METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 267
GEOLOGICA CARPATHICA, 54, 5, BRATISLAVA, OCTOBER 2003
267280
GEOCHEMICAL DISCRIMINATION OF METASEDIMENTARY
SEQUENCES IN THE KRKONOE-JIZERA TERRANE
(WEST SUDETES, BOHEMIAN MASSIF):
PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS
JOHN A. WINCHESTER
1
, FRANTIEK PATOÈKA
2
, VÁCLAV KACHLÍK
3
, MATTYLD MELZER
1
,
CLAIRE NAWAKOWSKI
1
, QUENTIN G. CROWLEY
1
and PETER A. FLOYD
1
1
School of Earth Sciences and Geography, Keele University, Staffs ST5 5BG, U.K.
2
Institute of Geology, Academy of Sciences of the Czech Republic, Rozvojová 135, 165 02 Prague 6, Czech Republic; patocka@gli.cas.cz
3
Institute of Geology and Palaeontology, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic
(Manuscript received July 8, 2002; accepted in revised form March 11, 2003)
Abstract: Metamorphosed clastic sediments from three lithostratigraphic groups (the low- to medium-grade Velká Úpa,
and the low-grade Radèice and Poniklá Groups), exposed in a para-autochthonous to allochthonous unit of the Krkonoe-
Jizera Terrane (KJT, West Sudetes), were studied in order to discover whether they are chemically discriminable. Ac-
cording to chemical features of the metasediments (e.g. lower Th/Sc and Ce
N
/Yb
N
ratios), the Velká Úpa Group is
interpreted to be younger than the Neoproterozoic Machnín Group (of the KJT autochthonous unit) related to a Cadomian
active continental margin setting. Metamorphosed clastics of the Poniklá and Radèice Groups proved to be chemically
indistinguishable. As a result, these groups are herein combined within a single Vrchlabí Group of Cambrian-Ordovician
to Silurian (±Devonian?) age. Precursors of the Velká Úpa and Vrchlabí Groups were apparently deposited on a passive
margin of the peri-Gondwanan Saxothuringian microplate. The passive margin originated in Cambrian and Ordovician
times during extension and rifting of the former (Cadomian) active continental margin of NW Gondwana. Comparison of
the metasediment geochemistry, together with the stratigraphic and structural affinities within the KJT, allows the Velká
Úpa and Vrchlabí Groups to be interpreted as broadly coeval: Cambrian to Silurian (±Devonian?) in age. Deposition of
the Vrchlabí Group was more distal and sourced by sediment derived from a more dissected area of the Cadomian
basement (fossil active margin) as demonstrated by an enrichment in Hf, depletion in Sc and Cr, somewhat higher Ce
N
/Yb
N
values and slightly more pronounced negative anomalies of Eu. The geochemistry of the metasediments reflects the
complex paleotectonic evolution of the West Sudetes that started with Cambrian-Ordovician intracontinental rifting and
subsequent sea-floor spreading during marginal fragmentation of Gondwana.
Key words: Bohemian Massif, West Sudetes, Early Paleozoic, paleotectonic setting, geochemistry of clastic
metasediments.
Introduction
The West Sudetes comprise Neoproterozoic to Early Carbon-
iferous low- to medium-grade metamorphosed sedimentary
and volcano-sedimentary sequences successively intruded by
latest Neoproterozoic, Early and Late Paleozoic granitoid bod-
ies (Svoboda & Chaloupský 1966; Teisseyre 1973; ¯ela-
niewicz 1997). The West Sudetes are also a collage of distinct
tectonostratigraphic units which have been interpreted as ter-
ranes, identifiable by their distinct stratigraphic, igneous and
tectonometamorphic records (Matte et al. 1990; Narêbski
1994; Cymerman et al. 1997; Aleksandrowski et al. 2000;
Franke & ¯elaniewicz 2000).
These West Sudetic terranes specifically display: (a) pro-
tracted Early Paleozoic rift-related bimodal volcanism and ini-
tial Cambro-Ordovician granitoid magmatism (Furnes et al.
1994; Kryza et al. 1995; Kryza & Pin 1997; Bia³ek 1998;
Kachlík & Patoèka 1998a; Floyd et al. 2000; Dostal et al.
2001); (b) Late Devonian/Early Carboniferous subduction and
HP-LT metamorphism followed by rapid uplift of deeply-bur-
ied crustal slices, and exhumation-related equilibration of the
HP-LT rocks in greenschist-facies conditions (Cháb & Vrána
1979; Mazur & Kryza 1996; Patoèka et al. 1996; Maluski &
Patoèka 1997; Smulikowski 1999), and (c) an E to W oriented
delay in the onset of flysch sedimentation recently dated as
Late Devonian to Early Carboniferous (Hladil et al. 1998; Ma-
zur & Kryza 1999; Kachlík & Patoèka 2001).
The juxtaposition of the West Sudetic terrane mosaic is in-
terpreted as a result of (early?) Variscan (e.g. Marheine et al.
2002) collision of the Gondwana-derived Armorican Terrane
Assemblage with Laurussia (cf. Franke 1998; Pharaoh 1999),
and late Variscan dextral displacements along prominent
strike-slip faults parallel to the Trans-European Suture Zone
(TESZ, e.g. Aleksandrowski et al. 1997, 2000). From its com-
mon characteristics, the West Sudetic Terrane Assemblage
may be regarded as an eastern continuation of the Saxothurin-
gian domain (microplate), situated adjacent to the former SW
margin of Laurussia (see Franke et al. 1993; Crowley et al.
2002; Winchester et al. 2002).
Geological setting
The Krkonoe-Jizera Terrane (KJT), situated in the West
Sudetes of the northern Bohemian Massif, is currently inter-
preted as a Variscan NW-directed orogenic wedge, which de-
268 WINCHESTER et al.
veloped between the orogenic root of the Orlica-Snienik
lower to middle crustal complexes in the E, and autochtho-
nous (Cadomian) Lusatian foreland to the NW. In the KJT the
following tectonostratigraphic units have been distinguished
(e.g. Kachlík & Patoèka 1998a, 2001; Kachlík & Kozdroj
2001) (Figs. 1 and 2):
(1) Autochthon. Exposed along the NW margin of the
Jetìd Range Unit (the westernmost part of the KJT at the
boundary with the Lusatian Terrane), the autochthon is the
foreland of the overlying tectonostratigraphic units. It com-
prises a Neoproterozoic basement of Lusatian granitoids (dat-
ed at 540587 Ma, Kröner et al. 1994a) and their associated
host rocks, the Machnín Group metagreywackes (Chaloupský
et al. 1989) dated at 562±4 Ma (Gehmlich et al. 1997). Fol-
lowing the end-Proterozoic Cadomian Orogeny, the Neoprot-
Fig. 1. Simplified geological map of the Krkonoe-Jizera Terrane. The inset shows the studied region both within the Bohemian Massif and
within the European Variscan Belt. S-TZ Sorgenfrei-Tornquist Zone, T-TZ Teisseyre-Tornquist Zone, ML Moravian Line (cf.
Pharaoh 1999; Winchester et al. 2002). Key: 1 Neoproterozoic Machnín Group (metagreywackes metapelites); 2 Cadomian Zawidow
Granodiorite; 3 Cambrian Rumburk-type Granite; 4 mica schists to paragneisses within the Izera orthogneiss; 5 Cambro-Ordovi-
cian(?) Izera and Krkonoe (Kowary) orthogneiss; 6 phyllites with intercalations of Middle to Late Devonian marbles (v); 7 very low-
grade metamorphosed Late Devonian to Early Carboniferous flysch deposits with intercalations of mafic-felsic metavolcanics (B) and mar-
bles (v); 8 Early Paleozoic sericite-chlorite phyllites (roofing slates) and basic metatuffites with metadiabase sills and dykes (B), rare
metagabbros, picrites; 9 Cambro-Ordovician elezný Brod and Rýchory Metavolcanic Complexes (metabasaltic pillow lavas, metatuffs
and acid metavolcanics); 10 Early Paleozoic sericite phyllites with abundant intercalations of marbles (v) and quartzites (q) and basic
metavolcanics (B); 11 minor bodies of phyllonitized granites and orthogneisses (G); 12 Krkonoe-Jizera late-Variscan Granite Pluton;
13 Permo-Carboniferous deposits of the Krkonoe Piedmont Basin; 14 deposits of the Czech Cretaceous Basin; 15 Pliocene basan-
ites and olivine basalts; 16 sample sites (only samples with complete sets of major and trace element data are shown here see Tables 1
and 2). ABC line of a schematic geological cross-section (see Fig. 2).
erozoic basement was intruded by granites dated at ca. 515
480 Ma (Borkowska et al. 1980; Oliver et al. 1993; Kröner et
al. 1994b). The basement is unconformably overlain by Paleo-
zoic rocks folded and metamorphosed during the Variscan
Orogeny (Kachlík & Patoèka 2001; Kachlík et al. 2002).
(2) Para-autochthonous to allochthonous composite unit.
