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1

Early Carboniferous (~337 Ma) granite intrusion in Devonian (~400 Ma) ophiolite of the Central-European Variscides

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Kryza R.

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2011

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tom Vol. 55, No. 3

213-222

EN

The Central-Sudetic ophiolites comprise mafic-ultramafic complexes around the E and S edges of the Góry Sowie Massif in SW Poland and are recognized as fragments of Devonian (~400 Ma old) oceanic crust. They contain small rodingite bodies and tectonized granite dykes that potentially can highlight the igneous, metamorphic and structural development of the ophiolitic suites. The granite dykes have been tentatively correlated with the Variscan granitoids of the Strzegom-Sobótka Massif to the north. However, new U-Pb SHRIMP zircon data for granites from the serpentinite quarry at Jordanów show a concordia age of 337 š4 Ma for the main zircon population, and of 386 š10 Ma for minor inheritance. Thus, the age of the granite is considerably older than the ages of the Strzegom-Sobótka granitoids, dated at ~310-294 Ma. The granite dyke has a similar age as some other granitoids found near the ophiolitic fragments, e.g., the Niemcza granitoids to the south, dated at 338 +2/-3 Ma; these older granitoids all represents a relatively early stage of granitoid magmatism recorded in that part of the Variscan Orogen. The age of the granitoid dyke within serpentinites confirms that the Paleozoic ophiolites were incorporated into the continental crust already in early Visean times.

2

POCEEL: Paleozoic Orogenesis and Crustal Evolution of the European Lithosphere, Prague, Czech Republic, October 1-3, 1998

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Kryza R.

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nr 2

3

Cyrkon jako wskaźnik genezy łupków z Czarnowa we wschodniej okrywie granitu Karkonoszy

63%

Murtezi M. , Kryza R.

Przegląd Geologiczny

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2001

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tom Vol. 49 nr 9

815-819

PL

Analiza cech morfologicznych, analiza typologiczna metodą Pupina, oraz mikrosondowe badania chemiczne cyrkonów z łupków kwarcowo-skaleniowych oraz łupków łyszczykowych reprezentujących tzw. "formację łupków z Czarnowa" wskazują na urozmaicony charakter protolitów tych skał. Koncentraty cyrkonowe z pięciu różnych, wyselekcjonowanych próbek były poddane analizie typologicznej: trzy próbki z drobnoziarnistych łupków kwarcowo-skaleniowych z północnej części jednostki Czarnowa, dwie próbki z ciemniejszych i grubiej-ziarnistych łupków łyszczykowych z południowej części tej jednostki. Populacje cyrkonów ze wszystkich analizowanych próbek wykazują duże podobieństwo pod względem ogólnych cech morfologicznych. Znaczące różnice zostały jednak zaobserwowane przy analizie typologicznej: próbki łupków kwarcowo-skaleniowych zawierają cyrkony z dominacją słupa {100} i piramidy {101} (typy S24, S23, S19 oraz S18), podczas gdy w cyrkonach łupków łyszczykowych dominują formy {110} i {211}. Zmienność typologiczna odpowiada zmienności obserwowanej w chemicznej charakterystyce cyrkonów: badane ziarna z łupków łyszczykowych wykazują wyższą zawartość Hf, przeważnie z brzegami wzbogaconymi w Hf względem środka. Duża proporcja kryształów euhedralnych oraz generalny brak tzw. pozornego kąta wygaszania w cyrkonach z wszystkich próbek sugerują pierwotne magmowe źródło pochodzenia materiału tych skał. Lupki kwarcowo-skaleniowe z północy terenu prawdopodobnie reprezentują skały wulkanogeniczne, natomiast łupki łyszczykowe z części południowej zawierają cyrkony typowe dla granitoidów typu S lub dla materiału osadowego otrzymanego z tego typu magmowego protolitu.

