Journal of Geosciences, 64 (2019), 179–195

DOI: 10.3190/jgeosci.291

Original paper

Boudinage arrangement tracking of hydrothermal veins in theshear zone: example from the argentiferous Strieborna vein(Western Carpathians)
Stanislav JACKO1*, Roman FARKAŠOVSKÝ1, Julián KONDELA1, Tomáš MIKUŠ2, BarboraŠČERBÁKOVÁ1, Diana DIRNEROVÁ1
Technical University of Košice, Institute of Geosciences, Letná 9, 040 01 Košice, Slovakia; stano.jacko@tuke.sk
Slovak Academy of Sciences, Earth Science Institute, Ďumbierska 1, 974 01 Banská Bystrica, Slovakia*
Corresponding author
1
2

Argentiferous Strieborna vein of the Rožňava ore field occurs at the southwestern margin of the Gemeric Unit (Slovakia).
The hydrothermal mineralization of the vein closely related to the Early Cretaceous tectonometamorphic shortening of
the Western Carpathians. For their emplacement, the vein used the steeply dipping, fan-like cleavage and dislocation
set of the Alpine regional structure. Successively the vein was integrated into the sinistral transpressional regime of
the Transgemeric shear zone. A polyphase vein filling comprises Variscan metasomatic siderite remnants and the Early
Cretaceous syntectonic hydrothermal mineralization, the latter consisting of two mineralization phases, quartz–sideriteand quartz–sulphidic. During Cretaceous shear zone transpressional events, the vein was segmented into five individual
bodies and redistributed to kinematically and geometrically different tensional and compressional boudins. The vein
asymmetry increase, different vertical mineralization content and spatial distribution of mineral phases representing
individual mineralization periods directly relate to a rheological contrast between the vein and surrounding rocks stressand pressure shadows distribution. The actual form and distribution of the Strieborna vein segments is the product offour boudin evolution stages: (1) pre-deformation, (2) initial, (3) boudin-forming and (4) boudin-differentiation stage
that controlled vertical mineralization distribution. The sulphidic mineralization is dominated by two generations ofargentiferous tetrahedrite and two youngest sulphosalts associations enriched by Sb and Bi. The youngest sulphosaltsof the stibnite phase at the Strieborna vein resemble contemporaneous mineral associations at the nearby Čučma stibnite vein lode. Both vein occurrences located within the Transgemeric shear zone belong to the Rožňava ore field andthey are cut by the same diagonal strike-slip fault. These analogies indicate a similar genesis of terminal associations at
both these vein deposits. Results of the Strieborna vein sulphosalts spatial analysis confirm their vertical zonation. The
Sb and Ag contents decrease, while Bi contents increase, with depth and conserve boudin evolution stages created in
distinct rheological environments. The vertical boudin arrangement concentrates economically most prospective parts
into asymmetric boudin tension shadows.
Keywords: boudinage, transpressive shear zone, hydrothermal mineralization, rheology, deposit, Western Carpathians
Received: 30 November 2018; accepted: 23 October 2019; handling editor: J. Zachariáš

1. Introduction
Vein-type deposits overprinted by later shearing represent
infrequent type of economically mined deposits in theworld. Scanty resources, structural redesigning, mineralization heterogeneity and exploration costs drifted the shearzone deposits outside of economic interest. However, somemarkedly sheared and boudinaged gold (Baker et al. 2002;
Smith et al. 2013; Martins et al. 2016) or iron (Roache
2004; Rajabzadeh and Rasti 2017) deposits are/were profitably mined. Structural research and understanding of theshear zones in the economically potential areas may affectthe mining exploration as well as increase the quality andquantity of raw materials in the heterogenic structural space.
The Rožňava ore field (ROF) comprising polymetallic Maria vein and argentiferous Strieborna veincovers a southern part of the Western Carpathian Gemeric basement (Fig. 1) and is a good example of sucha mineralization type. The Strieborna vein is similar tothe subparallel Maria vein, situated only 600 m to the
NW and historically mined for Cu and Sb. Both veinsdiffer mainly structurally; whilst the Strieborna vein issegmented into boudins (Fig. 2a), the Maria vein is arelatively continuous unsegmented body. Basement suitesof this area are penetrated by subparallel hydrothermal
siderite–quartz veins generally of the NE–SW trend.
Their terminal evolution related to the Transgemericshear zone (TGSZ) activity having the same direction
and amplitude of several km.
Strieborna vein represents significant and recently
one of the most valuable ROF vein ore bodies situatedat the TGSZ. The vein occurs within two rheologicallywww.jgeosci.org

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

different Early Paleozoic rock sequences controlled by
a competence contrast, i.e. in between brittle-deformed
meta-pyroclastics underlying the vein, and ductiledeformed phyllites forming the vein’s hanging wall(Fig. 2). The Strieborna vein shows a record of multiple
epigenetic hydrothermal processes (Sasvári and Maťo1998; Hurai et al. 2002). The oldest one, consistingof nearly monomineral siderite infilling (medium- tocoarse-grained siderite), dominates over the succeeding
quartz–sulphidic phase. The first period of the quartz–
sulphidic phase comprises Ag-tetrahedrite, chalcopyrite,
pyrite, arsenopyrite and first sulphosalts association of

the tintinaite–kobellite series, Bi-jamesonite-bournonite,
and tetrahedrite (from the oldest to the youngest phase).
The second period contains younger sulphosalt association represented by chalcostibite–berthierite–garavellite
series that unambiguously post-dated the Ag-tetrahedrite.
Bi-stibnite, Sb-bismuthinite, and native Bi-stibnite precipitated only at the closure of this second period of thequartz–sulphidic mineralization phase (e.g., Varček 1963,
1973; Jeleň in Mesarčík et al. 1991; Grecula et al. 1995;
Sasvári and Maťo 1998; Mikuš et al. 2018 and references
therein).
This study focuses on the variable boudinage development of the Strieborna vein in
Cracowrheologically contrasting parental
N
D
or
AN
th
POL
-E
rocks. It aims to identify developur
opOument of boudin structures based
te
U
ea
rW
K
Westernn
on the analysis of their geometry
R
Carpath
es
A
ians
P
te
IN
rn
and the structural patterns of the
Ca
E
rp
at
boudin bodies. Moreover, it alsohiansconstrains temporal and spatial
Ea
ste
rn
evolution of ore phases throughC
Budapest
inout the process of vein boudinage
s
a
nB
onia
Pann
deformation.
HUNGARYala

Vienna

tf

o

rm

ps

n

Al

IA

R
ST

s

thi
pa

Ea

ar

r
te

s
an

AU

Outer Flysch belt

OWC

2. Geological setting

Neogene sedimentary rocks
Neogene volcanics

IWC

Southern

Inner Carpathian Paleogene basin

ROMANIA

Pieniny Klippen Belt

PKB

buried Neogene volcanic rocks

AKIA
SLOV

inner units of Carpathians

b

SV

Z

LS

Ge

m

c
eri

Su

SZ

Z
GS

KošiceTRožňava00100

200 km

M

nit

ru

pe

Z

DS

ns

Carpathia

50 km

TGSZ Transgemeric shear zone
DSZ Dobšiná shear zone
LSZ Lubenicka shear zone
MSZ Margecany shear zone
SV Slaná Valleyc
Dobšinná

er

em

sg

n
Tra

e

on

rz

ea

h
ic s

KošiceRakovec Unit
Gelnica Unit
Meliata units

180

Gemeric
SuperunitRožňava

Klatov Unit

The Rožňava ore field is locatedin the Gemeric belt (the GemericSuperunit of Plašienka 1999;
Bezák et al. 2009) of the Western
Carpathians. The southwardly
adjoined basement represents an
Early–Late Paleozoic megastructure of the Alpine–Carpathian
chain. With respect to the paleogeography and present tectonic
position, it is the southernmost
unit of the Western Carpathians(Andrusov 1968) formed at thesouthern edge of the Variscan
Orogen. The basement of the
Gemeric belt, derived from the
Meliatic suture zone (i.e., a rem-

Neogene sediments
Faults, thrusts
Study area

Fig. 1a – Location of the study areain the Western Carpathians. b–c – The
Gemeric belt (also called the Slovak Ore
Mountains) bounded and segmented byseveral shear zones modifying (namely
at the Transgemeric shear zone section)
the internal structures. Associated hydrothermal vein systems concentrate along
the shear zone. The Strieborna vein is
located near the Rožňava town (marked
by the red frame).