Most of this unit is exposed in a large antiform in the KJT, and
it is also preserved in minor tectonic slices in the central part of
the Jetìd Range Unit. The KJT antiform consists of the Izera
and Krkonoe (Kowary) gneiss body (e.g. Svoboda & Cha-
loupský 1966; ¯elaniewicz 1997) mantled on the E and S by
volcano-sedimentary sequences of the East and South
Krkonoe Complexes (cf. Teisseyre 1973; Mazur & Kryza
1996; Kachlík & Patoèka 1998a,b; Patoèka et al. 2000; Dostal
et al. 2001) enclosing tectonic slices of related porphyritic
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 269
Fig. 2. Schematic geological cross-section of the Krkonoe-Jizera Terrane. 1 Neoproterozoic Machnín Group (metagreywackes >>
metapelites); 2 Cadomian Zawidow Granodiorite; 3 Cambro-Ordovician(?) Izera and Krkonoe (Kowary) orthogneiss; 4 Lower Pa-
leozoic sericite-chlorite phyllites (roofing slates) and basic metatuffites with metadiabase sills and dykes (B), rare metagabbros, picrites;
5 Cambro-Ordovician elezný Brod and Rýchory Metavolcanic Complexes (metabasaltic pillow lavas, metatuffs and acid metavolca-
nics); 6 Lower Paleozoic sericite phyllites with abundant intercalations of marbles (v) and quartzites (q) and basic metavolcanics (B); 7
phyllites with intercalations of Middle to Upper Devonian marbles (v); 8 very low-grade metamorphosed Upper Devonian to Lower Car-
boniferous flysch deposits with intercalations of mafic-felsic metavolcanics (B) and marbles (v); 9 Krkonoe-Jizera late-Variscan Granite
Pluton; 10 faults; 11 thrust faults. For references of the A, B and C points see Fig. 1.
was paleontologically dated (e.g. Horný 1964; Chlupáè
1993). Minor granitoid gneiss bodies occur in all the above
mentioned lithostratigraphic groups (Kachlík et al. 1999,
2002).
The KJT metasedimentary groups comprise rather similar
metapelite-dominated lithologies and include many extensive
mylonitic zones, suggesting that repetition of stratigraphic
successions by ductile thrusting has occurred. However, this
is difficult to prove as, because of the deformation and meta-
morphism of these rocks, preserved fossils are scarce. They
are also difficult to distinguish on lithological grounds, since
progressive metamorphism and metamorphic growth of albite
has obscured original structures and textures in the metasedi-
ments (particularly in the East Krkonoe Complex). The accu-
racy of the distinction made on published maps (e.g. Cha-
loupský et al. 1968; Chaloupský 1989) is therefore
questionable.
Aim of this work
No chemical study has previously been made of these
metasedimentary rocks. Hence, the aim of this study was to
analyse the metasedimentary rocks from all these groups in
order to discover whether they are chemically distinguishable
and, if so, to test the validity of the current geological/strati-
graphic interpretations made on the map (e.g. Chaloupský
1989). Further aims include eliciting information about the
nature of the original sediment and its source rocks as well as
the paleotectonic scenarios of the KJT previously indicated by
the geochemistry of the meta-igneous rocks.
Sampling
Thirty samples were collected of variably mylonitized non-
calcareous metasedimentary rocks (Tables 1 and 2) currently
mapped as belonging to the Velká Úpa, Radèice and Poniklá
Groups (Chaloupský 1989). Lithotypes ranged from pale
quartzite (7 samples), through micaceous metapsammites
(5 samples) to (most abundantly) dark grey or greenish phyl-
litic, mostly pelitic schists (18 samples). In addition, three ul-
tramylonitic samples (not included in the tables) contained
metagranites (Kachlík et al. 1999). The KJT (meta)granites
and gneisses are mostly considered to be CambrianOrdovi-
cian in age (e.g. Borkowska et al. 1980; Oliver et al. 1993;
Kröner et al. 1994b; Kachlík et al. 1999, 2002).
The East and South Krkonoe Complexes show consider-
able diversity both in lithology and metamorphic grade
(Kachlík & Patoèka 1998a). The stratigraphic range of the
complexes is interpreted as Cambrian to Devonian, according
to scarce radiometric dates (e.g. Oliver et al. 1993; Bendl &
Patoèka 1995; Timmermann et al. 1999; Marheine et al. 2000,
2002) and fossil finds (e.g. Horný 1964; Chlupáè 1993, 1997,
1998; Konzalová & Hrabal 1998; Hladil et al. 1998; Hoth
2000; Walter 2000; Hladil et al. 2003). In contrast to the KJT
autochthon, the East and South Krkonoe Complexes experi-
enced early Variscan blueschist metamorphism (at ca. 360
Ma) (Maluski & Patoèka 1997) accompanied by a NW-SE-di-
rected linear fabric of the KJT (Mazur & Kryza 1996; Seston
et al. 2000), followed by a widespread greenschist facies over-
print between 340345 Ma (Marheine et al. 2000). Major late
Variscan shearing and thrusting resulting in metamorphic zon-
al inversion between 340 and 320 Ma (Kachlík & Patoèka
1998a; Marheine et al. 2002) was followed by intrusion of the
post-tectonic Krkonoe-Jizera pluton, emplaced into the core
of the KJT antiform, and dated at 328 and 313 Ma, respective-
ly (Pin et al. 1987; Marheine et al. 2002).
Metamorphosed sedimentary and volcano-sedimentary se-
quences of the para-autochthonous to allochthonous unit of
the KJT (as defined above) were studied earlier by Cha-
loupský et al. (1968, 1989), who distinguished three litho-
stratigraphically characterized groups: (a) low- to medium-
grade Middle Proterozoic metasedimentary Velká Úpa Group,
associated with and probably intruded by the Izera and
Krkonoe (Kowary) granitoid gneisses exposed in the core of
the KJT antiform, (b) very low-grade Late Proterozoic me-
tagreywackes of the Machnín Group, (c) low-grade end-Prot-
erozoic to Early/Middle Cambrian Radèice Group, comprising
metasedimentary and metavolcanic sequences including the
elezný Brod and Rýchory Metavolcanic Complexes (i.e., the
main volcanic piles of the South and East Krkonoe Complex-
es, respectively), and (d) Late Ordovician to Silurian Poniklá
Group, consisting of a low-grade metasedimentary sequence
with subordinate metavolcanic rocks. Only the latter sequence
270 WINCHESTER et al.
abundant chlorite and apparently largely comprise volcani-
clastic material. Samples were obtained from 19 locations on
the south side of the Krkonoe Mts (Fig. 1), selected to test
the chemical variations within the mapped Velká Úpa,
Radèice and Poniklá Groups, and to check the allocation of
these samples to each unit where there is currently some doubt
about their affinities.
Petrography
Metamorphosed clastic sedimentary rocks of the Krkonoe
Jizera Terrane include metapelites, metagreywackes (mica-
ceous metapsammites) and quartzites with varied petrogra-
phy, textural features and compositions. Rocks formerly as-
signed to the Radèice and Poniklá Groups (e.g. Chaloupský et
al. 1989) have been pooled within a single Early Paleozoic
Group as the metamorphosed clastic sediments of both groups
are compositionally identical; in this study it is named the
Vrchlabí Group. The Velká Úpa Group is treated as a separate
lithostratigraphic group based on its presumed Mesoprotero-
zoic age (Chaloupský et al. 1968, 1989).
Velká Úpa Group
Quartzites are dominated by quartz, usually showing an an-
nealed mylonitic texture. Feldspar is absent, but small laths of
muscovite with rare hematite-stained biotite aggregates are
disposed in curving trails, which may record the outline of
former quartz grains before mylonitization induced grain size
reduction. In some quartzites a ribbon texture is developed
with strong alignment of muscovites and accessory epidote,
allanite, hematite and ilmenite.
Micaceous metapsammites exhibit similar textures and min-
eral assemblages, but contain a higher proportion of musco-
vite. Large pleochroic green chlorite grains are present, to-
gether with accessory ilmenite and blue green tourmaline.
Pelitic schists mostly display mylonitic fabrics with strong
mineral alignment. They contain prominent albite porphyro-
blasts, displaying evidence of rotation, associated with chlo-
rite, muscovite and quartz aggregates. Accessory ilmenite, he-
matite, apatite and bottle green tourmaline are characteristic.
Vrchlabí Group
Quartzites are variably mylonitized. Some display a mortar
texture in which large old strained grains are surrounded by
fine-grained recrystallized new quartz, while in others an an-
nealed texture is characteristic. Feldspar is absent, but subor-
dinate muscovite and hematite are present. In some samples
localized hematite staining lends a golden hue to the musco-
vite.
Micaceous metapsammites consist of alternating quartz-rich
and muscovite-rich foliae. The distribution of the quartz-rich
areas suggests that they have replaced large quartz grains dur-
ing mylonitic grain-size reduction. Muscovite-rich areas dis-
play a pervasive crenulation, are associated with minor pale
green chlorite and enclose rounded albite grains. A few grains
of accessory apatite occur.
Pelitic schists are often exceedingly fine-grained. They
dominantly comprise muscovite, quartz and albite, and locally
contain subordinate biotite and pale green chlorite. Hematite
and magnetite are both present. These rocks from the Vrchlabí
Group, in which albite, when present, occurs as elongated ag-
gregates, show a major textural distinction from the albite por-
phyroblastic pelites of the Velká Úpa Group. In all these rocks
early fabrics have been strongly overprinted by mylonitic tex-
tures.