EN

The quartzo=eldspathic rocks (so-called "leptynites ") and mica schists of the Czarnów unit in the eastern Karkonosze Complex (West Sudetes) exhibit problematic origin and age. They may represent felsic metavolcanics and metasediments of Neoproterozoic (?) age, and form apparently the country rocks of the Kowary orthogneiss that intruded at ca. 500 Ma ago. To highlight the problematic origin of the Czarnów schists, zircons from a set of representative samples of these rocks were studied. This study included description of morphological features, Pupin 's typological classification and electron-microprobe analyses. Zircon concentrates from 5 different rock samples were first studied using a typology method. Three samples come from fine-grained quartzo-feldspatic schists from the northern part of the Czarnów unit, whereas two samples from coarser-grained and darker mica schists in the southern part of the area. All the studied samples reveal zircon populations with many similarities in morphology. However, considerable differences are ascertained in typological analysis: samples from the quartzo-feldspatic schists have types with dominating {100} prism and {101} pyramide (types S24, S23, S19 and S18), whereas in those from the mica schists forms {110} and {211} prevail. This tvpological variation corresponds to differences observed in chemical characteristics of the zircons: the studied grains from the mica schists display higher Hfcontents, usually with rims richer in Hf The observed large proportion of idiomorphic crystals and a general lack of "apparent extinction angle " in all samples suggest their igneous origin. The quartzo-feldspathic schists of the northern area most probably represent acid volcanogenic rocks, whereas the mica schists in the southern part contain zircons ivpical of S-type granitoids or sedimentary material derived from such igneous protoliths.

4

Late stage Variscan magmatism in the Strzelin Massif (SW Poland): SHRIMP zircon ages of tonalite and Bt-Ms granite of the Gęsiniec intrusion

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Oberc-Dziedzic T. , Kryza R.

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2012

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tom Vol. 56, No 2

225-236

EN

The Gęsiniec composite intrusion in the northern part of the Strzelin Massif (Fore-Sudetic Block, SW Poland) was formed in the course of three late Variscan magmatic episodes: tonalitic I, granodioritic, and tonalitic II/granitic. The age of the Gęsiniec tonalite, 295 š3 Ma, is the same as that of another tonalite body in the southern part of the Strzelin Massif, the Kalinka tonalite. The younger biotite-muscovite (Bt-Ms) granite, in a dyke cutting the Gęsiniec tonalite, has an indistinguishable isotopic age of 295 š5 Ma; it contains, however, inherited zircons with ages between ca. 1.5 Ga to 374 Ma, similar to zircon ages from surrounding gneisses. This suggests that the magmatic protolith of gneisses and the magma of the Bt-Ms granite could have come from similar sources, or that the magma of the Bt-Ms granite was contaminated by the gneisses. Both the tonalite and Bt-Ma granite represent a late stage of the granitoid magmatism in the eastern part of the Variscan orogen.

5

Ambiguous geological position of Carboniferous rhyodacites in the Intra-Sudetic Basin (SW Poland) clarified by SHRIMP zircon ages

63%

Kryza R. , Awdankiewicz M.

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2012

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tom Vol. 56, No 1

55-66

EN

Rhyodacite sheets (the Sady Górne Rhyodacites) in the lowermost part of the Permo-Carboniferous Intra-Sudetic Basin molasse fill have been mapped as intrusives but, later on, based on ambiguous field and petrographic evidence, reinterpreted as lower Carboniferous lavas and tuffs; if so, they would mark the earliest episode of late-orogenic volcanism in the Intra-Sudetic Basin and in the whole Sudetes region in SW Poland. However, re-examination of field relationships and new observations are consistent with an intrusive emplacement of the rhyodacites as conformable to semiconformable, simple to composite sheets. SHRIMP zircon study indicates that the rhyodacites contain rare inherited zircons of ca. 560 Ma, and ca. 470 Ma (or slightly older), and a main population of zircons with an average concordia age of 306.1 š2.8 Ma. This latter age documents the emplacement of the rhyodacites during a mid/late late Carboniferous (Westphalian) stage of volcanism in the Intra-Sudetic Basin in the Central European Variscides. This post-orogenic volcanism was possibly initiated several million years later than previously assumed, and could have comprised a few pulses over a relatively prolonged time span of millions of years.

6

The EUROPROBE TESZ and PACE TMR network Meetings, Prague, Czech Republic, October 4-6, 1998

63%

Kryza R.

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nr 2

7

Late-orogenic magmatism in the Central European Variscides: SHRIMP U-Pb zircon age constraints from the Żeleźniak intrusion, Kaczawa Mountains, West Sudetes

51%

Wachowiak K. , Armstrong R. , Kryza R. , Muszyński A.

