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1
Content available Permian versus Jurassic geotectonic position of the Lhasa block  – facts and controversies
Krobicki Michał, Golonka Jan, Starzec Krzysztof, Iwańczuk Joanna
Geotourism / Geoturystyka
|
2023
|
nr 1-2 (72-73)
38--38
EN
The Cimmerian Continent (or Cimmeria, Cimmerian terrane, Cimmerian blocks) was detached from eastern Gondwana in the Late Paleozoic as a sliver/ribbon of continental strip rifting elements. Recently, these elements belong to an almost continuous long belt (ca. 13,800 km) from central Italy trough Greece, Turkey, Iran, Afghanistan, Tibet, SW China, Myanmar, Thailand up to Indonesia (Sumatra). The palaeogeographic position and relationship of some elements during Permian-Mesozoic times is still matter of discussion. The Qiangtang and Lhasa blocks (present-day Tibet) belong to these elements and their location in space and time and their relationship causes a lot of controversies. Their position alongside eastern Gondwana in the mid-Early Permian (ca. 290–285 Ma) are suggested both by palaeomagnetic and facies studies. Palaeomagnetic studies indicated this position one decade ago, which has been confirmed by recent studies. The Cimmerian Continent [Iran (Alborz)-Qiangtang-Baoshan-Tengchong-Sibumasu] was separated from the Gondwanian part of Pangea during mid-Early Permian time by rifting and drifting. Northwards migration of it took place during Permian-Triassic times caused wide opening of the Bangong‐Nujiang Tethyan Ocean and closing of the Paleotethys Ocean but the Lhasa block was still southern margin of the Bangong‐Nujiang Ocean. The Triassic Indosinian Orogeny has been one of the most spectacular geotectonic event reflecting collision of this continent with Indochina block and closure of the Paleotethys Ocean. The separation of the Lhasa block from Gondwana is enigmatic but most probably took place during earliest Jurassic times. This separation was followed by quick shift northward. Intensive sedimentological studies of the Late Triassic (Carnian-Norian) several flysch-type turbidites in the eastern Tethyan Himalaya (e.g. Qulonggongba, Pane Chaung, Langjiexue, Quehala, Duoburi formations/groups) indicate that their provenance was connected with Lhasa block, which has been their source area during early-stage evolution of the Neotethys. The late Early Permian rift-related basaltic magmatism in northern Baoshan (in SW China) and sourrounding regions was connected with first step of separation from Gondwana margin of this block (together with South Qiangtang and Sibumasu blocks and simultaneously with opening of the Bangong‐Nujiang Ocean before the Middle Permian)  – independently of Lhasa block which was separated later, the most probably during Late Triassic or Triassic/Jurassic transition time with very wide space of the Bangong‐Nujiang Tethyan Ocean between Qiangtang and Lhasa blocks (2,600 km ±710 km  – 23.4° ±6.4° during the Middle Jurassic with its maximum width in the Late Triassic). From the palaeobiogeographic point of view, the worldwide distribution of Pliensbachian-Early Toarcian large bivalves of the so-called Lithiotis-facies, dominated by Lithiotis, Cochlearites, Litioperna genera revealed by the authors’ studies, indicates very rapid expansion of such type of bivalves alongside southern margin of Neotethys, and could be good evidence of palaeogeographic position of the Lhasa block in this time. Himalayan and Tibetan (Nyalam area) occurrences of Lithiotis and/or Cochlearites bivalves could help to place the Lhasa block nearby the Gondwana during Early Jurassic times. This palaeobiogeographic research contradict another interpretation based on different fossils (Permian fusulinids and brachiopods) interpreted as subtropical fauna, which could occur in low subtropical latitudes together with other parts of the Cimmerian Continent.