Boudinage of hydrothermal veins in the shear zoneab

W
NE in V
ud
Bo

Bo

ud

in

IV

67
2
1
4
3 10 98mine gallery

rediscovered vein

vein

fault

in

eb

ss

-c

ut

Čučma

u

Strieborna
vein

Pallag
vein

SE

400
mininglevel:

200

6

0

10

8

M
ár
ia
Tri vrchy
1
45
7
892
6
3

in

Mayer
vein

ve

Mária
vein

ve
in

1 23
10
7 89
4 56

a

Bo

rn

[a.s.l.] Aurélia lower
vein
NW

57
83
94

7 43
10
2985

II

Boudin I

600

1

bo

S

ro

6

rie

150 m

din

C

6
9
1
534
10

St

tri

ve

1
62

2
7

III

Transgemeric shear zone

0

na

or

n

di

u
Bo

8

5

13

–200

Rožňavazone of strong shear deformation
0

0

750 m
874
5
2916
10
3

500 m

conglomerates

meta-pelites

dark metapelites
in metapsamites

meta-psamites withmeta-pelites

meta-psamites

veinscross-section

meta-pelites withmeta-psamites

meta-pyroclastics ofporphyroclastic texture

shear zones and faults

boreholes: negative (blue)
positive (red)old mines

Fig. 2a – Map of the Strieborna vein at the 10 mining level. b – Geology of the study area (after Grecula et al. 2011) exemplifying link of theore veins to lithological boundaries and assumed TGSZ/cleavage directions. Similar relations show sharp ore veins and faults inclinations. Notecommon country rocks and setting of the Strieborna and Mária veins, as well as the nearby Čučma Sb vein, located at the same, steeply dipping
N–S fault transecting the TGSZ course. The NW–SE cross-section reflects an influence of rock lithology vertical distribution to veins lateral andvertical morphology in the shear zone.
thnant of the Meliatic Ocean trough), comprises four
steeply southward dipping tectonic units. These are, from
north to south, the Rakovec, Klatov, Štós, and Gelnica
units – several authors also use the term “groups”. They
consist of Early Paleozoic to Late Carboniferous lowgrade metasedimentary and metavolcanic rocks (Bajaník
et al. 1983; Vozárová et al. 2016). Only the pre-Viseangneissic–amphibolitic Klatov Unit sheet forms an exception. Intrusive Permian/Triassic bodies of the Gemericbelt – only cropping out in the Gelnica Group – occupy
the southernmost part of the belt belonging to the specialized S-type granites enriched mainly of B and F volatiles(Finger and Broska 1999; Poller et al. 2002). Structurally,
the Gemeric belt consists of southward-dipping nappe
sheets that evolved initially from Variscan fold structures(Rozložník 1976; Grecula et al. 1995). Broadly preservedcleavage sets transposing primary foliation of the basement rocks belong partly to Variscan structural remnants(Grecula et al. 1995; Faryad 1995; Lexa et al. 2003), or
to the Alpine shortening results (Maluski et al. 1993;
Dallmeyer et al. 1994) as they occur in both Late Paleo-zoic and Mesozoic cover formations (Jacko and Sasvári
1990; Plašienka 1999; Németh 2002). Also, regionallysignificant shear zones of NE–SW and NW–SE directions
cutting either basement or Mesozoic formations belong
to the Alpine origin.
Early Paleozoic volcano-sedimentary, low-grade Gelnica Group itself is divided into three (Vlachovo, Bystrý
potok, Drnava) formations (Bajaník et al. 1983; Vozárová
and Ivanička 1996). Only the last of them is present in the
ROF area. During Variscan and Alpine regional metamorphism, the Gelnica Group sequence was metamorphosed
under lower greenschist conditions to variously coloured
phyllites, metasandstones/metagreywackes, crystalline
limestones and metavolcanic rocks only (Faryad 1991,
1995; Vozárová 1993).

3. Methodology
The structural analysis of the Strieborna vein was realized
at the surface as well as in the underground. Authentic
181

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

information about the adjoining, parallel and, most
likely, genetically connected Mária vein (Mesarčík 1994;
Grecula et al. 1995, 2011; Sasvári and Maťo 1998) was
also taken into consideration. In order to decipher the
structural evolution, the cross-sections of both mentioned
lodes have been correlated, namely at well-explored 13th(170 m b.s.l.), 10th (20 m b.s.l.), 9th (30 m a.s.l.), 8th (80 ma.s.l.) and 6th (180 m a.s.l.) mining levels (Fig. 2). The
Strieborna vein itself was systematically surveyed at five
underground mining levels (i.e. at 13th, 10th to 8th). Geological structures were also correlated with controllingaudio-frequency magnetotelluric source at higher spectral
bands (~1 Hz to 80 kHz) signal.
Boudins geometrical classification is based on Ramsay
and Huber (1987), Hanmer and Passchier (1991), Goscombe and Passchier (2003), Goscombe et al. (2004),
Rodrigues et al. (2016) and extended by parametersdescribed by Samanta et al. (2017). The structural reinterpretation of the vein evolution at the 6thmining level,
analysis of inter-boudin zones to boudins bulk deformations were based on Passchier and Druguet (2002),
Dabrowski and Grasemann (2014) and post-boudinage
plastic deformations due to strain softening according to
Lloyd and Ferguson (1981), Ghosh and Sengupta (1999),
Passchier and Trouw (2005), Rodrigues and Pamplona(2018). We compare surface structural data with the orevein mineralization distribution and structural pattern of
the Strieborna vein ore body. The vein was additionallysurveyed at two (6th and 10th) sublevels, two raises, 13
underground and one surface drill hole.

a

b

0

c

Sd

5 cm

4. Results

4.1. Structure and lithology
The Drnava Fm. rock sequences (Fig. 2) show NE–SW
direction and generally moderate SE inclination of thestructural planes. They were deformed by the Transgemeric shear zone (TGSZ) of the same direction in thestudied area. The Rožňava ore field rock suites, including mineralized veins, were incorporated into the TGSZ
structural pattern. Ore veins of the studied area weredeveloped within metapsammitic rocks of the Drnava
Fm. that are irregularly intercalated by dark metapelites
with tiny conglomeratic and carbonate layers (Fig. 3).
All mentioned rocks were metamorphosed at greenschistfacies conditions (Faryad 1991, 1995; Vozárová 1993).
The Strieborna vein is best developed in the rheologically competent metavolcanic and metapsammitic rocks(Fig. 3). If hosted by phyllites, the vein course and thickness reduce substantially.
Metavolcanic rocks are foliated, originally aphanitic
pyroclastics of rhyolite composition, formed mainly byquartz and white mica. Sporadic small-scale compositional layering (up to 1 m thick) or banding is typical ofthese rocks. The younger association, rimming mainly
exocontact of the Strieborna vein, consists of newly
formed hydrothermal minerals comprising quartz, siderite,
pyrite, and pyrrhotite. At the vein’s footwall occur also
porphyric rocks. They contain quartz and, rarely, feldspar
porphyroclasts reaching on average up to 5–10 mm insize. From the base to the top,
metavolcanic rocks pass throughthe metapsammitic rocks up tophyllites (Fig. 2). The contact
between these three rock types
is of discrete character.
Metapsammites of the studied area belong to two lithologi0
5 cm
cal groups, quartz arenites/ graywackes and lithic arenites/lithic
wackes. The most common are
Sd
the lithic metagreywackes. Re-

Po
0

5 cm

d
Po

Sd
0

182

5 cm

Fig. 3 Core samples from the exploration borehole drilled in the study
area. a – Brittle–ductile deformationof fine- to medium-grained light grey
metagraywacke interbedded with thedark grey phyllite. b – Prolonged lensesof light grey metagreywackes alternating with dark grey phyllites. c – Brittle
deformation of siderite (Sd) veins in
the metagraywacke medium. Somebrittle fractures are filled by pyrrhotite(Po). d – Boudinaged siderite vein.
Surrounding vein fractures are filledby pyrrhotite.