Geologia Sudetica

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2008

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tom Vol. 40

1-18

EN

We present new U-Pb isotope data obtained using the sensitive high mass-resolution ion microprobe (SHRIMP) technique on zircon crystals from the Żeleźniak subvolcanic intrusion in the Kaczawa Mountains, West Sudetes, SW Poland. The intrusion comprises shallow-level unmetamorphosed and undeformed fine-grained rhyolites, rhyodacites, and trachyandesites and deep-level medium-grained monzogranites and granodiorites. The surrounding country rocks, thought to be fragments of a Variscan accretionary prism, are blueschist- to subsequent greenschist facies metavolcanic and metasedimentary rocks of the Kaczawa Complex. The Żeleźniak intrusion has been correlated with other late- to post-tectonic Variscan volcanic and plutonic bodies in the region, such as the Karkonosze Granite, but the scarcity and often problematic quality of age constraints and of geochemical data have made such correlations speculative. Our new SHRIMP zircon ages of ~315-316 Ma from the Żeleźniak intrusion probably corresponds to the main magmatic stage. However, a younger age of ~269 Ma, derived from some zircon rims, is more difficult to interpret but might reflect either a much younger igneous event or a hydrothermal episode. The new date of ~315-316 Ma for the undeformed Żeleźniak intrusion also provides an upper age limit for deeper-level tectonic and metamorphic processes in the Kaczawa accretionary prism. Furthermore, the new SHRIMP zircon ages are among the oldest obtained from the volcanic rocks within the Variscan Belt in Central Europe and may correspond to the final stages of the exhumation of the blueschist facies rocks in this part of the orogen.

8

The Sudetic geological mosaic : Insights into the root of the Variscan orogen

51%

Kryza R. , Mazur S. , Oberc-Dziedzic T.

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tom Vol. 52, nr 8/2

761-773

EN

The Sudetes in the NE part of the Bohemian Massif stretch between the NW–SE-trending Odra Fault Zone and Elbe Fault Zone and represent a structural mosaic which was shaped, predominantly, during the Variscan orogeny. They are composed of various geological units, including basement units in which Neoproterozoic to Carboniferous rocks are exposed, and a post-orogenic cover of younger deposits. During the long history of geological research, the Sudetes have become a “type locality” for a range of important geological phenomena, such as granites and orthogneisses, ophiolites and (meta)volcanic sequences, granulites, eclogites and blueschists, nappe tectonics and terrane concepts. In spite of significant recent achievements, many key problems need further study, and a selection of them is proposed in this paper: (a) the presence of older, Neoproterozoic (Cadomian) rocks and their position within the Variscan collage, (b) the character and emplacement setting of Palaeozoic, pre-Variscan sedimentary successions and magmatic complexes (including ophiolites), (c) structural evolution, metamorphism (in particular HP/T grades) and exhumation of deeper crustal blocks during the Variscan orogeny, and (d) post-orogenic development. Future investigations would require an interdisciplinary approach, combining various geological disciplines: structural geology, petrology, geochemistry, geophysics and geochronology, and, also, multilateral interlaboratory cooperation.

9

Variscan multistage granitoid magmatism in Brunovistulicum: petrological and SHRIMP U-Pb zircon geochronological evidence from the southern part of the Strzelin Massif, SW Poland

51%

Oberc-Dziedzic T. , Kryza R. , Białek J.

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tom Vol. 54, No 3

301-324

EN

U-Pb SHRIMP ages of one granodiorite and two tonalite samples from the Strzelin Massif, northern part of Brunovistulicum, reveal three distinct stages of Carboniferrous-early Permian granitoid magmatism: tonalitic I - 324 Ma, granodioritic - 305 Ma and tonalitic II/granitic - 295 Ma. The first stage of magmatism coincided with the first migmatization event which took place shortly after the first deformation. The second stage of granitoid plutonism was coeval with the second migmatization event which produced abundant pegmatites. It took place after compressional phases of the second deformation and was related to decompression at the beginning of tectonic denudation. The third, most abundant stage of magmatism was connected with late extension in that part of the Variscan Orogen.

10

A petrogenetic comparative study of zircons rom the mylonites of the Niemcza Shear Zone and the gneisses of the Góry Sowie Block (SW Poland)

51%

Klimas K. , Kryza R. , Mazur S. , Jendrzejaczyk M.