Highly chloritic rocks are also present: their higher chlorite
content may reflect an original basic volcaniclastic content. In
these rocks blue green actinolite is associated with the chlo-
rite, and in some places the actinolite mantles relict blue
crossitic amphibole. These assemblages show that the pre-
served metamorphic grade in the East and South Krkonoe
Complexes is mostly greenschist facies, although relict blue
amphibole suggests that it has overprinted earlier HP-LT
metamorphism. Indeed, in the East Krkonoe Complex as-
semblages characteristics of an earlier blueschist facies meta-
morphism (e.g. Wieser 1978; Patoèka et al. 1996; Patoèka &
Smulikowski 2000) are locally well preserved. By inference,
therefore, the mylonitic greenschist facies fabric in these
rocks may reflect a second rather than a first metamorphic
event, and the foliation might therefore be S2, deformed by a
later S3 crenulation.
Chemical methods
The samples were analysed at Keele University, England,
for 11 major elements and 17 trace elements, using an ARL
8420 X-ray fluorescence spectrometer, calibrated against both
international and internal Keele standards of appropriate com-
position. Analytical methods and precision are described in
Winchester et al. (1992). Fourteen samples were also analysed
by INAA for selected trace elements and the REE at the Labo-
ratory of Nuclear Spectroscopy of the Institute of Nuclear
Physics, AS CR, Prague. The details and precision of the
method are described in Vobecký et al. (1971) and Kuncíø et
al. (1980). Analytical results are shown in Tables 1 and 2.
Results
Interpretation of the compositions of the KJT meta-
morphosed clastic sedimentary rocks was undertaken with
care, as many of the samples display mylonitic fabrics, and all
have been metamorphosed. Many elements, such as the alkali
metals, may therefore have undergone some mobilization dur-
ing metamorphism and the accompanying ductile shearing.
On the accompanying diagrams metapelites generally accept-
ed as part of the Velká Úpa Group are distinguished from
those generally accepted as part of the Vrchlabí Group, to-
gether with those of uncertain affinity (i.e., those variously
mapped as belonging to the Radèice or Velká Úpa Groups,
but which recent remapping has suggested might have been
wrongly assigned) (Figs. 3 to 7).
Chemical comparisons between the various metasedimenta-
ry rocks assigned to the Velká Úpa Group and Vrchlabí
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 271
Group showed that the pelitic schists showed clear distinc-
tions. In contrast, little clear discrimination could be made be-
tween the quartzites and micaceous metapsammites in each
group.
Pelitic schists
A Rb-Na
2
O binary diagram (Fig. 3a) shows the albite por-
phyroblast-bearing Velká Úpa Group metapelites to contain
higher Na
2
O than the other metapelites. On this diagram all
the metapelites of uncertain affinity plot with the Vrchlabí
Group metapelites. A Fe
2
O
3
t
-MgO diagram shows the Mg/Fe
ratio to be higher in Velká Úpa Group metapelites (Fig. 3b).
On this diagram also the metapelites of disputed affinities
plotted with the Vrchlabí Group. Combining these differences
on a Fe
2
O
3
t
/MgO-Na
2
O/Rb diagram (Fig. 3c), separate trends
may be constructed for rocks from the Velká Úpa Group and
Vrchlabí Group, and a similar result can be more conclusively
drawn on a Y/Nb-Fe
2
O
3
t
/MgO diagram (Fig. 3d), which does
not use potentially mobilized elements such as Na and Rb.
These trends show that the Velká Úpa Group and Vrchlabí
Group pelitic schists can be chemically distinguished (with
some reservation with regard to potential mobility of alkali
metals during low-grade metamorphism): they also show that
the unclassified, possibly Radèice Group (cf. Chaloupský
1989) rocks are not easily distinguished from the other
metapelites of the Vrchlabí Group.
The abundance of chlorite in some rocks suggested during
collection that they might contain volcaniclastic material. On
a Ni-TiO
2
binary plot (Floyd et al. 1989) the low Ni character-
istic of most of the samples places them close to a typical
acid-basic magmatic trend (Fig. 4a), suggesting either that
they do contain a significant proportion of volcaniclastic ma-
terial, or that they largely consist of clastic material derived
with little chemical modification from an igneous source.
However, a Sr-Rb diagram (Fig. 4b) shows that the pelitic
schists from all formations do not contain the high Sr charac-
teristic of immature sediments containing plagioclase clasts
derived rapidly from igneous material: indeed Rb/Sr ratios
generally exceeding unity suggest that these sediments were
relatively mature (provided that the Rb and Sr systems were
not significantly modified throughout the rock history). None-
theless, Ni and TiO
2
values are rather low for typical mature
mudstones, and this also suggests that their concentrations
may have been diluted by the addition of acid tuffaceous ma-
terial. Hence their igneous character indicated on Fig. 4a
may result from the addition of a fresh rhyolitic volcaniclastic
component to otherwise mature mudstones.
Fig. 3. Binary diagrams distinguishing the Krkonoe-Jizera Terrane metapelites and showing geochemical trends characterizing the Velká
Úpa and Vrchlabí Groups. Symbols: filled circles Velká Úpa Group metapelites; open triangles Vrchlabí Group metapelites.
272 WINCHESTER et al.
Four metapelitic samples from each group were selected for
REE analysis (samples VU-1, VU-7, VU-10 and VU-11 in Ta-
ble 1, and VL-1, VL-5, VL-8 and VL-14 in Table 2, respective-
ly). All are uniform and contain intermediate SiO
2
concentra-
tions (ca. 60 to 67 wt. %), so according to chemical classifica-
tions of sedimentary rocks (e.g. Blatt et al. 1980) they composi-
tionally correspond to metapelites or pelitic metagreywackes.
Rocks of both lithostratigraphic groups show very similar
trace element distribution patterns compared to the composi-
tion of average continental upper crust (UCC after Taylor &
McLennan 1985) (Fig. 5a,b). In both groups the profile is
characterized by very low Sr contents, and concentrations of
K, Rb, Ba, Th, Nb and Ti, which are approximately equal to
or differ only slightly from UCC. All samples show enrich-
ment of Hf (±Zr): the only differences between the Velká Úpa
and Vrchlabí Group rocks are slightly higher concentrations
of Hf and Zr and quite low contents of P in the latter. Mantle
compatible elements are enriched relative to UCC in the
metapelites of both lithostratigraphic groups, although Sc and
Cr enrichment is somewhat more pronounced (up to two
times) in the Velká Úpa Group rocks (which also include a
single specimen with quite high abundances of Y and Yb).
Hence, the Vrchlabí Group metapelites display higher Th/Sc
values than the Velká Úpa Group ones: 0.88±0.14 (2
σ
) com-
pared to 0.66±0.03, respectively (Fig. 5a,b and Tables 1 and
2). The latter value is below the UCC ratio of these elements
(0.97) (cf. Taylor & McLennan 1985).
The chondrite-normalized (Anders & Grevesse 1989) REE
concentrations in metapelites from the Velká Úpa and
Vrchlabí Groups are characterized by a concave-upward REE
profile, with moderately sloping LREE and flat HREE (Fig.
6a,b). The Vrchlabí Group samples show a somewhat steeper
LREE/HREE gradient Ce
N
/Yb
N
= 6.26±0.99 compared with
Ce
N
/Yb
N
= 5.30±1.14 displayed by the Velká Úpa Group.
Negative Eu anomalies in the metapelites of both litho-
stratigraphic groups are rather small, with Eu/Eu* values cor-
responding to 0.65±0.01 and 0.68±0.02, respectively. The
PAAS-normalized (PAAS Post-Archean Average Austra-
lian Sedimentary) (Nance & Taylor 1976) REE distribution
patterns of the studied metapelites display a level profile in
both groups (Fig. 7a,b).
Micaceous metapsammites
Two micaceous metapsammite samples from the Velká Úpa
and Vrchlabí Groups (samples VU-6 and VL-12 in Tables 1
and 2), with contents of SiO
2
ca. 73 and 74 wt. %, respective-
ly, are present in the completely analysed set of specimens.
On a ternary diagram Na
2
OFe
2
O
3
t
+MgOK
2
O (Blatt et al.
1980) they plot as metamorphosed equivalents of arkoses to
lithic sandstones (arenites) (Fig. 4c). They are only slightly
depleted in trace element abundances relative to the
metapelites (Fig. 5c). Compared to the composition of aver-
age upper continental crust (UCC) they also show trace ele-
ment distribution patterns similar to those of the Velká Úpa
and Vrchlabí Group metapelites, although they differ in some
enrichment of LILE (Large Ion Lithophile Elements) relative
to Sc and Cr, and in several specific features (see below).
Profiles similar to those of the metapelites occur in the REE
chondrite normalized concentrations in the micaceous metap-
sammites of the Velká Úpa and Vrchlabí Groups, with little
distinction between the groups, but with larger negative Eu-
anomalies (Eu/Eu* = 0.41 and 0.50, respectively) (Fig. 6c).
Fig. 4. Diagrams showing primary relations of the Krkonoe-Jizera
Terrane metasediments: a Ni-TiO
2
binary diagram illustrating
the magmatogenic derivation of majority of the metasediments;
b Sr-Rb binary diagram illustrating primary sediment maturity;
c Na
2
OFe
2
O
3
t
+MgOK
2
O ternary diagram discriminating
former sandstone types. Symbols as in Fig. 3, but also including
closed triangles Vrchlabí Group micaceous metapsammites; hor-
izontally divided half circles Velká Úpa Group micaceous
metapsammites; inverted closed triangles Vrchlabí Group
quartzites; vertically divided half circles Velká Úpa Group
quartzites.