Boudinage of hydrothermal veins in the shear zone
Foliation shear zone N
Datasets: 22

she

ar b

and

Foliation SE edge
Datasets: 16Na
Foliation NW edge N
Datasets: 31

Transgemeric shear zone
Mária Vein
Strieborna Vein

Surface

Folia

tion

NW

SE
0

Boudins

Transgemeric shear zone

Silver Veinb

Mária Vein

Fold axis

elevation ASL [m]Geophysical cross-section
localization (Fig. 4b)

600 m

distance [m]Fig. 4a Structural position of the Strieborna and Mária veins in the Transgemeric shear zone and foliation course distribution in the neighbouringrock segments. Contour diagrams from different parts of Transgemeric shear zones confirm shear band flexure in the middle segment of the studied
area. b – Geophysical interpretation of auditing audio-frequency magnetotellurics source (CSAMT) supports similar anomalies at the mined (Mária)and surveyed (Strieborna vein) parts and inclined geological structure of transversal NW–SE cross-section.

garding granularity, they could be interpreted as poorly
sorted, medium- to coarse-grained metapsammites. The
dominant constituent of these rocks is quartz, where therelationship between prevailing grain size and the grain

roundness is evident. The fine-grained rocks show a better
sorted clastic material and more rounded quartz grains thanthe coarse-grained metapsammites. Lithic fragments andfeldspar clasts reach also a substantial amount.
183

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerováb

360m a.s.l.

On the surface

a

0

1.5 m

c
d

Strieborna
veinBelow the surface

20m b.s.l.

cross-section

Strieborna vein

Fig. 5 Comparison of structural patterns (elevation 400 m) between surface and underground. a and c – Limb amputation of fault-related folds
parallel with Transgemeric shear zone. b and d – Compressive asymmetric boudin bodies developed across the vertical profile of the shear zone.
Note the quartz ladder filling the boudinaged quartz–siderite veinstone.

Grey to black phyllites form up to 10 m thick layers in
the metapsammitic rocks. In detail, they exhibit banded
structure due to the rhythmic alternation of light-grey anddark-grey bands. The dark colour is associated with highorganic carbon content. The rocks are composed mainlyof white mica and quartz, chlorite is subordinate.

4.2. Cleavage and folds
A typical feature of the Gelnica Group rocks is a steep
cleavage set that relates to area shortening. Early Cretaceous tectonometamorphic processes (deformation stage
AD1 sensu Németh et al. 1997) formed an asymmetricpositive fan structure across the entire length of the Gemer belt (Lexa et al. 2003). Intensively sheared rocks of
the Rožňava ore field show changes in the cleavage orientation; analogically the Strieborna vein changes its strikefrom the SW to the NE. It means that the Strieborna vein
is a curved structure in the studied area, which was proven by many structural measurements and by the position
184of the positive boreholes (Fig. 2b). In the studied area,
the SW–NE orientation of the cleavage strike lines in thesouth changes to the SSW–NNE and, finally, SW–NE
direction in the north (Fig. 2b). In the transversal verticalcross-section, the originally moderate cleavage inclination gradually steepens (Figs 2 and 4). The south-easternedge of the area is characterized by open shear folds andsteeply dipping NE–SW directed cleavage. A progressive
structural evolution, caused by shear strain, successivelytransposed Alpine folds into a position parallel to thecurved structure of the Gemeric belt. Consequently, foldaxes orientation varies between SW–NE and SSW–NNE,
depending on their position in the above-mentioned bent
structure. Typical are close folds with similar 2 foldshapes (Ramsay and Huber 1987). They usually have
one limb cut as a result of transpressive shear movements(Fig. 5). An average fold amplitude at the shear zone
varies from 0.5 to 2.0 meters (Fig. 5). The axial planecleavage shows NE–SW strike lines orientation and, ingeneral, SE inclination. The stretching lineation on theBoudinage of hydrothermal veins in the shear zone

dark phyllite
Qtz
Qtz
asymmetricobjects

sh

ea

rb

an

d

Qtz
Qtz

dark phyllite

fold

sh

ea

dark phyllite

rb

an

d

0

0.3 m

Fig. 6 Tightly folded dark phyllites interbedded with hydrothermal quartz layers, deformed by the strike-slip shearing parallel to NE–SW Transgemeric shear zone course, the roof of the 6th mining level. Strike-slip deformation is visible in shearing of folded pre-quartz–siderite hydrothermal
quartz veins. Quartz layers shear bands show monoclinic fabric symmetry and sharp-tips oriented to TGSZ shear zone direction.

cleavage planes dips moderately towards the S to SSW.
The fold axial cleavage planes are frequently injected byhydrothermal quartz veins. They are well-identified in
the adjacent fold limbs, mainly at rheological boundaries
between slates and hydrothermal quartz filling.

4.3. Boudinage
Nicely preserved Strieborna vein boudins occupy a depth
interval between 6th and 10th mining levels, forming fiveboudin bodies here (Fig. 2a). Their length varies fromseveral tens to more than 100 m. They originated along
two dislocation sets filled by mylonites of m–dm thickness. The more frequent set of the NNE–SSW direction
with subhorizontal striations is passing parallel to theRožňava–Čučma village fault. The second set of subvertical fault planes shows NE–SW orientation (Figs 2 and 4),
and inclination to SE. Structural data indicate that theprocess of the Strieborna vein boudinage closely related
to the strike-slip activity of the mentioned fault sets. The
Strieborna vein and the Čučma stibnite vein recline at
the same NNE–SSW fault structure and they contain thesame mineral associations of the quartz–sulphidic phase(Grecula et al. 1995; Sasvári and Maťo 1998; Mikuš et al.
2018). They probably underwent a similar hydrothermal
evolution during the final steps of vein formation.
The brittle–ductile mylonitic shear zone up to 1 m thickruns near the Strieborna vein at 6th mining level, parallel
to foliation in the metapelitic rocks. The dark phyllites
enclose lenses of white hydrothermal quartz with variable
lengths and visible signs of shear deformation. They aresegmented by shear bands, or they form boudins, asymmetric objects, and remnants of isoclinal folds (Fig. 6).
The minor veins, several cm–dm thick and segmented
most often to boudins, occur close to the main vein body(Fig. 7). They are parallel to the cleavage of surrounding
metapelites as well as parallel to the Strieborna vein andthey are formed by siderite and quartz. The minor veins
can be also deformed by shear bands or folded (Figs 6–7).
Based on the kinematics (sensu Goscombe et al. 2004),
the minor boudins can be divided into two types: those thatare segmented by shear movements (Fig. 7) and those, theorigin of which relates to tension deformation (Fig. 9a).
According to the boudin geometry, they can be divided
into three main categories. Asymmetric shear band boudins
have boudin blocks separated by shear planes (Figs 5, 7).
185

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

quartz boudinsideriteboudinshear band on
inter-boudin
planemetapelite

siderite boudininter-boudin zone
filled by quartz
inter-boudin zone
filled by quartz
siderite boudinsiderite boudin

metapeliteinter-boudin zone
filled by quartzashear band on
inter-boudin
plane

quartz boudinbFig. 7 Asymmetric shear bands at inter-boudin plane filled by brown siderite and light quartz. a – Strongly compressed homogeneous siderite
boudins delimited by straight shear planes with conical quartz tails formation. b – Lens-like distribution of sideritic and quartzose boudins, divided
by shear band inter-boudin planes resulting from shear deformation of relatively much more thickened ductile phyllite surrounding.

