Mineraloške, petrološke i geokemijske karakteristike stijena sa živinom mineralizacijom na dijelu III horizonta u rudniku žive Idrija, Slovenija

master's thesis

• Title: Mineraloške, petrološke i geokemijske karakteristike stijena sa živinom mineralizacijom na dijelu III horizonta u rudniku žive Idrija, Slovenija : diplomski rad
• Title (english): Mineralogical, petrological and geochemical characteristics of rocks with mercury mineralization in the III horizon in Idrija mercury mine, Slovenia : master's thesis
• Author: Mariana Bal
• Mentor: Goran Durn (mentor)
• Committee member: Goran Durn
• Committee member: Stanko Ružičić
• Committee member: Uroš Barudžija
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mineralogy, Petrology and Mineral Resources); Zagreb
• Defense date and country: 2015-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology; Mineralogy and Petrology

Abstract

Cilj ovog diplomskog rada bio je napraviti geološku jamsku kartu dijela III horizonta u rudniku žive Idrija te
utvrditi mineraloške, petrološke i geokemijske karakteristike iskartiranih stijena. Tijekom izrade geološke karte
izuzeto je ukupno 10 uzoraka stijena i dva uzorka materijala iz rasjednih zona. Na tim uzorcima provedene su
mineraloške analize primjenom rentgenske difrakcijske analize, petrološke analize primjenom polarizacijskog
mikroskopa (mikropetrografska determinacija) te su analizirani glavni elementi, elementi u tragovima i rijetke
zemlje (REE). Primjenom polarizacijskog mikroskopa mikropetrografski su determinirani svi tipovi kartiranih
stijena i to: siltit do laminirani siltit/šejl, srednjezrnati pješčenjak tipa kvarcnog arenita, ranodijagenetski dolomit
tipa dolomikrit sa fosilima i tipa dolobiosparit, brečirani i metamorfozirani pješčenjak do milonitna breča i
brečirani ranodijagenetski dolomit. Glavne mineralne faze u uzorcima karbonskog škriljavca, gredenskog
pješčenjaka i bazalnog pješčenjaka su kvarc i kaolinit dok su tinjčasti minerali i pirit prisutni kao znatno ili malo
zastupljene mineralne faze. U uzorcima gredenskog pješčenjaka uz prethodno navedene mineralne faze kao
znatno zastupljena mineralna faza utvrđen je i dolomit. Ranodijagenetski brečirani dolomiti za razliku od
anizičkog dolomita kao malo zastupljenu mineralnu fazu sadrži i kaolinit. U rasjednoj zoni između gredenskog
pješčenjaka i anizičkog dolomita utvrđeni su gips i rozenit koji su nastali procesima trošenja primarnih
mineralnih faza. Mineralizacija sa cinabaritom nalazi se u: (a) rasjednim zonama, (b) na kontaktu anizičkog
dolomita i bazalnog pješčenjaka i (c) brečiranom ranodijagenetskom dolomitu. U uzorcima iz rasjednih zona
utvrđene su najviše vrijednosti za: Ba, Co, Ni, Rb, V, W, Mo, As, Cu,Pb i Zn. Uzorci u kojima je glavna sulfidna
mineralna faza cinabarit sadrže samo povišene vrijednosti As. Navedeno ukazuje na drugačiju mobilnost
elemenata uz rasjedne zone. Brečirani ranodijagenetski dolomiti imaju i do 10 puta veću ΣREE u odnosu na
anizičke dolomite. To jasno pokazuje da je tijekom mineralizacije došlo i do remobilizacije REE. U odnosu na
kompozit sjevernoameričkih šejlova teškim lantanidima obogaćeni su gredenski pješčenjaci, bazalni pješčenjaci
i svi uzorci dolomita. Za sada nemamo jasno objašnjenje zašto je u ovim stijenama došlo do obogaćenja na
HREE.

Abstract (english)

Abstract: The aim of this master thesis was to create a geological map of a section in the III horizon in Idrija Mercury
Mine and determine mineralogical, petrological and geochemical characteristics of the mapped rocks. During the
preparation of the geological map a total of 10 rock samples and two samples of material from the fault
zoneswere taken for further analysis. On these samples we performed mineralogical analysis using the X-ray
diffraction analysis, petrological analysis using the polarizing microscope (micropetrographic determination) and
analysed the main elements, trace elements and rare earth elements (REE). By using a polarizing microscope we
determined micropetrographic characteristics of mapped rock types as follows: siltstones to laminated
siltstones/shales, medium grained quartz arenite, early diagenetic dolomite which is classified as dolomicrite
with fossils and dolobiosparite, metamorphosed breccia sandstones/mylonite breccia and early diagenetic
dolomite breccia. The main mineral phases in samples of Carbon shale, sandstones and basal sandstones are
quartz and kaolinite. Secondary mineral phases in these rocks are micaceous minerals and pyrite. In samples of
Permian Groden sandstone in addition to above mentioned mineral phases we also found dolomite as a main
mineral phase. C ontrary t o A nizian dolomite, early diagenetic dolomitecontains kaolinite as a minor mineral
phase. In the fault zone betweenPermian Groden sandstone and Anizian dolomite we found gypsum and
rozenite; minerals that originated from weathering of primary mineral phases. Mineralization with cinnabar is
located in: (a) fault zones, (b) the contact zone between Anizian dolomite and basal sandstones and (c) early
diagenetic dolomite breccia. The highest value of Ba, Co, Ni, Rb, V, W, Mo, As, Cu, Pb and Zn were determined
in samples from the fault zones. We found increased values of As in samples in which the main mineral sulphide
phase is cinnabar. Above mentioned implies a different mobility of elements along fault zones.Early diagenetic
dolomite breccia has up to 10 times higher ΣREE compared to Anisian dolomite. This clearly shows that during
the mineralization there has been a remobilisation of REE. In relation to the composite of North American shales
Permian Groden sandstones, basal sandstones and all dolomite samples are enriched in heavy lanthanides. So far
we have no clear explanation why these rocks have been enrichedin HREE.

• Keywords: geološka jamska karta; mikropetrografska determinacija; mineralni sastav; geokemija; rudnik žive Idrija
• Keywords (english): geological map; micropetrographic determination; mineral composition; geochemistry; Mercury Mine Idrija
• Language: croatian
• URN:NBN: urn:nbn:hr:169:616382
• Study programme: Title: Geology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra geologije (magistar/magistra geologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2015-12-16 13:16:11