oligocene and mid Miocene pulses of the Pyrenean Orogeny. Paleomagnetic results from 22 sites (274 specimens) in ore-grade and marginal mineralization isolated a post-folding mid Miocene characteristic remanence (ChRM) direction. Mineral magnetics tests on mineralization, Zn concentrate and tailings show that the ChRM is carried both in sphalerite and ferroan dolomite by pyrrhotite mainly with minor magnetite. We suggest that the deposit was formed in the mid Miocene by fluids flowing from the Pyrenean highlands, ∼50 km SSW of Reocin, that scavenged the metals enroute to Reocin from the Paleozoic basement and/or Mesozoic clastic sediments below the deposit that were derived from the basement.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2009
- Bibcode:
- 2009AGUSMMA73C..03S
- Keywords:
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- 1527 Paleomagnetism applied to geologic processes;
- 3665 Mineral occurrences and deposits;
- 8108 Continental tectonics: compressional;
- 9335 Europe;
- 9605 Neogene