The boudin blocks are formed mainly by siderite, less by
quartz (Fig. 7a–b). The inter-boudin zone is filled by quartz
or by surrounding metapelitic rock. In some cases, the terminal parts of the shear band boudin blocks were dragged

Qtz

Sd
Qtz

Qtz
Sd

in the direction of the boudin separation and form drawn
boudins. The boudin blocks of the symmetric torn boudins
are formed always by siderite and inter-boudin zones arefilled by quartz (Fig. 9). The siderite in the boudin blocks
is brittle deformed. Single grains are separated from eachother or they are fractured along their cleavage planes. The
open space among the separated parts of the siderite grains
is filled by quartz (Figs 8, 9a–b). Various microstructural
markers were observed in torn boudins, previously unknown from the ROF area (Fig. 9b–c). Pressure markers
like tapered stylolite teeth (Fig. 9c) and stylolitic joint surfaces indicate maximal compressive stress oriented perpendicularly to the foliation. The minor siderite veins deformed
as a brittle material set in the more ductile metapelites. The
foliation planes of the surrounding metapelites are bent
around the boudin structures (Figs 7a–b, 9a).

5. Discussion
1 mm

Fig. 8 Microscopic view of sharp siderite boudin margin and interboudin quartz filling. Siderite (Sd) limited via straight planes shows
distinct deformation cleavage. Younger, post-deformation quartz (Qtz)
injection replaced siderite open fracture conformably to rhombohedral
siderite cleavage planes.

186

5.1. Structural coherence
The structure of the Gemeric belt reflects the impactof several Variscan and Alpine deformation events

Boudinage of hydrothermal veins in the shear zoneastretching lineation

Sd

Qtz

inter-boudin zone
filled byquartz veinboudin block formed by siderite
mineralization
0

2 cm

sideriteboudin
block

b
Qtz

Qtz
Qtz

Qtz
Qtz
Sd

0

Sd

Sd
Sd

3 cm

boudin block formed by fractured siderite, fractures are filled by quartz

c

open

open space

stylo

lites

0

tens
ion f

spac

e

stylolites

ractu

res

surface stretching lineation

tension strain
subgrains rotation
stylolites

3 cm

Fig. 9a – Symmetric torn boudins filled by siderite and younger quartz mineralization. b – Cleavage planes and siderite tensile fractures filled byyounger hydrothermal quartz. c – Tensile boudin internal structure composed of several structural elements, i.e. responded paleostress marked bystylolites and tension fractures. Boudinal stretching also allowed subgrains rotation into paleostress-free boudin segments.

(Rozložník 1976, 1980; Maheľ 1986; Faryad 1991;
Plašienka et al. 1997; Grecula et al. 1990, 2011 andreferences therein). The Variscan pervasive fold structure of the superunit, accompanied by greenschist-facies

metamorphism, and following nappe formation, have
prepared the regionally penetrative planar set for thesubsequent Alpine structural and metallogenetic processes.
187

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerováa

EARLY–MIDDLE JURASSICSLATE JURASSIC–EARLY CRETACEOUS

N
ADRIA

S

VEPORIC+++

MeltingbTransgemericshear zone
BOUDINAGE

ADRIA

Klatov Unit

Hronicum

Rakovec Unit

MineralizationN
VEPORIC

Gelnica Unit
Meliata units

Fig. 10 Transition from divergent to convergent regime in the southern part of the Western Carpathians. a – Delamination of the Meliata Unit troughby dominant listric fault. Heavy oceanic core and deep sediments were dragged underneath the Gemeric Unit domain. Melting of underthrusted
rock complexes enriched hydrothermal solutions by elements like Mg, Fe, Sb, Bi, Ag or Au. b – Collision processes (AD1 tectonic phase sensu
Németh et al. 1997; Lexa et al. 2007) transformed antithetic faults into north-vergent imbricate structures and initiated the Alpine shortening history of the Western Carpathians.

The Western Carpathian Alpine shortening initiation(Fig. 10) basically related to the closure of the Late Jurassic
Meliata trough, and consecutive thrusting of its successions
over a southern part of the Gemeric Unit at c. 160–150 Ma(see also Dallmeyer et al. 1996; Faryad and Henjes-Kunst
1997; Plašienka 1999 and references therein). Variscan
structures of the Gemeric domain have been throughout thefollowing Cretaceous events either accentuated or substantially reworked. Consequently, the origin and subsequentdevelopment remain frequently unclear.
The Early Cretaceous onset of the Western Carpathiancollisional wedge formation is supported by the40Ar–39Ar
dating yielding ages of c. 140–100 Ma for white micas
growing in penetrative foliation planes developed inburied Veporic basement complexes or in their Permo/
Triassic cover (Maluski et al. 1993; Dallmeyer et al.
1996, 2008). A terminal part of this event is also considered as minimal interval of the Gemeric Unit thrusting
onto the northern Veporic block (e.g. Plašienka et al.
1997; Plašienka 1999; Schulmann et al. 2005; Putiš etal. 2009; Grecula et al. 2011). Continuing progradationof the Western Carpathian wedge (at c. 100–90 Ma) resulted in cover nappes emplacement (e.g. Plašienka et al.
1999; Putiš et al. 2009) succeeded by the pre-Turonian
extensional and heterogeneous exhumation of the Veporic and Gemeric units (Putiš et al. 2009). This event
caused large-scale open folding followed by the creationof steeply dipping, fan-like axial cleavage set and faults
formation either in the Gemeric realm, adjacent Veporic
Unit or in overthrust Hronic cover nappe pile (Jacko
1979; Reichwalder 1982; Rozložník 1984). Steeply inclined soles of the Variscan thrust sheets and fold axial
fan-like cleavages/faults of the units, frequently used as
metalliferous structures, have been afterward spatiallyincorporated into the pre-Paleogene Gemeric shear zonesof the NE–SW and NW–SE direction.
The Gemeric Unit shear zones (Fig. 1b–c) reaching
several km amplitude, consist basically of sub-parallel
188

strike-slip faults which significantly transform and rhythmically cut off the former Variscan and Alpine structures.
Deforming them at simple shear brittle–ductile conditions(Grecula et al. 1990; Sasvári and Maťo 1998), they markedly modify an initial structural pattern including original ore vein distribution of the Gemeric Unit. Internal
structures and shear zones dimensions were subsequently
overprinted by several repeated Tertiary tectonic events.
The Transgemeric shear zone (TGSZ, Grecula et al.
1990) cutting the Gemeric realm axially in NE–SW
direction (Fig. 1) consists of numerous steeply dipping
sinistral strike-slips spreading at 2–3 km amplitude.
The TGSZ that is 80–120 km long comprises numerous ore veins of the Gemeric belt including those of theRožňava ore field (ROF, Figs 2, 4). The TGSZ structuralevidence testifies both prolonged kinematic evolutionof the zone and close relations to multi-phase formationof the Strieborna vein (see Grecula et al. 1995; Sasvári
and Maťo 1998; Hurai et al. 2008). Shear deformationof different magnitudes led to a multiple shearing of therock sequences, ore veins boudinal segmentation and/or
contemporaneous redistribution of the latest phases ore
mineralization within the Strieborna vein (Figs 2, 5, 6).
From a comparison of analogous structural evolution andsimilar low-grade metamorphic conditions of the Gemericand Veporic units seems to be obvious that the Early
Cretaceous (c. 75–85 Ma) interval could be regarded as
onset of the TGSZ transpressional deformations (Huraiet al. 2008).