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 273
PAAS-normalized REE distribution patterns of the micaceous
metapsammites show a flat profile similar to that of the
metapelites (Fig. 7c).
Too few samples were analysed to show any clear differ-
ence of chemistry between micaceous metapsammites of the
two groups. However, the Velká Úpa Group micaceous
metapsammite (VU-6) is enriched in Zr and Hf, while the
Vrchlabí Group micaceous metapsammite (VL-12) displays
significant enrichment of P, Y and Yb as well a marked nega-
tive Eu anomaly (Figs. 5c and 6c). Hydraulic sorting of heavy
minerals (e.g. Cullers et al. 1987) may explain these features,
resulting from concentrations of zircon in the former two sam-
ples, and of zircon and apatite in the latter specimen.
Quartzites
Six quartzite samples from the Velká Úpa and Vrchlabí
Groups with SiO
2
concentrations ranging from ca. 89 to 94
wt. %) were analysed, of which four (VU-15, VU-17, VL-6
and VL-13 in Tables 1 and 2), also had REE determinations
undertaken. A ternary diagram Na
2
OFe
2
O
3
t
+MgOK
2
O de-
fines the quartzites of both groups as somewhat feldspathic, as
they plot in the arkose field (Fig. 4c). Their trace element
abundances are depleted to under half the content in the
metapelites, and seem to be strongly controlled by hydraulic
sorting of heavy minerals (Fig. 5d). Where the effect of the
latter process is absent, the quartzite (the sample VL-6) shows
trace element distribution patterns normalized to UCC, chon-
drite and PAAS similar to those of the metapelites and mica-
ceous metapsammites, but with lower concentrations owing to
the abundance of silica (Figs. 6d and 7d).
The Velká Úpa Group quartzites are enriched in P, Zr, Hf,
Y and Yb (Fig. 5d), and sample VU-15 shows the largest neg-
ative Eu anomaly (Eu/Eu* = 0.34) among the whole studied
specimens (Fig. 6d). Hydraulic sorting of heavy minerals, e.g.
principally zircon and apatite (and/or any mineral retaining
these elements), seems to be the cause of these characteristics.
The Th/Sc ratios of the quartzites range from parity to 1.5
times the UCC average ratio.
Paleotectonic setting of the metasediment precursors
The metapelites and some micaceous metapsammites of the
Velká Úpa and Vrchlabí Groups are enriched in LILE (with
Fig. 5. Distribution patterns of trace element concentrations in the Krkonoe-Jizera Terrane metasediments normalized to upper continental
crust (UCC) composition after Taylor & McLennan (1985); elements are ordered according to Pearce (1982): a Velká Úpa Group
metapelites; b Vrchlabí Group metapelites; c micaceous metapsammites from both groups; d quartzites from both groups. Symbols
as in Figs. 3 and 4.
274 WINCHESTER et al.
exception of Sr) relative to both ACM (active continental
margin) and PM (passive margin) greywacke types defined by
Floyd et al. (1991) (Figs. 5a,b,c and 8a). They are also less de-
pleted in Nb compared with both ACM and PM types. In their
concentrations of Zr, Hf, Sm, Ti, Y and Yb these metapelites
and micaceous metapsammites are similar to PM (non volcan-
ogenic) greywackes, while in their Sc and Cr contents they re-
semble ACM types.
The metapelites of both groups are generally characterized
by flat PAAS-normalized REE distribution patterns, and usu-
ally show only very small positive Eu anomalies (Fig. 7a,b).
While these features are characteristic of clastic sediments
from mature active margins of Andean type (cf. Bhatia 1985),
the almost identically flat REE patterns of the metapsammites
(metagreywackes and meta-arkoses) as well as those of some
of the quartzites display slight negative Eu-anomalies (Fig.
Table l: Major and trace element abundances in representative samples of the metamorphosed clastic sediments of the Velká Úpa Group
of the Krkonoe-Jizera Terrane. nd not determined.
7c), which are characteristic of passive margin clastic rocks
(Bhatia 1985).
As demonstrated by higher Th/Sc values, the Vrchlabí
Group metapelites are depleted in mantle compatible elements
relative to LILE compared to those from the Velká Úpa Group
(Fig. 5a,b). They also display somewhat higher LREE vs.
HREE fractionation and complementary slightly lower Eu/
Eu* values in chondrite normalized REE profiles (Fig. 6a,b).
These geochemical differences seem to indicate that the
metapelites of the Vrchlabí Group are chemically more remi-
niscent of PM-type clastic sediments (cf. Floyd & Leveridge
1987; Floyd et al. 1991; McLennan et al. 1993).
The Velká Úpa and Vrchlabí Groups differ lithologically
and geochemically from the only KJT metasedimentary se-
quence of known Neoproterozoic age, the Machnín Group of
the KJT autochthonous unit (e.g. Chaloupský et al. 1989;
rock type
pelites and semipelites
psammites
quartzites
sample
VU-1
VU-3
VU-7
VU-9 VU-10 VU-11 VU-12 VU-2
VU-6
VU-8 VU-14 VU-4
VU-5
VU-13 VU-15 VU-17
wt. %
SiO
2
62.55
60.06
64.91
61.79
63.82
62.23
63.32
69.41
72.72
73.71 70.60 86.14
93.88
96.17
91.19
95.72
TiO
2
0.80
0.85
0.82
0.89
0.78
0.81
0.74
0.71
0.83
0.49
0.84
0.51
0.19
0.11
0.03
0.03
Al
2
O
3
17.69
18.64
19.44
18.65
18.78
18.89
17.78
15.12
15.66
12.14 15.49
7.60
3.87
2.56
5.77
3.31
Fe
2
O
3
t
6.36
7.04
4.16
5.71
5.61
6.00
6.02
4.70
3.74
5.98
4.11
2.44
0.84
0.56
0.46
0.08
MnO
0.06
0.06
0.03
0.04
0.03
0.03
0.06
0.05
0.02
0.03
0.01
0.02
0.01
0.01
0.01
0.01
MgO
2.61
2.61
1.80
2.52
2.15
2.31
2.43
2.09
0.83
1.89
1.12
0.46
0.08
0.00
0.01
0.00
CaO
0.87
0.27
0.06
0.24
0.21
0.15
0.68
0.17
0.07
0.14
0.21
0.05
0.04
0.04
0.04
0.10
Na
2
O
3.32
3.47
1.61
2.00
1.85
2.28
2.18
2.44
0.12
1.62
0.08
0.00
0.00
0.00
0.00
0.00
K
2
O
2.96
3.26
4.44
4.41
3.78
3.96
3.63
3.06
3.68
1.88
4.66
1.75
0.92
0.67
1.71
0.68
P
2
O
5
0.19
0.19
0.10
0.18
0.17
0.15
0.17
0.17
0.08
0.14
0.15
0.04
0.02
0.02
0.03
0.02
LOI
2.08
3.12
3.40
3.15
3.34
3.27
2.95
2.62
2.47
2.37
2.45
1.37
0.67
0.40
0.97
0.43
S
0.00
0.00
0.01
0.00
0.00
0.01
0.00
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.00
Total
99.50
99.57 100.79
99.58 100.51 100.09
99.96 100.55 100.22 100.40 99.72 100.38
100.53 100.54 100.23 100.38
ppm
Ba
896
1097
995
1651
829
665
781
1000
529
511
1196
219
125
83
79
100
Cl
23
30
49
21
21
11
9
2
30
19
1
17
5
3
3
nd
Cr
90
90
116
78
74
81
72
72
69
nd
60
26
nd
18
14
17
Cu
21
12
31
20
11
16
27
12
6
nd
6
1
17
nd
nd
nd
Ga
22
22
11
21
21
24
21
18
12
6
18
7
1
2
7
3
Hf
6.1
nd
5.7
nd
5.1 4.5
nd
nd
13.4
nd
nd
nd
nd
nd
0.9
0.9
Nb
18
18
nd
19
15
16
16
14
nd
nd
16
9
nd
2
3
2
Ni
42
38
40
27
27
22
35
14
76
99
30
17
28
8
7
7
Pb
9
15
18
12
47
65
19
20
3
nd
9
10
1
4
4
4
Rb
169
130
201
159
173
188
185
127
189
52
292
98
45
55
121
34
Sc
18
nd
21
nd
19
16
nd
nd
14
nd
nd
nd
nd
nd
1
1
Sr
171
90
14
76
65
84
78
55
nd
20
33
9
nd
7
11
10
Th
12.6
15
12.8
22
12.5 10.7
19
14
16.1
nd
19
12
nd
11
1.4
1.5
V
123
134
148
121
155
159
116
106
105
96
119
32
14
14
5
2
Y
34
23
nd
34
96
41
40
24
nd
2
33
20
nd
11
6
6
Zn
119
109
87
83
95
112
131
84
45
106
59
54
34
16
16
15
Zr
203
175
98
217
180
188
212
198
289
113
337
245
36
57
35
32
La
73.2
0
34
42.7
0
40
53.2
0
41.3
0
12
20
56.1
25
32
13
7
4
1.2
0
2
Ce
89
68
72.8
0
70
88
69.1
0
44
50
98.9
51
48
37
12
8
1.7
0
3.8
0
Nd
61.7
0
32
34.8
0
26
56.5
0
35.7
0
18
30
47.5
22
19
10
22
13
nd
2.2
0
Sm
10.42
nd
6.09
nd
10.86
6.32
nd
nd
7.49
nd
nd
nd
nd
nd
0.2
0
0.38
Eu
2.14
nd
1.27
nd
2.35
1.3
0
nd
nd
1.11
nd
nd
nd
nd
nd
0.03
0.08
Gd
7.61
nd
4.8
nd
10.39
5.34
nd
nd
5.6
0
nd
nd
nd
nd
nd
nd
nd
Tb
1.06
nd
0.66
nd
1.61
0.69
nd
nd
0.83
nd
nd
nd
nd
nd
0.07
0.07
Yb
3.11
nd
2.7
nd
5.73
2.63
nd
nd
3.57
nd
nd
nd
nd
nd
0.5
0
0.4
0
Lu
0.49
nd
0.44
nd
0.87
0.39
nd
nd
0.58
nd
nd
nd
nd
nd
0.07
0.06
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 275
Gehmlich et al. 1997; Kachlík & Patoèka 1998a). The Mach-
nín Group is characterized by abundant metagreywackes dis-
playing for the most part an ACM-like trace element distribu-
tion relative to UCC (Fig. 8b), with higher Th/Sc values
(1.01.1), and stronger LREE/HREE fractionation (Ce
N
/Yb
N
= 6.57.0) than the Velká Úpa and Vrchlabí Groups.