Geologia Sudetica

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2003

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tom Vol. 35

1-12

EN

The morphological features and typological distributions of zircon in the mylonites of the Niemcza Shear Zone (NZ) and in the gneisses and migmatites of the Góry Sowie Block (GSB), in the NE part of the Bohemian Massif, SW Poland, provide important petrogenetic indicators in the strongly deformed metamorphic rocks. The observed similarities between the zircon populations (combined with other field and petrographic evidence) strongly suggest that at least a part of the mylonites developed at the expense of rocks similar to the GSB gneisses and migmatites. The protoliths of the gneisses and migmatites (both in the GSB and within the NZ) were predominantly of sedimentary character, but the zircons suggest that crustal-type granites (in the case of the NZ gneiss and mylonite protoliths) and hybrid mantle/crustal-type granites (in the case of the GSB migmatite protoliths) could have been important sources for the original, mostly detrital (?) material. The large proportion of zircon grains in the NZ mylonites, showing effects of disintegration, can result from sedimentary abrasion of detrital material, and this apparently corroborates the hypotheses that a part of the NZ mylonites derived from protoliths other (more strongly reworked by sedimentary processes?) than those typical of the gneisses and migmatites of the GSB. However, there is also evidence that mylonitization could have influenced the morphometric features of the zircon crystals, generally increasing the proportion of fractured and broken crystals and, most spectacularly, reducing the mean size of the zircon grains in the mylonites. The controversy remains open and to find better constraints would require further detailed petrological studiem

11

Pre-Late Devonian unconformity in the Kłodzko area excavated: a record of Eo-Variscan metamorphism and exhumation in the Sudetes

51%

Kryza R. , Mazur S. , Aleksandrowski P.

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tom Vol. 32, nr 2

127-137

EN

The results of excavation works aimed at exposing the pre-Late Devonian unconformity in the vicinity of Kłodzko (Middle Sudetes, NE Bohemian Massif) are reported. The unconformity, first described by Bederke in 1924, provides important constraints on the timing of the exhumation of metamorphic complexes in the Sudetes. However, despite its importance, the unconformity is nowhere exposed at present (with the possible exception of the gabbro blocks at one locality - Mt.Wapnica in Dzikowiec), and has been inaccessible for direct observation for decades. Therefore, new excavation works were conceived and done to confirm the unconformity's existence and to describe details of the contact between the metamorphic basement and the Devonian sedimentary cover. Two localities, at Łączna and Gołogłowy, were selected for the excavation, based on detailed mapping and an EM31 conductivity survey. In both localities, four trenches, 2.5-3 m deep and up to 24 m long, were dug across the expected contact zone. Along the trenches in both sites the unconformity was excavated. At each site, the metamorphic rocks are in primary, sedimentary contact with the overlying basal sedimentary breccias and conglomerates. There is no evidence of tectonic disturbance at the contact. This angular unconformity must have formed during a relatively narrow time interval of c. 10-15 Ma, between the early Givetian and late Frasnian or Famennian. This timing is constrained by the late Frasnian?- to Famennian age of the limestones directly overlying the basal conglomerates and by the recently revised early Givetian age of a coralline fauna from the metamorphosed limestones of the Kłodzko Metamorphic Unit at Mały Bożków. The existence of this unconformity implies that at the turn of the Middle and Late Devonian times, freshly deformed and metamorphosed rocks were exhumed and onlapped by sediments of the Bardo sequence, which, eventually, became folded during latest Visean/Namurian times.

12

Józef Zwierzycki, a great geologist of the 20th century (reminiscence 50 year after decease)

51%

Chrząstek A. , Górecka-Nowak A. , Kryza R.