5.2. Metallogenic problems
Distinct remnants of metasomatic siderite bodies clearly
replaced by hydrothermal quartz–siderite assemblage are
known from deep mining levels of the Rožňava mine, as
well as from other Gemeric veins. This suggests that atleast some carbonate inlayers of the Drnava Fm. weremetasomatized prior to the formation of Early CretaceousBoudinage of hydrothermal veins in the shear zone

Cataclasis

Shortening

Shortening

VerticalStrechingFig. 11 Successive scheme of the Strieborna vein hydrothermal mineralization
with prevailing deformation processes(according to Sasvári and Maťo 1998;
Mikuš et al. 2018).

Cinnabar
Marcasite
BorniteCovelline
Hematite
Dolomite
Calcitefrom Divergence to Convergencefrom Divergence to Convergencevein-type mineralization in the Gemeric belt. One of the
Faryad and Henjes-Kunst 1997; Dallmeyer et al. 2008).
key metallogenic problems of hydrothermal mineralizaEven the southern rim of the Gelnica Group, directlytion in the Gemeric Unit is the source of Mg, Fe and otheradjacent to the Meliatic Ocean eastern border, was likely
metallic elements that are present in hydrothermal veins.
underthrusted as early as at the onset of the crustal subGrecula et al. (2011) solved this issue through percoladuction (172 Ma, e.g. Faryad and Henjes-Kunst 1997).
tion of fluids released from the precursor rocks (namely
Thereafter, throughout the Early Cretaceous syntectonic
black schists and bimodal volcanites), either during theperiod, mobilized mantle/crustal fluids infiltrated into
Variscan low-grade metamorphism or during the Alpine
penetratively prepared structures of the Gemeric Paleogreenschist-facies retrograde overprint. Also, Hurai et al.
zoic rocks, precipitating siderite hydrothermal mineral(2008) reached a similar conclusion, i.e. that ore fluids
ization. This idea is supported by the large amount of
parental to the Gemeric siderite veins had to be enriched
mantle ultrabasites in Meliatic nappes overriding the Gein Fe and Mg through their interaction with underlying
meric Paleozoic basement and by extensive siderite veins
Paleozoic metabasites and volcaniclastics. Lexa et al.
accumulation in the Gemeric belt basement, compared to(2007) and Németh et al. (2016) invoked rather fluid conthe northern Western Carpathian basement complexes.
vection due to overheating associated with Late Variscan
post-collisional mantle upwelling and crustal thinning.
5.3. Formation of the Strieborna vein
Rozložník (1990) reminded two essential problems
quartz–sulphidic phaseregarding siderite hydrothermal mineralization in theWestern Carpathians: first – it is bound to pre-Mesozoic
Both shearing and boudinage events separated the StrieborInner Western Carpathians units and extreme accumuna vein quartz–siderite phase from the quartz–sulphidic
lation of siderite in the Gemeric belt in excessively
one (Fig. 11). Ag-enriched tetrahedrite and other minershortened Early Paleozoic complexes, and second – a
als precipitated during the first and second periods of thepresence of an extensive “mantle metals” signature inquartz–sulphidic phase. Diagonal tetrahedrite veinlets
these hydrothermal veins. He sought the source of metals
in siderite lodge and broad molten tetrahedrite clusters
in the Pieniny Klippen Belt basic/ultrabasic mantle rocks
enclosing siderite fragments (Fig. 12) unambiguously
underthrusted below the entire Inner Western Carpathdocument position of tetrahedrite in the mineral succession
ians units in Cretaceous times(Rozložník 1990, Fig. 5).
Phase
Quartz–Siderite
Quartz–sulphide
All the above-mentioned auRejuvenization
Periods
QuartzSiderite
First
Secondthors put the onset of siderite
BoudinTectonic
Veining
Veining
Boudinage
vertical stretching
eventsvein formation into the synQuartz
orogenic Early Cretaceous interval. In the studied area, this Siderite
Turmaline
is confined by the 124 ± 1.7 Ma Sericite40
Ar– 39Ar age of muscovite– Magnetite
phengite concentrate from the Pyrite
Maria vein quartz–tourmaline Pyrrhotite
Sphalerite
phase (Hurai et al. 2008).
GalenaWe also assume an initial Arsenopyrite
mobilization of metals owing Tetrahedrite
to mantle assistance. However, Chalcopyrite
Tintinaite
in regard of above-mentioned, Kobellite
we tend to seek an initial source Bi-Jamesonite
of metals in the Middle–Late Bournonite
Jurassic continental crust and Bismuthinite
Bertierite
Meliatic mantle mobilization, Garavellite40
39
as indicated by Ar– Ar data Chalcostibnite
from the Meliatic Unit (150– Stibnite
170 Ma; Maluski et al. 1993; Ullmanite

189

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

Strieborná vein

NW

SE

2

1

0 [m]

2

SW

6

4
NE

SW

8

NE

2

2

12

E

ar

2

10

W

l

na

nts

joi

e
sh

go

dia

0 [m]

2

0 [m]

0 [m]

2

metaquarzites

cross-sections localization

metasandstones and metapelites

a

NW

2

SE

sideritetetrahedrite
quartzmineralization distribution
in boudin bodyFig. 12 Spatial view of a boudin at the 6th mining level. Boudinage created irregular tetrahedrite bodies and was tectonically restricted by fault
subparallel to Transgemeric shear zone. The spatial position of tensile diagonal shear joints and tetrahedrite accumulation relates to minimum
stress direction.

(Fig. 11). Similar relationships show tetrahedrite inherence at siderite brecciated fragments, replaced by bulky
nests of massive tetrahedrite (Mikuš et al. 2018, Fig. 3).
Moreover, tetrahedrite/siderite contacts are etched byberthierite, garavellite and stibnite veinlets (Fig. 5). This
younger sulphosalts association shows an opposite vertical
zonation on mine-scale (i.e. decrease in Sb and an increase
in Bi contents with increasing depth). In this context weare able to track volumes of argentiferous tetrahedrite.
Tetrahedrite contents up to 0.71 wt. % Ag are restricted
to deeper mining levels and deeply located, bulkier symmetric boudins (Fig. 13). In vertically shifted asymmetricboudin, emplaced in the soft surrounding environment of
the upper, i.e. the 6th mine horizon, Ag content increases
even to 0.74–1.71 wt. %. The Strieborna vein vertical ore
distribution likely reflects more factors than other deposits in the Rožňava ore field, e.g. different mineralization

190

sources, vertical precipitation differences at both periodsof the second, i.e. quartz–sulphidic mineralization phase,
distinct rheological contrasts of the parent rocks environment, and mineralization content/volume changes due tovein boudinage deformation events (Figs 4, 6, 9, 12–13).
As an initial source for Gemeric Unit quartz–sulphidic
phase formation, Hurai et al. (2008) determined an immiscible gas–brine mixture enriched by basement rocks
percolation at c.140–300° C. For sulphide veins of theSouth Gemeric zone, they assumed up to 16 km burial
depth and onto 0.6 kbar decreased fluid pressure during
crystallization. Formation of the sulphidic assemblage
in the Rožňava area possibly related to younger, Late
Cretaceous transpressional TGSZ events, as would certify
an appropriate K–Ar diapason (68–97 Ma) from Čučma
quartz–stibnite vein and stilpnomelane from the Rožnava
siderite deposit (Kantor 1957; Bagdasaryan et al. 1977).

