A reconnassaince study of Rävliden VHMS-deposit, northern Sweden

• Main Author: Sidenmark, Jessica
• Format: Other/Unknown Material
• Language: English
• Published: Lunds universitet/Geologiska institutionen 2013
• Subjects: Skellefte district; alteration; VHMS; bedrock geology; Skelleftefältet; Rävliden; Earth and Environmental Sciences; Northern Sweden
• Online Access: http://lup.lub.lu.se/student-papers/record/3909860

In the Skellefte district today there are about 85 known VHMS-deposits, in the Kristinebergs area there are five known deposits, one of them being Rävliden. The supracrustal rock primarily consists of metavolcanic rock of rhyolitic composition and also metasedimentary volcanic rock. The district has gone through at least two metamorphic events. This resulted in the presence of large scale folding. Rävliden lies next to an antiform (compression N-S) that plunges to the west. In this study five drill cores from the Rävliden mine were logged. Six main lithologies were found; rhyolite, sandstone, graphite schist, sericite quartzite, tremolite skarn and carbonate rock. The logging of the five drill cores resulted in two profiles. The result is an interpretation of the geology, matching core with similar properties. In the sandstone there are areas locally rich in graphite which probably derives from sediment on the seafloor, the graphite schist is also probably seafloor-sediment. Alteration in the rock is extensive making it hard to see primary structures. The application of alteration index implies that the area is hydrothermally altered. This information and the findings of graphite imply that the area of study is in a transition zone between the footwall and hanging wall. It is also probable that the area is in a limb of an antiform when looking at the profiles. I Skelleftefältet finns idag runt 85 kända VHMS-fyndigheter, i Kristinebergsområdet finns fem av dessa fyndigheter, en av dem är Rävliden. Berggrunden består mestadels av meta-vulkaniter med ryolitisk komposition samt en meta-sedimentär vulkanisk bergart. Skelleftefältet har genomgått åtminstone två metamorfa event. Detta har resulterat i storskalig veckning av området. Fyndigheten i Rävliden ligger i närheten av en antiform (kompression N-S) där veckaxeln stupar till väster. Fem borrhål från Rävliden har karterats för denna studie. Resul- tatet av karteringen blev en framställning av två profiler. I dessa profiler beskrivs sex huvudsakliga litologier; ...