Relating the validity of the results to the geological map
1. The metamorphosed clastic sedimentary rocks of the
Poniklá and Radèice Groups (cf. Chaloupský et al. 1968,
1989) are chemically indistinguishable. These groups could
therefore be combined in a single Vrchlabí Group and proba-
bly correlate with coeval and lithologically similar metasedi-
mentary sequences in the Kaczawa and Rudawy Janowickie
Complexes in Poland (e.g. Teisseyre 1973; Baranowski et al.
1990). However, two facies (subgroups?) are distinguishable
within this group (and may be recognized also in a map scale),
defined by either abundant metavolcanic intercalations, or nu-
merous intercalations of marbles and quartzites within the
dominant monotonous metapelites (Kachlík 1997; Kachlík &
Patoèka 1998b, 1999).
2. Abundant mylonitic fabrics and ductile overthrusts in the
KJT suggest that imbrication and structural repetition is likely
within the Vrchlabí Group (e.g. Kachlík & Patoèka 1998a,b).
Hence the sparse faunal ages obtained from metapelitic and
metacarbonate rocks (e.g. Chlupáè 1993, 1997; Konzalová &
Hrabal 1998; Hladil et al. 1998, 2003) and a few geochrono-
logical datings of metavolcanic rocks (e.g. Bendl & Patoèka
1995; Timmermann et al. 1999) may only provide a broad in-
dication of the age range of the entire sequence from Cam-
brian to Silurian (±Devonian?).
Table 2: Major and trace element abundances in representative samples of the metamorphosed clastic sediments of the Vrchlabí Group
of the Krkonoe-Jizera Terrane. nd not determined.
rock type
pelites and semipelites
psammite
quartzites
sample
VL-1
VL-4
VL-5
VL-8
VL-9
VL-10
VL-11
VL-14
VL-15
VL-16
VU-16
VL-12
VL-6
VL-13
wt. %
SiO
2
66.47
52.02
67.33
59.60
48.09
56.71
57.54
64.43
59.72
63.63
53.22
74.07
92.31
88.79
TiO
2
0.78
1.08
0.79
0.70
1.09
0.90
0.94
0.84
1.04
0.81
0.89
0.28
0.16
0.50
Al
2
O
3
16.78
24.28
15.96
18.29
28.53
22.16
22.58
19.27
22.29
16.52
24.14
15.77
4.33
6.03
Fe
2
O
3
t
6.02
10.21
6.77
5.25
9.10
9.32
7.63
5.99
7.11
6.92
9.07
1.45
0.82
1.61
MnO
0.05
0.06
0.02
0.06
0.13
0.15
0.11
0.03
0.17
0.11
0.35
0.01
0.01
0.02
MgO
1.55
1.98
0.87
1.55
1.98
1.58
1.72
1.80
1.63
2.10
2.36
0.86
0.33
0.30
CaO
0.46
0.08
0.05
2.38
0.11
0.34
0.39
0.14
0.25
0.27
0.41
0.32
0.16
0.06
Na
2
O
0.18
1.28
0.01
1.02
0.80
1.02
1.06
0.63
1.27
1.32
1.27
1.41
0.00
0.00
K
2
O
3.86
3.33
5.94
6.31
5.21
4.67
4.39
5.11
4.38
4.07
4.92
3.54
1.24
1.81
P
2
O
5
0.10
0.16
0.08
0.20
0.09
0.13
0.29
0.09
0.10
0.13
0.14
0.24
0.04
0.04
LOI
3.35
5.09
2.95
4.75
4.80
3.69
3.68
0.98
2.27
3.35
3.90
2.65
0.65
1.05
S
0.00
0.01
0.01
0.00
0.00
0.14
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.00
Total
99.61
99.59
100.79
100.11
99.93
100.81
100.35
99.31
100.22
99.24
100.67
100.61 100.05
100.22
ppm
Ba
839
1081
545
1328
1139
985
925
1001
874
850
1113
1243
136
260
Cl
14
14
21
30
3
60
7
10
14
42
2
28
5
1
Cr
80
138
77
75
127
102
96
82
104
85
88
21
20
30
Cu
13
36
14
39
22
15
24
19
20
30
19
7
nd
nd
Ga
20
29
18
22
35
28
27
22
29
22
32
21
4
6
Hf
5.5
nd
6.9
5.1
nd
nd
nd
11.1
nd
nd
nd
4.2
2
9.7
Nb
19
23
18
18
27
23
21
20
23
20
24
14
4
11
Ni
35
55
30
46
59
51
50
36
42
54
42
22
10
14
Pb
11
15
12
9
28
27
27
20
28
9
24
9
5
7
Rb
214
175
455
182
259
229
218
323
222
178
219
162
80
95
Sc
16
nd
14
19
nd
nd
nd
15
nd
nd
nd
6
2
5
Sr
67
109
14
12
129
111
109
53
116
37
144
97
11
11
Th
13.7
18
14.5
12.3
24
17
21
14.2
18
17
25
12.4
2
8.7
V
118
188
98
105
182
137
150
116
130
158
142
34
16
25
Y
34
38
29
22
37
34
36
31
32
26
30
50
6
18
Zn
108
122
80
186
138
112
118
119
97
211
129
49
24
40
Zr
186
124
233
177
179
152
150
199
177
174
161
130
56
312
La
52
40
56
40.2
0
49
30
33
46.7
0
32
45
62
28.9
0
6.7
0
24.6
0
Ce
77.8
0
95
106.9
0
72
91
56
65
89.7
0
67
91
125
54.3
0
12
46
Nd
43.3
0
37
48
33.8
0
41
34
31
41.9
0
9
44
36
23.8
0
6.5
0
21.2
0
Sm
7.64
nd
7.68
5.03
nd
nd
nd
7.37
nd
nd
nd
5.29
1.12
3.92
Eu
1.48
nd
1.41
0.95
nd
nd
nd
1.43
nd
nd
nd
0.77
0.29
0.58
Gd
5.9
0
nd
4.76
3.53
nd
nd
nd
5.55
nd
nd
nd
6.05
nd
3.49
Tb
0.92
nd
0.78
0.61
nd
nd
nd
0.84
nd
nd
nd
0.98
0.16
0.45
Yb
3.21
nd
2.95
2.64
nd
nd
nd
3.34
nd
nd
nd
4.41
0.67
1.8
0
Lu
0.51
nd
0.48
0.44
nd
nd
nd
0.54
nd
nd
nd
0.62
0.11
0.29
276 WINCHESTER et al.
3. Metapelites from the Velká Úpa Group and the Vrchlabí
Group are chemically distinct. However, chemical distinc-
tions between the groups are less clear in metapsammite and
quartzite lithologies.
4. Many metasediments, especially in the metavolcanic
subgroup of the Vrchlabí Group (Kachlík & Patoèka 1998b)
have a volcaniclastic component probably related to the con-
temporary volcanism associated with the elezný Brod and
Rýchory Metavolcanic Complexes.
5. Micaceous metapsammites are mainly lithic arenite to ar-
kose in composition.
Discussion
Precursors of the Velká Úpa and Vrchlabí Groups were ap-
parently deposited on a passive margin of the peri-Gondwan-
an Saxothuringian microplate. The passive margin originated
during the Cambrian and Ordovician by extension and rifting
of former (Cadomian) active continental margin (part of the
NW margin of the Gondwana supercontinent at the end of
Neoproterozoic). In this paleotectonic scenario (and according
to the above described differences in trace element character-
Fig. 6. Chondrite-normalized REE profiles of the Krkonoe-Jizera Terrane metasediments; normalizing values after Anders & Grevesse
(1989): a Velká Úpa Group metapelites; b Vrchlabí Group metapelites; c micaceous metapsammites from both groups; d quartz-
ites from both groups. Symbols as in Figs. 3 and 4.
istics) the Velká Úpa Group, previously assumed on slender
grounds to be Mesoproterozoic by Chaloupský et al. (1989),
is interpreted to be younger than the only KJT metasedimenta-
ry sequence of documented Precambrian age, the Neoprotero-
zoic Machnín Group of the KJT (e.g. Gehmlich et al. 1997).