Boudinage of hydrothermal veins in the shear zone

Hydrothermal minerals constituting the Strieborna veinprecipitated during the entire (long-lasting) deformation
evolution (Fig. 14), comprising three deformation stages
in detail (Fig. 11). The presence of an older boudinage
event, pre-dating the quartz–sulphidic mineralization
phase, has not been verified in the ROF area till now.
This suggests onset of the Strieborna vein early boudinage somewhere at the beginning of the quartz–sulphidic
mineralization phase. On the other hand, the youngest
minerals of the Strieborna vein mineralization (i.e. endof the second period of the second mineralization phase)lack evidence of deformation but create veinlets and (or)myrmekitic intergrowths at tetrahedrite–siderite contacts(Mikuš et al. 2018 and Fig. 9). Hence it is reasonable toassume a Late Cretaceous post-deformation closure of theStrieborna vein hydrothermal mineralization.

350

assymmetricand bended boudin

Ag,Sb
Bi

chemical components Increasing

5.4. Boudinage of the Strieborna vein
mininglevel 6(+180m a.s.l.)rupture
zone

neck
?

metaquarzites
metasandstones
and metapelites
sideritemininglevel 10(–20 m b.s.l.)tetrahedrite

symmetric
and linear boudin

130 mining
level 13(–170 m b.s.l.)

0 [m]

4

8

Fig. 13 Vertical scheme illustrates creation of boudins of symmetricand asymmetric morphology due to different host-rocks rheology. Distribution of chemical compositions relates to successive mineralization
process of tetrahedrite and sulphosalts as well as boudin formation.

6. Conclusions
The origin of argentiferous Strieborna vein of theRožňava ore field located at the southwestern margin of
the Early Paleozoic basement of the Gemeric belt closely
relates to the Early Cretaceous tectonometamorphic evo-

BOUDIN
pre-deformation

initialpre-Alpine

boudin forming

boudins differentiation

Late Jurassic–Early Cretaceousvein deformation

Late Cretaceous

shorteningafilled vein body

STAG E Sbvertical stretching

c

d

e

f
NE
SW

stratiform
siderite

metasomaticquartzsiderite

HDT siderite
quartzsiderite(Bi) sulphosalts(Ag) tetrahedrite
HDT siderite
quartzsiderite(Ag) tetrahedrite(Bi) sulphosalts(Ag) tetrahedrite
HDT siderite
quartzsiderite(Sb) sulphosalts(Ag) tetrahedrite(Bi) sulphosalts(Ag) tetrahedrite
HDT siderite
quartzsideritehydrothermal mineralization

Fig. 14 Six evolutionary stages of the Strieborna vein formation reflecting interplay between mineralization and deformation processes. Mineralization phases (red colour – active) precipitated and deformed gradually either throughout the TGSZ sequential shortening or vertical stretching (Sasvári
and Maťo 1998; Mikuš et al. 2018). The vein boudinage deformations run across three successive stages. The initial stage closed precipitation of
the quartz–sulphidic phase, the medial one was related to the shear deformation prior to precipitation of the first sulphosalt association. The third
boudinal stage was characterized by vertical stretching of rock successions, creation of stylolites and boudins transversal necking (see Fig. 9).
With depth decreasing Ag, Sb, and increasing Bi contents for sulphosalts are characteristic. The older sulphosalt association tintinaite–kobellite–
Bi-jamesonite–bournonite represents the older phase with the higher Bi content. In contrast, a low Bi content in tetrahedrite is a typical feature of
the Gemeric belt (e.g. Pršek and Biroň 2007; Števko et al. 2015). We would like to remind that both sulphosalts associations, together with Sbstibnite (see Fig. 11), as well as Čučma Sb-stibnite deposit (Beňka and Caňo 1992), terminated the veins hydrothermal mineralization in the area.

191

Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

lution of the Western Carpathians. The main results on
the studied Strieborna vein formation can be summarized
as follows:
1. The subduction of the oceanic crust in the Meliata
oceanic trough at 152–172 Ma released Mg, Fe andsimilar elements for their syntectonic Early Cretaceous
precipitation at penetratingly prepared ore-bearing
structures of the Paleozoic Gemeric belt.
2. The Strieborna vein is best developed in rheologicallycompetent metavolcanic and metapsammitic rocks. In
the less competent phyllitic media, the vein strike andthickness change, often being reduced substantially.
For an initial emplacement, the vein body utilized fan-like cleavage and faults set of the Early Cretaceous
regional fold axial structure, as confirm 40Ar–39Ar ages,
regional metamorphic and structural data.
3. Strieborna vein deformations were markedly related tothe sinistral brittle–ductile shearing along the Transgemeric shear zone (TGSZ). Five boudin bodies, several
tens to more than 100 m in length, are observed between 6th and 10th mining levels of the vein. They werecreated at two regional dislocation sets of NNE–SSW
and NE–SW directions. Both of them spatially corresponded with the principal Alpine structures of theRožňava mining area and show slightly to moderately
inclined strike-slip kinematics.
4. Boudins of specimen dimensions provide valuable
information about the successive evolution of shear
zone deformation, kinematics, and internal geometry
as well as the precipitation of individual vein associations.
5. The oldest demonstrable Strieborna vein boudinage
stage was the post-quartz–siderite one which fixedvein consecutive deformations. The presence ofsiderite grains rotated to the direction of stretching
lineation and diagonally oriented stylolitic seams
certify fol­lowing successive deformations of the veinbody and implicitly also the final kinematic patternof the TGSZ.
6. Close deformation and temporal analogies are shownby the youngest sulphosalts association of the Strieborna vein and Sb-stibnite–sulphosalts of the same phasein the nearby Čučma ore vein deposit. These analogies
indicate a similar genesis of terminal associations inthese two vein deposits.
7. Proximal tectonometamorphic evolution of the Alpine
Gemeric and South Veporic units indicates the syntectonic hydrothermal mineralization of the Rožňava
ore field and also transpressional deformations of the
TGSZ in Early Cretaceous (75–85 Ma ago).
Acknowledgements. We acknowledge the constructive comments and excellent editorial handling ofJ. Zachariáš.
192