2
Content available Geological origin of the Permian bedded chert succession distributed in Central Plain of Thailand
Kamata Yoshihito, Phromsuwan Waraphorn, Ueno Katsumi, Charoentitirat Thasinee, Sardsud Apsorn
Geotourism / Geoturystyka
|
2023
|
nr 1-2 (72-73)
33
EN
The geotectonic divisions, which are distributed as narrow zones in the north-south direction, are clear in the northern Thailand, but not clearly recognized in the Central Thailand. The Chao Phraya Plain, which occupies the central part of Thailand, is broadly covered with Quaternary sediments. Therefore, the basement rocks of the Paleozoic and Mesozoic are scattered in the form of residual mounds, and due to the lack of stratigraphic and age-determination data, the geological origin of these rocks have been not sufficiently discussed. In this presentation, we will report the results of a study on the geological belongings of bedded chert sporadically exposed in the Chao Phraya Plain, Central Thailand by the microfossil age and geochemical characteristics. The study areas are Thung Saliam (TS) (50 km northwest of Sukhothai) in the northern part of the plain and the Nakorn Sawan–Uthai Thani (NS-UT) area in the central part of the plain. About 20 outcrops of chert were surveyed in both areas. The cherts are distributed in scattered, and most of the cherts are recrystallized and are considered to have undergone contact metamorphism. Chert of the TS is well-bedded with red and the direct contact relationship is unknown, but tuff and limestone (marble) are exposed around it. Chert of the NSUT is also well-bedded with red, black, gray and milky white in color. Altered slatey shale and sandstone accompany the chert and form monadnocks. These cherts might be categorized into typical pelagic cherts because they contain radiolarian tests and sponge spicules in a matrix consisting of very fine clay minerals and microcrystalline quartz, and do not contain coarse-grained terrigenous materials. Sashida & Nakornsuri (1999) reported the occurrence of Pseudoalbaillella simplex, Ruzencevispongus sp., and so on from the TS chert and they assigned their age to Wolfcampian. Whereas, Saesaengseerung et al. (2007) report radiolarian occurrence of the Ps. loemntaria Assemblage (Artinskian) and Follicucullus scholasticus Assemblage (Capitanian-Wuchiapingian) from the NS-UT chert. Whole-rock chemical analysis was performed on three sections their ages were determined by radiolarians. In the Chondrite-normalized REE pattern, TS chert indicates negative anomaly of Ce, and NS-UT chert shows relatively flat and profile of the downward-sloping in the LREE. The geological age of the study sections and their REE patterns are similar to those observed in the Sa Kaeo area in southeastern Thailand. The Permian bedded cherts exposed in TS and NS-UT areas are often accompanied by thin layers of fine-grained siliciclastics and tuff, which are weakly metamorphosed and foliated. Since the chert itself has a relatively thin thickness (several meters to 10–20 m) in each outcrop, and basically has a north-south strike. These cherts occurrence and lithofacies of both areas are similar and indicate that cherts of both areas are geologically comparable as pointed out by Ueno et al. (2012). Ueno et al. (2012) clarified that the central part of Thailand, where the geotectonic division was unclear, can be divided into three geotectonic units from west to east: Sibumasu Block, Sukothai Zone and Indochin Block. However, the origin of the Permian chert has not been clarified. Paleozoic and Mesozoic cherts distributed in Thailand remind us bedded cherts deposited in the Paleo-Tethys from the Devonian to the Triassic. However, no cherts other than the Permian have been reported in the central part of mainland Thailand. Instead of the Paleo-Tethys chert, the Sa Kaeo-Chanthaburi suture and the Nan-Uttaradit suture are well-known as geological units containing Permian chert in southeastern Thailand. These sutures have been understood as a closed remnant of the Permian to Triassic back-arc basin stretched between the Indochina Block and the Sukhothai Arc. The fact that the Permian cherts of the central plain are distributed in the eastern part of the Sukhothai Zone and near Indochina Block suggests that these Permian cherts comparable to the Permian chert of the Sa Kaeo-Chanthaburi Suture. In addition to the geological evidence, the geochemical features of the Permian chert represented by the REE pattern are similar to those of the Permian chert in the Sa Keo area. Line of evidence mentioned above suggests that the Permian bedded chert distributed the central Thailand (TS and NS-UT areas) have originated to the Permian chert of the Sa Kae-Chanthaburi or Nan-Uttaradit sutures which is a remnant of backarc basin.