The geochemical differences seem to indicate that the
metapelites of the Velká Úpa Group are more ACM- and less
PM-like than those of the Vrchlabí Group.
The chemistry permits two possible relationships between
these two groups. Either (1) the Vrchlabí Group sedimenta-
tion postdated that of the Velká Úpa Group, and there was a
change from active continental margin to passive margin set-
tings, indicated by the differing chemistries of the metapelites
of the two groups, or (2) the two groups were Paleozoic rocks
deposited in different areas with differing source material
which have since been tectonically juxtaposed, with the Velká
Úpa Group deposited proximal to the source area, and the
more distal Vrchlabí Group sediments mixed with volcano-
genic material.
In the KJT stratigraphy a key role is attributed to quartzites,
which are ubiquitous both in the Velká Úpa Group and in the
Vrchlabí Group and appear to rest conformably within the
surrounding metapelites (e.g. Chaloupský et al. 1989; Kachlík
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 277
Fig. 8. Upper continental crust-normalized (values after Taylor & McLennan 1985) profiles of trace element concentrations (a) in continen-
tal arc + active continental margin (ACM) and passive margin (PM) Neoproterozoic and Phanerozoic greywacke averages (after Floyd et al.
1991), and (b) in low-grade metamorphosed greywackes of the Neoproterozoic Machnín Group of the Krkonoe-Jizera Terrane (data after
sample files by F. Patoèka); elements are ordered according to Pearce (1982).
Fig. 7. REE profiles of the Krkonoe-Jizera Terrane metasediments normalized by Post-Archean Average Australian Sedimentary rock
(PAAS); normalizing values after Nance & Taylor (1976): a Velká Úpa Group metapelites; b Vrchlabí Group metapelites; c mica-
ceous metapsammites from both groups; d quartzites from both groups. Symbols as in Figs. 3 and 4.
1997; Kachlík & Patoèka 1998a,b). Recent field studies of the
quartzites help resolve this problem. Locally conglomeratic
quartzite bodies contain abundant blue quartz pebbles (0.1 to
1 cm in diameter) derived from the KJT Cambro-Ordovician
gneisses and metagranites (Kachlík et al. 1999). Velká Úpa
Group conglomeratic quartzites from the Malé Labe Valley
contain pebbles of dark quartz-tourmaline hornfelses known
also from basal Ordovician quartzites in Lusatia where they
are interpreted as pebbles derived from the contact aureole of
the Cadomian Lusatian Pluton (e.g. Chaloupský 1963). Ar-Ar
278 WINCHESTER et al.
isotope geochronology on detrital white micas from quartzite
intercalations from Vysoké nad Jizerou and elezný Brod (in
the Vrchlabí Group) shows cooling ages of 564 Ma and 465
Ma, respectively (Marheine et al. 2000). Thus the blue quartz
pebbles, contact hornfels clasts and the Ar-Ar data on detrital
micas, taken together, suggest that the quartzite source area
comprised meta-igneous rocks of Neoproterozoic to Ordovi-
cian age, and hence the age of deposition of much of the
Velká Úpa and Vrchlabí Group quartzites was no older than
Ordovician.
This sedimentation age of the quartzite precursors fits with-
in the Cambrian to Silurian (±Devonian?) time span of accu-
mulation of the Vrchlabí Group, shown by paleontological
and geochronological dating. If the quartzites are also primary
members of the Velká Úpa Group, their age implies that both
of the KJT groups are broadly coeval. However, the presence
of numerous mylonitic zones and ductile thrusts in the KJT
shows that tectonic imbrication of rocks from both groups oc-
curred. Such imbrication may also have brought rocks with
different protolith ages into contact, while on the larger scale
the Velká Úpa and Vrchlabí Groups were probably juxta-
posed by ductile thrusting, analogous to that proposed along
the Kowary and Kaczorów shear zones by Seston et al.
(2000).
Hence, on the basis of both the geochemistry of the
metapelites and the presence of blue quartz and hornfels clasts
in the locally conglomeratic quartzites, the Velká Úpa Group
must be broadly coeval with the Vrchlabí Group: both are Pa-
leozoic (Cambrian to Silurian, ±Devonian?) in age (Kachlík
& Patoèka 1999; Hladil et al. 2003) and mostly postdate intru-
sion of the late Cambrian Izera and Krkonoe (Kowary) grani-
toid gneisses. In this scenario the Velká Úpa Group sediments
were more proximal, perhaps derived from less deeply dis-
sected part of the source area comprising the Cadomian base-
ment (fossil active continental margin of Neoproterozoic age),
and hence generally display chemical characteristics more
typical of ACM-type clastic sediments.
Conclusions
Metasediments of the Poniklá and Radèice Groups are
chemically indistinguishable. They should be combined in a
single Vrchlabí Group of Cambrian to Silurian (±Devonian?)
age, coeval with similar metasedimentary sequences in the
Kaczawa and Rudawy Janowickie Complexes in Poland. Two
facies are distinguished in the metapelite-dominated Vrchlabí
Group on the basis of the abundance of either metavolcanic
rocks or intercalations of marbles and quartzites. The
metapelites of the Vrchlabí Group have higher Fe/Mg and
lower Na/Rb ratios, are enriched in LILE relative to mantle
compatible elements, in LREE relative to HREE, and only
slightly depleted in Eu compared to those in the Velká Úpa
Group.
Chemical compositions indicate that the sediments com-
prising the Velká Úpa and Vrchlabí Groups were for the most
part derived from and deposited on a Neoproterozoic base-
ment which belonged to the Cadomian active continental mar-
gin of Gondwana. In CambrianOrdovician time this deposi-
tion was in an extensional intracratonic basin, which subse-
quently became a passive margin of the Saxothuringian mi-
croplate after it separated from Gondwana. In our proposed
paleotectonic scenario, the Velká Úpa Group must be younger
than the Neoproterozoic Machnín Group of the KJT autochth-
onous unit. Linking the geochemistry of the metapelites with
the lithology of the quartzites (i.e., the presence of blue quartz
and hornfels clasts in the locally conglomeratic quartzites),
the Velká Úpa Group must be broadly coeval with the
Vrchlabí Group, although deposition of the Velká Úpa Group
was more proximal and sourced by sediment eroded from a
relatively less dissected area of the fossil (Cadomian) active
margin. Both groups are now preserved in different thrust slic-
es, which underwent Variscan metamorphism of different in-
tensities.
However interpreted, the composition of the metasediments
of the Krkonoe-Jizera Terrane also reflects the paleotectonic
evolution of the West Sudetes from an ACM setting at the end
of the Neoproterozoic to a Paleozoic extensional PM setting
that presaged the fragmentation of the NW margin of the
Gondwana supercontinent.
Acknowledgments: These investigations were supported
both by the EU-funded PACE TMR Network (No. ERBFM-
RXCT970136), and Grant A3111102 provided by the Grant
Agency of the Academy of Sciences of the Czech Republic,
which follows the Research Schemes CEZ: Z3013912 (AS
CR) and J13/98:113100005 (Charles University). Hardware
support provided by the IBM Czech Republic to the Depart-
ment of Geology and Paleontology, Charles University is ful-
ly acknowledged. D.W. Emley, P. Greatbatch and D. Wilde
are thanked for analytical technical assistance at Keele Uni-
versity, while in the Czech Republic special thanks are due to
J. Frána at the Laboratory of Nuclear Spectroscopy, Institute
of Nuclear Physics (AS CR) in Øe.
References
Aleksandrowski P., Kryza R., Mazur S. & ¯aba J. 1997: Kinematic data
on major Variscan strike-slip faults and shear zones in the Polish
Sudetes, northeast Bohemian Massif. Geol. Mag. 134, 727739.
Aleksandrowski P., Kryza R., Mazur S., Pin Ch. & ¯alasiewicz J. 2000:
The Polish Sudetes: Caledonian or Variscan? Trans. Roy. Soc. Ed-
inburgh 90, 127146.
Anders E. & Grevesse N. 1989: Abundances of the elements: Meteoritic
and solar. Geochim. Cosmochim. Acta 53, 197214.
Baranowski Z., Haydukiewicz A., Kryza R., Lorenc S., Muszynska A.,
Solecki A. & Urbanek Z. 1990: Outline of the geology of the Góry
Kaczawskie (Sudetes, Poland). Neu. Jb. Geol. Paläont., Abh. 179,
223257.
Bendl J. & Patoèka F. 1995: The
87
Rb-
86
Sr isotope geochemistry of the
metamorphosed bimodal volcanic association of the Rýchory Mts.
crystalline complex, West Sudetes, Bohemian Massif. Geol. Su-
detica 29, 318.
Bhatia M.R. 1985: Composition and classification of Palaeozoic flysch
mudrocks of eastern Australia: implications in provenance and tec-
tonic setting interpretation. Sed. Geol. 41, 249268.
Blatt H., Middleton G. & Murray R. 1980: Origin of sedimentary rocks.
2
nd
edition, Prentice-Hall, New Jersey, 1782.
Bia³ek D. 1998: Aspects of geochemistry of the Zawidów Granodiorite
and Izera Granite arc to rift transition? Geolines 6, 11.