References
Andrusov D (1968) Grundriss der Tektonik der Nördlichen
Karpaten. Slovak Academy of Sciences, Bratislava, pp
1–188
Bajaník Š, Hanzel V, Ivanička J, Mello J, Pristaš J,
Reichwalder P, Snopko L, Vozár J, Vozárová A(1983) Explanations to geological map of the Slovenské
Rudohorie Mts. – eastern part. Dionýz Štúr Geological
Institute, Bratislava, pp 1–223 (in Slovak)
Bagdasaryan GP, Cambel B, Veselský J, Gukasajan
RCh (1977) K–Ar age determinations of the rocks fromcrystalline complexes of the Western Carpathians andpreliminary interpretation of results. Geol Zbor Geol
Carpath 28: 365–374
Baker DEL, Seccombe PK, Collins WJ (2002) Structural
history and timing of gold mineralization in the northern
East Strelley Belt, Pilbara Craton, Western Australia.
Econ Geol 97: 775–785Beňka J, Caňo F (1992) Mineralogy, paragenesis and geochemistry of antimony veins from the Betliar–Čučma–
Volovec area. Západ Karpaty, Ser Mineral Petrogr
Geochem Metalogen 15: 61–91
Bezák V, Biely A, Broska I, Bóna J, Buček S, Elečko
M, Filo I, Fordinal K, Gazdačko Ľ, Grecula
P, Hraško Ľ, Ivanička J, Jacko S sen., Jacko S
jun., Janočko J, Kaličiak M, Kobulský J, Kohút
M, Konečný V, Kováčik M, Lexa J, Madaras J,
Maglay J, Mello J, Nagy Z, Németh Z, Olšavský M,
Plašienka D, Polák M, Potfaj M, Pristaš J, SimanP, Šimon L, Teták F, Vozárová A, Vozár J, Žec B(2009) Explanations to the general geological map ofSlovak Republic, scale 1 : 500 000. Geological Surveyof the Slovak Republic, Bratislava, pp 1–534 (in Slovak
with English summary)
Dabrowski M, Grasemann B (2014) Domino boudinage
under layer-parallel simple shear. J Struct Geol 68: 58–65
Dallmeyer RD, Neubauer F, Fritz H, Mocanu V (1994)
Pre-Variscan, Variscan and Alpine tectonothermal evolution within the southern Carpathians, Romania: evidence
from 40Ar–39Ar hornblende and muscovite ages. J Czech
Geol Soc 39: 18–19
Dallmeyer RD, Neubauer F, Handler R, Fritz H, Müller W, Pana D, Putiš M (1996) Tectonothermal evolution of the internal Alps and Carpathians: evidence from40
Ar–39Ar mineral and whole-rock data. Eclogae Geol
Helv 89: 203–227
Dallmeyer RD, Neubauer F, Fritz H (2008) The Meliata suture in the Carpathians: regional significance andimplications for the evolution of high-pressure wedges
within collisional orogens. In: Siegesmund S, Fügenschuh B, Froitzheim N (eds) Tectonic Aspects of the
Alpine–Dinaride–Carpathian System. Geological Societyof London, Special Publications 298: 101–115

Boudinage of hydrothermal veins in the shear zone

Faryad SW (1991) Metamorphism of the Early Paleozoic sedimentary rocks in the Gemericum. Miner Slov 23: 315–324
Faryad SW (1995) Determination of P–T metamorphism
conditions in the Early Paleozoic Gemericum rock sequences. Miner Slov 27: 9–19
Faryad SW, Henjes-Kunst F (1997) Petrological and K/
Ar and 40Ar/39Ar age constraints for the tectonothermal
evolution of the high-pressure Meliata Unit, Western
Carpathians (Slovakia). Tectonophysics 280: 141–156
Finger F, Broska I (1999) The Gemeric S-type granites insoutheastern Slovakia: Late Palaeozoic or Alpine intrusion? Evidence from the electron-microprobe dating ofmonazite. Schweiz mineral petrogr Mitt 79: 439–443
Ghosh SK, Sengupta S (1999) Boudinage and composite
boudinage in superposed deformations and syntectonic
migmatization. J Struct Geol 21: 97–110
Goscombe B, Passchier CW (2003) Asymmetric boudins
as shear sense indicators – an assessment from field data.
J Struct Geol 25: 575–589
Goscombe B, Passchier CW, Hand M (2004) Boudinage
classification: end-member boudin types and modified
boudin structures. J Struct Geol 26: 739–763
Grecula P, Návesňák D, Bartalský B, Gazdačko Ľ,
Németh Z, Ištván Z, Vrbatovič P (1990) Shear zones
and arc structure of Gemericum, the Western Carpathians.
Miner Slov 22: 97–110
Grecula P, Abonyi A, Abonyiová M, Antaš J, Bartalský
B, Bartalský J, Dianiška I, Drnzík E, Ďuďa R, Gargulák M, Gazdačko Ľ, Hudáček J, Kobulský J, Lörincz
L, Macko J, Návesňák D, Németh Z, Novotný L,
Radvanec M, Rojkovič I, Rozložník L, Rozložník O,
Varček C, Zlocha J (1995) Raw deposits of the Slovak
ore Mountains. Geocomplex, Bratislava, pp 1–834
Grecula P, Kobulský J, Bajtoš P, Gazdačko Ľ, Hraško
Ľ, Kucharič Ľ, Maglay J, Németh Z, Novotný L,
Pramuka S, Radvanec M, Záhorová Ľ (2011) Explanation to geological map of the Spišsko–Gemerské
rudohorie Mts., scale 1:50 000. Dionýz Štúr Geological
Institute, Bratislava, pp 1–308 (in Slovak with English
summary)
Hanmer, S, Passchier C (1991) Shear-Sense Indicators:
A Review. Geological Survey of Canada Papers 90-17,
pp 1–72
Hurai V, Harčarová E, Huraiová M, Ozdín D, Prochaska W, Wiegerová V (2002) Origin of siderite veinsin the Western Carpathians I. P–T–X–δ13C–δ18O relations
in ore-forming brines of the Rudňany deposits. Ore Geol
Rev 21: 67–101
Hurai V, Lexa O, Schulmann K, Montigny R, Prochaska W, Frank W, Konečný P, Kráľ J, Thomas
R, Chovan M (2008) Mobilization of ore fluids during
Alpine metamorphism: evidence from hydrothermalveins in the Variscan basement of Western Carpathians,
Slovakia. Geofluids 8: 181–207

Jacko S (1979) Geological cross-section through Čierna
hora belt. In: Maheľ M (ed) Tectonic Cross-section of theWestern Carpathians. Dionýz Štúr Geological Institute,
Bratislava, pp 185–193
Jacko S, Sasvári T (1990) Some remarks to an emplacement mechanism of the West Carpathian Paleo-Alpine
nappes. Geol Carpath 41: 179–197
Kantor J (1957) 40Ar/40K method for determining the absolute age and the age of the Gemeric Betliar granites.
Geol Práce, Zpr 11: 188–200
Lexa J, Bačo P, Hurai V, Chovan M, Koděra P, Petro
M, Rojkovič I, Tréger M (2007) Explanatory notes tothe metallogenetic map of Slovak Republic 1 : 500 000.
Dionýz Štúr Geological Institute, Bratislava, pp 1–178
Lexa O, Schulmann K, Ježek J (2003) Cretaceous collisionand indentation in the West Carpathians: view based on
structural analysis and numerical modeling. Tectonics
22: 1066, DOI: 10.1029/2002TC001472
Lloyd GE, Ferguson CC (1981) Boudinage structure –some new interpretations based on elastic–plastic finiteelement simulations. J Struct Geol 3: 117–128
Maheľ M (1986) Geological Structure of the Czechoslovak
Carpathians. Paleoalpine Units. Veda, Bratislava, pp
1–503 (in Slovak with English summary)Maluski H, Rajlich P, Matte P (1993) 40Ar–39Ar datingof the Inner Carpathian Variscan basement and Alpine
mylonitic overprinting. Tectonophysics 223: 313–337
Martins BD, Lobato LM, Rosiere CA, Hagemann SG,
Santos JOS, Villanova FLDP, Silva RCFE, Lemos
LHD (2016) The Archean BIF-hosted Lamego gold
deposit, Rio das Velhas greenstone belt, Quadrilatero
Ferrifero: evidence for Cambrian structural modification of an Archean orogenic gold deposit. Ore Geol Rev
72: 963–988
Mesarčík I (1994) Preliminary Report With Operational
Reserves Calculation of the Rožňava – Silver Vein II.
Unpublished manuscript, Geoenvex, s.r.o., Rožňava, pp
1–53 (in Slovak)
Mesarčík I, Jeleň M, Bachňák M, Švantnerová E, Zatroch P, Leška S, Hajči T, Palčo A, Tuček L, Košuth
M, Ujpál Z, Marko F, Stupák J (1991) Final Report
With Reserves Calculation of the Rožňava – Silver Vein.
Unpublished manuscript, Geologický prieskum, š.p.,
Spišská Nová Ves, Geologická oblasť Rožňava, pp 1–95
Mikuš T, Kondela J, Jacko S, Milovska S (2018) Garavellite and associated sulphosalts from the Strieborna veinin the Rožňava ore field (Western Carpathians). Geol
Carpath 69: 221–236
Németh Z (2002) Variscan suture zone in the Gemericum:
contribution to reconstruction of geodynamic evolution
and metallogenetic events of Inner Western Carpathians.
Slovak Geol Mag 8: 247–257
Németh Z, Gazdačko L, Návesňák D, Kobulský J (1997)
Polyphase tectonic evolution of the Gemericum (the193Stanislav Jacko, Roman Farkašovský, Julián Kondela, Tomáš Mikuš, Barbora Ščerbáková, Diana Dirnerová