Geologia Sudetica

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2014

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tom Vol. 42

167--180

EN

Professor Józef Zwierzycki was born in1888in Krobia, a small town in Wielkopolska (Great Poland), then under Prussian domination. From 1909 till 1914, he studied mining engineering at the Mining Academy, and geology and palaeontology at the University of Berlin. After graduating and obtaining a doctorate degree in geology, he won the competition for a position of geologist in the Dutch Geological Survey in the Dutch East Indies. He left Europe just on the eve of the World War I. He worked on Java, Sumatra and New Guinea in very difficult field conditions, and his work included: geological and soil mapping, geological prospecting of mineral resources, studying unique palaeontological sites and many volcanoes. During 24 years of work on the Malay Archipelago, Józef Zwierzycki was employed as a "research-explorer", "inspector" and, finally, from 1933 till 1938, the Director of the entire Dutch Geological Survey in the Dutch East Indies. After being retired, he received the highest Dutch state award, the Cross of Oranje-Nassau Order for his scientific achievements and work in the Dutch East Indies. In 1938, Józef Zwierzycki, with all the family, returned to Poland. He got a new job in the Polish Geological Institute in Warsaw. After the outbreak of the World War II, he was responsible for securing the property, archives and collections of the Institute. Józef Zwierzycki was arrested and sent to Auschwitz in 1941. One year later, due to firm efforts made mainly by German geologists, he was released from Auschwitz and transported to Berlin, where as a prisoner, he worked for geological needs. In summer 1944, when he was escorted to the Carpathians, he made a bravura escape and hid in Kraków. With a help from his brother-in-low, Professor Kazimierz Maślankiewicz, he luckily hold out in the hiding place till the liberation of Kraków from German occupation. In May 1945, Józef Zwierzycki came to Wroclaw with a group of professors, mainly of Lvov University and Polytechnics, to secure the remnants of buildings and scientific collections of the high schools, left by Germans in the city. In the same year, he obtained a "habilitation" degree and in 1948 received the title of "ordinary professor". Józef Zwierzycki was an outstanding academic teacher with very wide geological knowledge and enormous professional experience, so he gave lectures in several subjects. The research interests of Professor Zwierzycki were, at that time, mainly connected with mineral deposits in SW Poland. Professor Zwierzycki prepared scientific background for prospection of copper deposits, and is considered as a co-discoverer of these deposits in Lower Silesia. Professor Józef Zwierzycki died in 1961. He is among the greatest Polish geologists of the 20th century.

PL

Profesor Józef Zwierzycki urodził się w 1888 roku w Krobi, małym wielkopolskim miasteczku, wówczas pod zaborem pruskim. W latach 1909-1914 studiował w Berlinie - górnictwo na Akademii Górniczej oraz geologię z paleontologią na uniwersytecie. Po uzyskaniu stopnia inżyniera górnika i doktoratu z geologii wygrał konkurs na posadę geologa-eksploratora w Holenderskiej Służbie Geologicznej w Indiach Holenderskich (dzisiejsza Indonezja), dokąd wyjechał w przededniu wybuchu I wojny światowej. Pracował w bardzo trudnych warunkach terenowych na Jawie, Sumatrze i Nowej Gwinei, sporządzając mapy geologiczne i glebowe, poszukując bogactw mineralnych, badając unikalne stanowiska paleontologiczne oraz liczne wulkany. W czasie 24 lat pracy na Archipelagu Malajskim był geologiem-eksploratorem, inspektorem, a w latach 1933-1938 Dyrektorem całej Holenderskiej Służby Geologicznej w Indiach Holenderskich. Po przejściu na emeryturę, za zasługi dla geologii Holandii, otrzymał najwyższe odznaczenie holenderskie, Order Oranje Nassau. W 1938 roku wrócił wraz z rodziną do Polski i podjął pracę w Państwowym Instytucie Geologicznym w Warszawie. Po wybuchu II wojny światowej pełnił obowiązki dyrektora Instytutu i ratował mienie, archiwa i zbiory geologiczne. W 1941 roku został aresztowany i osadzony w Auschwitz, skąd ponad rok później został zwolniony dzięki wstawiennictwu m.in. geologów niemieckich. Następnie przez dwa kolejne lata przymusowo pracował na rzecz geologii w Berlinie. 1 sierpnia 1944 roku zbiegł eskortującym go żołnierzom w Krakowie i w ukryciu, zorganizowanym przez swojego szwagra - profesora Kazimierza Maślankiewicza, dotrwał do zakończenia wojny. W maju 1945 r. przyjechał do Wrocławia w grupie lwowskich profesorów by zorganizować polskie szkolnictwo wyższe i zabezpieczyć poniemieckie zbiory naukowe. W tym samym roku zrobił habilitację, a w 1948 został profesorem zwyczajnym. Profesor Zwierzycki był wybitnym nauczycielem akademickim, który dzięki bardzo szerokiej wiedzy prowadził wykłady z wielu przedmiotów geologicznych. Powojenne badania naukowe Profesora Zwierzyckiego wiążą się głównie z tematyką złóż surowców mineralnych Dolnego Śląska. Wyznaczył podstawy teoretyczne poszukiwań złóż rud miedzi w południowo-zachodniej Polsce i w związku z tym jest uznany za współodkrywcę złóż miedzi na monoklinie przedsudeckiej. Profesor Józef Zwierzycki, który zmarł w 1961 roku, należy do grona największych polskich geologów XX wieku.