Borkowska M., Hameurt J. & Vidal P. 1980: Origin and age of Izera
METASEDIMENTARY SEQUENCES (WEST SUDETES): PALEOTECTONIC AND STRATIGRAPHIC CONSTRAINTS 279
gneisses and Rumburk granites in the West Sudetes. Acta Geol.
Pol. 30, 121145.
Cháb J. & Vrána S. 1979: Crossite-actinolite amphiboles of the
Krkonoe-Jizera Crystalline Complex and their geological signifi-
cance. Vìst. Ústø. Úst. Geol. 54, 143150.
Chaloupský J. 1963: Conglomerates in the Krkonoe-Jizera Crystalline
Complex. Sbor. Ústø. Úst. Geol. 28, 143190 (in Czech).
Chaloupský J. 1966: Caledonian and Variscan orogeny in the Jetìd
Crystalline Complex. Sbor. Geol. Vìd, Ø. G. 10, 737 (in Czech,
English summary).
Chaloupský J. (Ed.) 1989: Geological map of the Krkonoe and Jizerské
hory Mts. 1:100,000. Ústø. Úst. Geol., Praha (in Czech).
Chaloupský et al. 1968: Geological map of the Krkonoe Mts. National
Park 1:50,000. Ústø. Úst. Geol., Praha (in Czech).
Chaloupský J., Èervenka J., Jetel J., Králík F., Líbalová J., Píchová E.,
Pokorný J., Pomourný K., Sekyra J., Shrbený O., alanský J.,
rámek J. & Václ J. 1989: Geology of the Krkonoe and Jizerské
hory Mts. Geol. Surv. Czech., Prague, 1288.
Chlupáè I. 1993: Stratigraphic evaluation of some metamorphic units in
the N part of the Bohemian Massif. Neu. Jb. Geol. Paläont. Abh.
188, 363388.
Chlupáè I. 1997: Palaeozoic ichnofossils in phyllites near elezný
Brod, northern Bohemia. J. Czech Geol. Soc. 42, 7594.
Chlupáè I. 1998: New paleontological finds in the western part of the
Krkonoe-Jizerské hory Mts. metamorphics and their impact on
stratigraphical and tectonical concepts. Geolines 6, 2930.
Crowley Q.G., Timmermann H., Noble S.R. & Holland J.G. 2002:
Palaeozoic terrane amalgamation in Central Europe: a REE and
Sm-Nd isotope study of the pre-Variscan basement, NE Bohemian
Massif. In: Winchester J.A., Pharaoh T.C. & Verniers J. (Eds.):
Palaeozoic amalgamation of Central Europe. Geol. Soc. London,
Spec. Publ. 201, 157176.
Cullers R.L., Barrett T., Carlson R. & Robinson B. 1987: Rare earth ele-
ment and mineralogic changes in Holocene soil and stream sedi-
ment: a case study in the Wet Mountains, Colorado, U.S.A. Chem.
Geol. 63, 275297.
Cymerman Z., Piasecki M.A.J. & Seston R. 1997: Terranes and terrane
boundaries in the Sudetes, northeast Bohemian Massif. Geol. Mag.
134, 717725.
Dostal J., Patoèka F. & Pin Ch. 2001: Middle/Late Cambrian intraconti-
nental rifting in the central West Sudetes, NE Bohemian Massif
(Czech Republic): geochemistry and petrogenesis of the bimodal
metavolcanic rocks. Geol. J. 36, 117.
Floyd P.A. & Leveridge B.E. 1987: Tectonic environment of the Devo-
nian Gramscatho basin, south Cornwall: framework mode and
geochemical evidence from turbiditic sandstones. J. Geol. Soc.
London 144, 531542.
Floyd P.A., Shail R., Leveridge B.E. & Franke W. 1991: Geochemistry
and provenance of Rhenohercynian sandstones: implications for
tectonic environment discrimination. In: Morton A.C., Todd S.P.
& Haughton P.D.W. (Eds.): Developments in sedimentary prove-
nance studies. Geol. Soc. London, Spec. Publ. 57, 173188.
Floyd P.A., Winchester J.A. & Park R.G. 1989: Geochemistry and tec-
tonic setting of Lewisian clastic metasediments from the Early
Proterozoic Loch Maree Group of Gairloch, NW Scotland. Pre-
cambrian Res. 45, 203214.
Floyd P.A., Winchester J.A., Seston R., Kryza R. & Crowley Q.G.
2000: Review of geochemical variation in Lower Palaeozoic me-
tabasites from the NE Bohemian Massif: intracratonic rifting and
plume-ridge interaction. In: Franke W., Haak V. & Tanner D.
(Eds.): Orogenic processes: Quantification and modelling in the
Variscan Belt. Geol. Soc. London, Spec. Publ. 179, 155174.
Franke W. 1998: Tectonic and plate tectonic units at the North Gondwana
margin: evidence from the Central European Variscides. In: Linne-
mann U. (Ed.): Pre-Variscan Terrane Analysis of Gondwanan Eu-
rope. Schr. Staatl. Mus. Mineral. Geol., Dresden 9, 132134.
Franke W., ¯elaniewicz A., Porêbski S.J. & Wajsprych B. 1993:
Saxothuringian Zone in Germany and Poland: differences and
common features. Geol. Rdsch. 82, 583599.
Franke W. & ¯elaniewicz A. 2000: The eastern termination of the
Variscides terrane correlation and kinematic evolution. In: Franke
W., Haak V., Oncken O. & Tanner D. (Eds.): Orogenic processes:
Quantification and modelling in the Variscan Belt. Geol. Soc. Lon-
don, Spec. Publ. 179, 6386.
Furnes H., Kryza R., Muszynski A., Pin Ch. & Garmann L.B. 1994:
Geochemical evidence for progressive, rift-related early Palaeozo-
ic volcanism in the western Sudetes. J. Geol. Soc. London 151,
91109.
Gehmlich M., Linnemann U., Tichimirova M., Lützner H. & Bombach
K. 1997: Die Bestimmung des Sedimentationsalters cadomischer
Krustenfragmente im Saxothuringikum durch die Einzelzirkon-
Evaporationsmethode. Terra Nostra 97, 5, 4649.
Hladil J., Mazur S., Galle A. & Ebert J.R. 1998: Revised age of the
Ma³y Bo¿ków limestone in the K³odzko Metamorphic Unit (Early
Givetian, late Middle Devonian): Implication for the geology of
the Sudetes. Geolines 6, 2224.
Hladil J., Patoèka F., Kachlík V., Melichar R. & Hubaèík M. 2003:
Metamorphosed carbonate sediments of Krkokoe Mts. and Paleo-
zoic evolution of Sudetic terranes (NE Bohemia, Czech Republic).
Geol. Carpathica 54, 281297.
Horný R. 1964: New graptolites from the metamorphosed Silurian of
the Krkonoe Mts. Piedmont. Èas. Nár. Muz., Odd. Pøírodovìd.
133, 4, 224 (in Czech).
Hoth K. 2000: Diskussionsbeitrag zur lithostratigraphischen Gliederung
der Metasedimente im südlichen und östlichen Krkonoe/
Karkononosze. Z. Geol. Wiss. 28, 211227.
Kachlík V. 1997: Lithostratigraphy and architecture of the elezný
Brod crystalline complex: a result of the Variscan tectono-
deformational processes. Zpr. Geol. Výzk. r. 1996, 3031 (in
Czech).
Kachlík V. & Kozdroj W. 2001: Jetìd Range Unit. In: Kozdroj W.,
Krentz O. & Opletal M. (Eds.): Comments on the Geological map
Lauzitz-Jizera-Karkonozse (without Cenozoic sediments). Säch-
sisches Landesamt für Umwelt und Geologie/Bereich Boden und
Geologie, Freiberg. Panstvowy Institut Geologiczny, Warszawa,
Èeský geologický ústav, Praha, 2731.
Kachlík V. & Patoèka F. 1998a: Cambrian/Ordovician intracontinental
rifting and Devonian closure of the rifting generated basins in the
Bohemian Massif realms. Acta Univ. Carolinae, Geol. 42, 433441.
Kachlík V. & Patoèka F. 1998b: Lithostratigraphy and tectono-
magmatic evolution of the elezný Brod crystalline unit: some
constraints for the palaeotectonic development of the W Sudetes
(NE Bohemian Massif). Geolines 6, 3435.
Kachlík V. & Patoèka F. 1999: Metamorphic complexes of the north-
eastern prolongation of the Saxothuringian Zone Góry Kaczaw-
skie Mts. and Eastern and Southern Krkonoe Mts. Fieldtrip Guide
Exc. C3. In: Brause H. & Hoth K. (Eds.): Tagungsband zur 8. Jahr-
estagund im Görlitz 1999 zum Haupttema Westsudeten Exkur-
sionsführer und Veröffentlichungen. GGW, Berlin, 206, 103113.
Kachlík V. & Patoèka F. 2001: Late Devonian to Early Carboniferous bi-
modal volcanic rocks of the Jetìd Range Unit: constraints on the
development of the Variscan orogenic wedge. Geolines 13, 7475.
Kachlík V., Patoèka F. & Fajst M. 2002: Sheared metagranitoids in the
Jetìd Range Mts.: the role in the westward propagation of the
Variscan orogenic wedge in the West Sudetes. Geolines 14, 4344.