Western Carpathians) outlined by review of structural anddeformational data. In: Grecula P, Hovorka D, Putiš M(eds) Geological Evolution of the Western Carpathians.
Geocomplex, Bratislava, pp 215–224
Németh Z, Putiš M, Hraško Ľ (2016) The relation of metallogeny to geodynamic processes – the natural prerequisite for origin of mineral deposits of public importance(MDoPI): the case study in the Western Carpathians,
Slovakia. Miner Slov 48: 119–134
Passchier CW, Druguet E (2002) Numerical modellingof asymmetric boudinage. J Struct Geol 24: 1789-1803
Passchier CW, Trouw RAJ (2005) Microtectonics.
Springer, Berlin, pp 1–366
Plašienka D (1999) Tectochronology and Paleotectonic
Model of Jurassic and Cretaceous Evolution in the Central Western Carpathians. Veda, Bratislava, pp 1–125
Plašienka D, Havrila M, Michalík J, Putiš M, Reháková
D (1997) Nappe structure of the western part of theCentral Carpathians. In: Plašienka D, Hók J, Vozár J,
Elečko M (eds) Alpine Evolution of the Western Carpathians and Related Areas. International Conference,
Abstracts and Introductory Articles to the excursion.
Geological Survey of Slovak Republic, Dionýz ŠtúrPublisher, Bratislava, pp 139–161
Plašienka D, Grecula P, Putiš M, Kováč M, Hovorka D(1999) Evolution and structure of the Western Carpathians: an overview. In: Grecula P, Hovorka D, Putiš M(eds) Geological Evolution of the Western Carpathians.
Geocomplex, Bratislava, pp 1–24
Poller U, Uher P, Broska I, Janák M, Plašienka D(2002) First Permian–Early Triassic zircon ages fortin-bearing granites from Gemeric Unit (Western Carpathians, Slovakia): connection to the post-collisional
extension of the Variscan orogen and S-type magmatism.
Terra Nova 14: 41–48
Pršek J, Biroň A (2007) Jaskólskiite and associated sulphosalts from Aurélia vein, Spišsko–gemerské rudohorie
Mts. Miner Slov 39: 141–146
Putiš M, Ivan P, Kohút M, Spišiak J, Siman P, Radvanec
M, Uher P, Sergeev S, Larionov A, Méres S, DemkoR, Ondrejka M (2009) Meta-igneous rocks of theWest-Carpathian basement, Slovakia: indicators of Early
Paleozoic extension and shortening events. Bull Soc geol
France 180: 461–471
Rajabzadeh MA, Rasti S (2017) Investigation on mineralogy, geochemistry and fluid inclusions of the Goushti
hydrothermal magnetite deposit, Fars Province, SW
Iran: a comparison with IOCGs. Ore Geol Rev 82:
93–107
Ramsay JG, Huber MI (1987) The Techniques of Modern
Structural Geology. Volume 2: Folds and Fractures.
Academic Press, London, pp 516–633
Reichwalder P (1982) Structural characteristics of rootzone of some nappes in innermost parts of West Car194

pathians. In: Maheľ M (ed) Alpine Structural Elements.
Carpathian–Balkan–Caucasus–Pamir Orogene Zone.
Veda, Bratislava, pp 43–56
Roache TJ (2004) Shear zone versus fold geometries at
the Cannington Ag–Pb–Zn deposit: implications for thegenesis of BHT deposits. J Struct Geol 26: 1215–1230
Rodrigues B, Pamplona J (2018) Boudinage and shearband boudins: a meso- to micro-scale tool in structural
analysis. J Struct Geol 114: 280–287
Rodrigues BC, Peternell M, Moura A, Schwindinger
M, Pamplona J (2016) P–T path development derived
from shearband boudin microstructure. J Struct Geol
90: 95–110
Rozložník L (1976) Relationship of Siderite Metalogenesis and Tectonics of the Spis Ore Mountains and Their
Position in Alpides. Faculty BERG, Košice, pp 1–301
Rozložník L (1980) Classification of the mineralized
structures in the Spišsko–gemerské Rudohorie Mts. Geol
Carpath 31: 421–439
Rozložník L (1984) Source and structural conditions ofsiderite deposits formation in the Spišsko–gemerské
Rudohorie Mts. (West Carpathians). Proceedings of
the Sixth IAGOD Symposium. Schweizerbart’sche E.
Verlagsbuchhandlung, Stuttgart, pp 187–189
Rozložník L (1990) Gemericum shear zone – bearer ofsiderite formation. Miner Slov 22: 47–54
Samanta SK, Majumder DB, Sarkar G (2017) Geometryof torn boudin – an indicator of relative viscosity. J Struct
Geol 104: 21–30
Sasvári T, Maťo Ľ (1998) The characteristics of theRožňava ore district, in relation to the structural–tectonic
analysis and mineralization exampled by the deposition
conditions of the Strieborna vein, Mária mine, Rožňava.
Acta Mont Slov 3: 33–117
Schulmann K, Kröner A, Hegner E, Wendt I, Konopásek J, Lexa O, Štípská P (2005) Chronologicalconstraints on the pre-orogenic history, burial and exhumation of deep-seated rocks along the eastern margin of
the Variscan Orogen, Bohemian Massif, Czech Republic.
Amer J Sci 305: 407–448
Smith MT, Rhys D, Ross K, Lee C, Gray JN (2013)
The long canyon deposit: anatomy of a new off-trend
sedimentary rock-hosted gold discovery in northeastern
Nevada. Econ Geol 108: 1119–1145Števko M, Sejkora J, Peterec D (2015) Grumiplucitefrom the Rudňany deposit, Slovakia: a second worldoccurrence and new data. J Geosci 60: 269–281
Varček C (1963) Hydrotherm mineralization zonality of
the Spiš–Gemer Ore Mountains and geological structure impact to mineralization pattern. In: X Congress of
Carpathian–Balkan Geological Association, Bucharest
1961, Guide to Excursion, pp 277–292
Varček C (1973) Paragenetic and geochemical patterns ofhydrothermal deposits in the Spiš–Gemer Ore Moun-

Boudinage of hydrothermal veins in the shear zone

tains. In: Bartalský J (ed) Geological Ore Study of theSpiš–Gemer Ore Mountains. Komenského University
Publisher, Bratislava, pp 1–122 (in Slovak)
Vozárová A (1993) Variscan metamorphism and crustal
evolution of the Gemericum. Západ Karpaty Sér Mineral
Petrogr Geochem Metalogen 16: 55–117 (in Slovak withEnglish summary)Vozárová A, Ivanička J (1996) Geodynamic position ofacid volcanism of the Gelnica Group (Early Paleozoic,
southern Gemericum; Inner Western Carpathians). Slovak Geol Mag 3–4: 245–250
Vozárová A, Rodionov N, Vozár J, Lepekhina E,Šarinová K (2016) U–Pb zircon ages from Permian
volcanic rocks and tonalite of the Northern Veporicum(Western Carpathians). J Geosci 63: 221–237

195