13

The Orthogneiss and Schist Complex of the Karkonosze-Izera Massif (Sudetes, SW Poland): U-Pb SHRIMP zircon ages, Nd-isotope systematics and protoliths

45%

Oberc-Dziedzic T. , Kryza R. , Pin C. , Mochnacka K. , Larionov A.

Geologia Sudetica

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2009

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tom 41

14

Lower Carboniferous bentonites in the Bardo Structural Unit (central Sudetes): geological context, petrology and palaeotectonic setting

45%

Kryza R. , Muszer J. , August C. , Haydukiewicz J. , Jurasie M.

Geologia Sudetica

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2008

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tom Vol. 40

19-31

EN

The Lower Carboniferous Paprotnia beds of the Bardo Structural Unit in the central Sudetes, composed predominantly of mudstones with Upper Viséan fossils, include several bentonite layers. The bentonites, composed mainly of kaolinite, illite/smectite and smectite, with minor amounts of quartz, calcite and iron hydroxides, also contain abundant zircons, the features of which indicate their volcanic derivation. The main population of the zircons yielded a SHRIMP U-Pb age of ~ 334 Ma corresponding with, and numerically constraining, the biostratigraphic data. The field evidence, biostrati- graphic and geochronological results, together with mineralogical data from the bentonites, indicate continental margin-type sedimentation and contemporaneous volcanic (andesitic-rhyolitic) activity in the neighbouring region during the ongoing Variscan orogeny in central Europe in Late Viséan times.

15

Conferences

45%

August C. , Kryza R. , Awdankiewicz M. , Breitkreuz C. , Bartz W.

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2006

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tom 38

16

Gneiss protolith ages and tectonic boundaries in the NE part of the Bohemian Massif (Fore-Sudetic Block, SWPoland

45%

Oberc-Dziedzic T. , Kryza R. , Klimas K. , Fanning M. C. , Madej S.

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2005

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tom Vol. 49, No. 4

363--378

EN

Published geochronological data, petrology, geochemistry and geological context of orthogneisses in the Strzelin and the Stachów complexes (NE-part of the Fore-Sudetic Block), together with structural observations help to locate the northern extension of the boundary between the East and West Sudetes within the poorly exposed NE margin of the Bohemian Massif. The Strzelin complex, in the east, comprises the Strzelin gneiss, with zircon ages of 600š7 and 568š7Ma, and the Nowolesie gneiss with a mean zircon age of 1020_ 1Ma. The Stachów complex to the west, which forms several tectonic klippen in the Strzelin Massif and in the Lipowe Hills Massif, contains the Gościęcice gneiss and pale Stachów gneiss, both yielding Late Cambrian zircon ages (~500š5 Ma). The orthogneisses in both complexes correspond to peraluminous S-type granites, but have different inherited zircon ages and display contrasting trace element characteristics, indicating different sources and petrogenetic histories. Based on the ages, petrology and overall geological context, the Strzelin orthogneiss is similar to the Keprník orthogneiss of the East Sudetes, whereas the orthogneisses of the Stachów complex correspond to rocks known from theWest Sudetes (e.g. the Izera and Śnieżnik orthogneisses). The Stachów and the Strzelin complexes are separated by the Strzelin Thrust, which may be interpreted as the northern extension of the boundary between the East and West Sudetes, i.e. part of the boundary between the Brunovistulian and Moldanubian terranes of the NE part of the Bohemian Massif.

17

Litologia i geneza zmetamorfizowanych skał osadowych i wulkanicznych jednostki Chełmca (Góry Kaczawskie)

38%

Baronowski Z. , Haydukiewicz A. , Kryza R. , Lorens S. , Muszyński A. , Urbanek Z.