Kachlík V., Patoèka F., Marheine D. & Maluski H. 1999: The deformed
metagranites of the Krkonoe-Jizera terrane: controversies be-
tween protolith ages and stratigraphy. Abstracts of the PACE mid-
term review and 4th PACE network meeting. Geol. Inst.,
University of Copenhagen, Denmark, October 910, 1999, 2122.
Konzalová M. & Hrabal J. 1998: Microfossils from the graphite phyl-
lites of the NE Bohemian Crystalline Complex. Vìst. Èes. Geol.
Úst. 73, 7984.
Kröner A., Hegner E., Hammer J., Haase G., Bielicki K.H., Krauss M. &
Eidam J. 1994a: Geochronology and Nd-Sr systematics of Lusa-
tian granitoids: significance for the evolution of the Variscan oro-
gen in east-central Europe. Geol. Rdsch. 83, 357376.
Kröner A., Jaeckel P. & Opletal M. 1994b: Pb-Pb and U-Pb zircon ages
for orthogneisses from the eastern Bohemia: Further evidence for a
major Cambro-Ordovician magmatic event. J. Czech Geol. Soc.
280 WINCHESTER et al.
39, 61.
Kryza R. & Pin Ch. 1997: Cambrian/Ordovician magmatism in the Pol-
ish Sudetes: no evidence for subduction-related setting. Terra
Nova 7, 144.
Kryza R., Mazur S. & Pin Ch. 1995: The Lesczyniec meta-igneous
complex in the eastern part of the Karkonosze-Izera Block, West-
ern Sudetes: trace element and Nd isotope study. Neu. Jb. Miner-
al., Abh. 170, 5974.
Kuncíø J., Benada J., Øanda Z. & Vobecký M. 1980: Multi-element
standard for routine instrumental activation analysis of trace ele-
ments in rocks and tectites. J. Radioanalytical Chem. 5, 369-378.
Maluski H. & Patoèka F. 1997: Geochemistry and
40
Ar-
39
Ar geochro-
nology of the mafic metavolcanics from the Rýchory Mts. com-
plex (west Sudetes, Bohemian Massif): palaeotectonic
significance. Geol. Mag. 134, 703716.
Marheine D., Kachlík V., Patoèka F., Maluski H. & ¯elaniewicz A.
2000: Variscan polyphase tectonothermal record in the West Su-
detes (Bohemian Massif) deduced from Ar-Ar ages. Program
and Abstracts of the 15th International Conference on Basement
Tectonics, Galicia 2000 Variscan-Appalachian dynamics: The
building of the Upper Palaeozoic basement. La Coruña, Spain,
254257.
Marheine D., Kachlík V., Maluski H., Patoèka F. & ela¿niewicz A.
2002: The Ar-Ar ages from the West Sudetes (NE Bohemian Mas-
sif): constraints on the Variscan polyphase tectonothermal devel-
opment. In: Winchester J.A., Pharaoh T.C. & Verniers J. (Eds.):
Palaeozoic amalgamation of Central Europe. Geol. Soc. London,
Spec. Publ. 201, 133155.
Matte Ph., Maluski H., Rajlich P. & Franke W. 1990: Terrane bound-
aries in the Bohemian Massif: Result of large-scale Variscan
shearing. Tectonophysics 177, 151170.
Mazur S. & Kryza R. 1996: Superimposed extensional and compres-
sional tectonics in the Karkonosze-Isera block, NE Bohemian
Massif. In: Oncken O. & Jenssen C. (Eds.): Basement tectonics.
Kluwer Acad. Publ., Amsterdam, 5166.
Mazur S. & Kryza R. 1999: Mylonites in the K³odzko metamorphic unit
a record of pre-Late Devonian dextral transpression in the West
Sudetes. Geolines 10, 5152.
McLennan S.M., Hemming S., McDaniel D.K. & Hanson G.N. 1993:
Geochemical approaches to sedimentation, provenance and tecton-
ics. In: Johnsson M.J. & Basu A. (Eds.): Processes controlling the
composition of clastic sediments. Geol. Soc. Amer., Spec. Pap.
284, 2140.
Nance W.B. & Taylor S.R. 1976: Rare earth patterns and crustal evolu-
tion. I: Australian post-Archaean sedimentary rocks. Geochim.
Cosmochim. Acta 40, 15391551.
Narêbski W. 1994: Lower to Upper Paleozoic tectonomagmatic evolu-
tion of NE part of the Bohemian Massif. Zbl. Geol. Paläont. 9, 10,
961972.
Oliver G.J.H., Corfu F. & Krogh T.E. 1993: U-Pb ages from SW Po-
land: evidence for a Caledonian suture zone between Baltica and
Gondwana. J. Geol. Soc. London 150, 355369.
Patoèka F. & Smulikowski W. 2000: Early Palaeozoic intracontinental
rifting and incipient oceanic spreading in the Czech/Polish East
Krkonoe/Karkonosze Complex, West Sudetes (NE Bohemian
Massif). Geol. Sudetica 33, 115.
Patoèka F., Fajst M. & KachlíkV. 2000: Mafic-felsic to mafic-ultramaf-
ic Early Palaeozoic magmatism of the West Sudetes (NE Bohemi-
an Massif): the South Krkonoe Complex. Z. Geol. Wiss. 28,
177210.
Patoèka F., Pivec E. & Oliveriová D. 1996: Mineralogy and petrology
of mafic blueschists from the Rýchory Mts. crystalline complex
(Western Sudetes, Bohemian Massif). Neu. Jb. Miner., Abh. 170,
313330.
Pharaoh T.C. 1999: Palaeozoic terranes and their lithospheric bound-
aries within the Trans-European Suture Zone (TESZ): a review.
Tectonophysics 314, 1741.
Pin Ch., Mierzejewski M.P. & Duthou J.L. 1987: Rb/Sr isochron age of
the Karkonosze granite from quarry Szklarska Porêba Huta and de-
termination of its
87
Sr/
86
Sr initial ratio. Przegl. Geol. 35, 512517.
Seston R., Winchester J.A., Piasecki M.A.J., Crowley Q.G. & Floyd
P.A. 2000: A structural model for the western-central Sudetes: a
deformed stack of Variscan thrust sheets. J. Geol. Soc. London
157, 11551168.
Smulikowski W. 1999: Metabasic rocks of the Rudawy Janowickie and
Lasocki Range their significance in the study of metamorphic
evolution of the East Karkonosze Complex (West Sudetes, NE Bo-
hemian Massif). Arch. Mineral. 52, 211274 (in Polish).
Sun S.S. & McDonough W.F. 1989: Chemical and isotopic systematics
of ocean basalts: implications for mantle composition and process-
es. In: Saunders A.D. & Norry M.J. (Eds.): Magmatism in the
ocean basins. Geol. Soc. London, Spec. Publ. 42, 313345.
Svoboda J. & Chaloupský J. 1966: The West Sudeten Crystalline. In:
Svoboda J., Dvoøák J., Havlena V., Havlíèek V., Horný R.,
Chlupáè I., Klein V., Kopecký L., Malecha A., Malkovský M.,
Soukup J., Tásler R., Václ J. & ebera K. (Eds.): Regional geology
of Czechoslovakia I. Geol. Surv., Prague 215278.
Taylor S.R. & McLennan S.M. 1985: The continental crust. Blackwell,
Oxford, 1312.
Teisseyre J.H. 1973: Metamorphic complex of Rudawy Janowickie and
Lasocki Grzbiet ridge. Geol. Sudetica 8, 7129.
Timmermann H. Parrish R.R., Noble S.R., Kryza R. & Patoèka F. 1999:
Single cycle Variscan orogeny inferred from New U-(Th-)Pb data
from the Sudetes Mountains in Poland and the Czech Republic.
Abstracts of the PACE mid-term review and 4th PACE network
meeting. Geological Institute, Univ. Copenhagen, Denmark, Octo-
ber 910, 1999, 24.
Vobecký M., Frána J., Bauer J., Øanda Z., Benada J. & Kuncíø J. 1971:
Radioanalytical determination of elemental composition of lunar
samples. Proceedings of the Second Lunar Science Conference,
The M.I.T Press, 2, 12911300.
Walter H. 2000: Neufunde von sphaerischen Mikrofossilien (?Muel-
lisphaerida, ?Mazuelloiden) im Gebiet des südlichen Krkonoe
und in der Lausitz. Z. Geol. Wiss. 28, 12, 7187.
Wieser T. 1978: Glaucophane schists and associated rocks of Kopina
Mt. (Lasocki Range, Sudeten). Mineral. Polonica 9, 1738.
Winchester J.A. & Floyd P.A. 1977: Geochemical discrimination of dif-
ferent magma series and their differentiation products using immo-
bile elements. Chem. Geol. 20, 325343.
Winchester J.A., Van Staal C.R. & Langton J.P. 1992: The Ordovician
volcanics of the Elmtree-Belledune inlier and their relationship to
volcanics of the northern Miramichi Highlands, New Brunswick.
Canad. J. Earth Sci. 29, 14301447.
Winchester J.A. & the PACE TMR Network Team (contract ERBFMRX-
CT97-0136) (for full PACE list authors and those closely collaborat-
ing see the appendix) 2002: A new interpretation of the Palaeozoic
amalgamation of the Central Europe, based on new geological and
geophysical investigations. Tectonophysics 360, 521.
¯elaniewicz A. 1997: The Sudetes as a Palaeozoic orogen in Central
Europe. Geol. Mag. 134, 691702.