3
Content available Kopuła orlicko-śnieżnicka w świetle rozważań tektonicznych
Cymerman Z.
Przegląd Geologiczny
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2016
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Vol. 64, nr 10
814--830
EN
The paper presents tectonic considerations on the geology of the Orlica-Śnieżnik Dome (OSD), based on the published geotectonic, structural and kinematic data and reports on the OSD geotectonic setting, relating to the evolution of the Variscan collisional belt. Further progress has been done in the recognition of the structure and evolution of the OSD, and for many decades the dominant structural geology has been replaced with multithreading researches. However, the current tectonic interpretations are matched against pre-established schemas of structural evolution of the OSD. The OSD is most likely a fragment of the Moldanubian Terrane with the Variscan collisional sutures. The dextral transpression in a general shear regime and with the participation of strain partitioning has formed a thrust sheet package with the dominant tectonic transport top-to-the NNE, N and NW, with the exception of the NE part of the OSD. The development of regional-scale ductile shear zones in the OSD took place during the progressive tectono-metamorphic evolution from about 360 to 335 Ma. These processes resulted from the highly oblique collision of the Moldanubian Terrane (with the OSD) with the Brunovistulicum on the east and the Tepla-Barrandian Terrane on the W, and with a frontal collision with the Central Sudetic Terrane on the N.
4
Content available Does the East European branch of the Caledonides exist?
Mizerski W., Stupka O., Olczak-Dusseldorp I.
Biuletyn Państwowego Instytutu Geologicznego
|
2012
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nr 449
109--117
EN
Since the beginning of the introduction of the concept of the East European branch of the Caledonides by Limanowski (1922), there has been much discussion on the trend of this branch towards the southwest of the East European craton. The extreme interpretations were given by Stille (1950), and later by Dadlez (1994). According to those authors, the East European branch of the Caledonides could trend along the entire course of the south-eastern boundary of the East European craton, from the western Baltic Sea to Ukraine. Analysis of existing geological data, in relation to the current geotectonic theories, puts in doubt the existence of this branch. The proved Caledonian structures, which could be considered as orogenic, are located exclusively in the West Pomeranian segment of the East European craton foreland. The other parts of the foreland should be considered either a lowered marginal edge of the craton or blocks of Avalonian origin.
PL
Od początku wprowadzenia pojęcia wschodnioeuropejskiej gałęzi kaledonidów przez Limanowskiego (1922) trwa dyskusja dotycząca przebiegu tej gałęzi na południowy zachód od kratonu wschodnioeuropejskiego. W skrajny sposób przedstawiał go Stille (1950), a później Dadlez (1994). Według nich wschodnioeuropejska gałąź kaledonidów przebiegałaby wzdłuż całej południowo-wschodniej granicy kratonu wschodnioeuropejskiego, od zachodniego Bałtyku po Ukrainę. Analiza istniejących danych geologicznych, w nawiązaniu do obowiązujących dzisiaj teorii geotektonicznych, stawia w wątpliwość istnienie tej gałęzi. Udokumentowane struktury kaledońskie, które można by uznać za orogeniczne, znajdują się wyłącznie w zachodniopomorskim segmencie przedpola kratonu wschodnioeuropejskiego. Pozostałe fragmenty tego przedpola trzeba uznać bądź za obniżoną, brzeżną krawędź kratonu, bądź za bloki pochodzenia awalońskiego.
5
Content available Jurajskie i kredowe dajki neptuniczne w północnej Tetydzie i na obszarze pery-Tetydy - reperkusje geotektoniczne
Krobicki M., Golonka J., Kucharski J.
Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
|
2008
|
T. 34, z. 3/1
185-188
6
Przestrzenne modele litosfery w strefach aktywnych krawędzi kontynentów i ich znaczenie geotektoniczne.
Wiktorowicz J., Zagożdżon P.