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tom Vol. 31, nr 1

33-59

EN

Based on detailed drill core studies from fourteen boreholes (up to 1500 m deep) and on field observations, the Chełmiec tectonic unit in the northern part of the Kaczawa Mts appears to contain two types of tectonostratigraphic elements. The first is fragments of a stratigraphic sequence, composed mainly of dark muddy slates (metamudstones) and variegated laminated silty-clayey slates (both considered as Ordovician), and of volcaniclastic rocks, greenstones and dia-bases. The second element is represented by mélange bodies which consist of dark muddy slates (matrix) enclosing fragments of various lithologies: dark siliceous and graphitic slates, light siliceous slates, quartzites, greywackes, variegated silty-clayey slates etc. (probably Upper Devonian or Lower Carboniferous). Due to the lack of biostratigraphic evidence, the stratigraphic subdivision is based on lithological criteria. Using e.g. the rule of superposition and analysis of lithological contacts and sedimentary and volcanogenic structures, the stratigraphic succession was defined, and three informal lithostratigraphic units were distinguished: (a) an association of metamudstones and diabases, (b) an association of metavolcaniclastic rocks (both within the stratigraphic sequence), and (c) a mélange association. The dark metamudstones and variegated silty-clayey slates of the association of metamudstones and diabases are interpreted as turbidites. The volcaniclastic rocks, of clearly epiclastic character, were delivered episodically from marginal parts of the basin or volcanic heights by denser turbiditic currents and other types of gravity flows. Simultaneously, volcanic activity occurred within the basin itself producing basaltic lavas (now observed as subvolcanic diabases and effusive greenstones), which geochemically correspond to recent mildly alkaline within-plate basalts. The geotectonic setting of the basin is difficult to define precisely but the sequence was probably emplaced in an outer fan or in a basin at a continental margin. The mélange represents a later stage of the evolution of the Kaczawa Complex. Most probably, it was deposited from gravity flows and slumps in a trench or on a trench slope. Its origin is thought to have been connected within the formation of a Variscian accretionary prism in Late Devonian and Early Carboniferous times. The rock complex of the Chełmiec Unit experienced several stages of deformation during the Variscian orogeny. The first event resulted in a system of thrusts (and associated folds?) and it was related to (or partly preceeded by) the formation of mélange. It is likely that deformation at this stage (and in particular in its later phase) took place under blueschist facies conditions. The second deformation event, probably under greenschist facies conditions, was associated with folding which steepened the earlier foliation and produced new asymmetric folds. The third deformation event, partly under semi-brittle/brittle conditions, is responsible for new thrusts cutting the earlier structures and the formation of large open folds, such as the Bolków-Wojcieszów antiform. The deformation of the rocks of the Chełmiec Unit was associated with greenschist facies metamorphism. In general, primary sedimentary and volcanic structures are well preserved in the rocks of this unit which often seem to have suffered weaker deformation and metamorphism than that observed in other units of the Kaczawa Mts. No clear evidence of the early high-pressure episode which is widespread in other tectonic units of the Kaczawa Complex has been found in the Chełmiec Unit so far.

18

In situ growth of monazite in anchizonal to epizonal mudrocks: first record from the Variscan accretionary prism of the Kaczawa Mountains, West Sudetes, SW Poland

38%

Kryza R. , Zalasiewicz J. A. , Charnley N. , Milodowski A. E. , Kostylew J. , Tyszka R.

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tom Vol. 36

39-51

EN

We report the first occurrence of diagenetic or low grade metamorphic monazite from the Palaeozoic mudrock successions of the Kaczawa Complex of the West Sudetes, Poland. Where observed in relation to the enclosing mudrock, this monazite comprises tiny irregular grains, less than 20 microns in diameter, intergrown with the surrounding matrix minerals. This monazite resembles previously described examples of diagenetic monazite from elsewhere in the world in mostly possessing low contents of Th and U but differs in forming much smaller grains, which show only slight zonation of rare earth elements (REEs). Some of the monazite grains studied also appear to have formed synchronously with the cleavage, perhaps a function of early deformation and fluid release in an accretionary prism environment. Relatively Th-rich cores, and an association with altered detrital biotite in some instances, suggests that at least some of the in situ monazite growth might have taken place as overgrowths on primary detrital monazite particles.

19

Litologia i geneza zmetamorfizowanych skal osadowych i wulkanicznych jednostki Chelmca [Gory Kaczawskie].

38%

Baranowski Z. , Haydukiewicz A. , Kryza R. , Lorenc S. , Muszynski A. , Urbanek Z.

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nr 1

33-59

20

Jozef Oberc (July 28, 1918 - November 22, 2008)

38%

Kryza R.

Geologia Sudetica

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2009

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tom 41