Prace Naukowe Instytutu Górnictwa Politechniki Wrocławskiej. Konferencje
|
2007
|
Vol. 120, nr 49
305-314
PL
W artykule przedstawiono wyniki cyfrowego modelowania struktur geotektonicznych - bloków litosfery pogrążających się w płaszczu, w obrębie tzw. aktywnych krawędzi kontynentów (rejony rowów oceanicznych: Atakamskiego, Kurylsko-Kamczackiego i Kermadec-Tonga). Przeanalizowano położenie wyselekcjonowanych ognisk wstrząsów sejsmicznych, na tej podstawie wygenerowano modele przestrzenne i poddano je interpretacji. Stwierdzono, że wszystkie modele ukazują wyraźnie nieciągłą strukturę litosfery oceanicznej w rejonach analizowanych aktywnych krawędzi kontynentów, na głębokościach 30-700km.
EN
The paper presents results of three-dimensional models of geotectonic structures - the blocks of lithosphere sinking in Earth mantle in the so called active Continental margins (in the area of the ocean trenches: The Peru-Chile, The Kuril-Karnchatka and The Kermadec-Tonga). The positions of selected earthąuakes focus have been analyzed. The created 3D models have been interpreted. Ali models show the good visible discontinuous structure of ocean lithosphere in analyzed active Continental margins, at the depth of 30-700 km.
7
Content available Geotectonic, seismicity and seismotectonic of the Dinarides of Bosnia and Herzegovina
Hrvatović H.
Reports on Geodesy
|
2006
|
z. 5/80
73--91
8
Content available remote Geodynamics of Central Europe. Current status of geotectonic investigations in Central Europe
Glazek J., Liszkowski J., Śledziński J., Vyskocil P.
Reports on Geodesy
|
2006
|
z. 4/79
13-15
EN
The report contains the description of monitoring of recent crustal movements in the European region covered by the CEGRN stations with highlighting the geologic, geophysical and geodetic aspects of studies carried out by European scientific institutions. The report includes the information coming from different sources and in particular from studies performed by the CERGOP-2/Environment work package subgroups WP10.1 - WP10.7. These sub-groups currently arranged, planned and organised programmes of their activities in particular regions in a fully independent, self-determining and "sovereign" way. So the report was currently updated by the results of investigations of the sub-groups WP10.1-WP10.7. Since all chairmen of work packages were obliged to report their activities at the EGU-CEI symposia in April every year it was expected that the three main inputs of new results of investigations would be available in April 2004, April 2005 and April 2006. The chairmen of work packages had also to concisely report the activities of their sub-groups at the CERGOP-2 Working Conferences that were organised every year in fall time. So, also a short updating of the Pilot Report was possible after the CERGOP-2 fall conferences.
9
Content available Zachodni i południowy zasięg kratonu wschodnioeuropejskiego
Mizerski W., Stupka O.
Przegląd Geologiczny
|
2005
|
Vol. 53, nr 11
1030-1039
EN
The problem of the western and southern borders of the East European Platform is still subject to debate; different authors variously put this border on the geological maps of Europe. The deepness of the crystalline basement between the T–T zone and the Variscan orogen and within the so-called Scythian Platform makes recognizing the geotectonic structure of the area difficult. There are relatively few and small regions with rocks older than Mesozoic. There is no direct access to Precambrian strata over most of the area. Most structural information is provided by geophysical methods, but they do not allow to date the age of consolidated basement. The paleomagnetic studies of the area give equivocal results. Our analysis of available materials from between the T–T zone and the Variscan orogen and the Scythian Platform suggests that the Precambrian Platform has a larger extent than it was generally assumed. The platform extends westwards even as far as the front of the Variscan orogen, and to the SWand S it may reach the Alpine folded structures.
10
Content available remote Geodynamics of the Balkan Peninsula within the framework of CERGOP-2
Milev G., Vassileva K.
Reports on Geodesy
|
2004
|
nr 2/69
97--104
EN
The characteristics of the Balkan Peninsula in geodynamic respect are briefly outlined. The necessity, aims, prerequisites, concepts, methodology and stages of geodynamic investigations are presented. The expected results are formulated. The activities performed so far and the obtained results are discussed. A generalized program for further investigations is developed.
11
Content available remote Determination of local recent movements in Slovenia
Kogoj D., Poljak M., Vodopivec F.
Reports on Geodesy
|
2004
|
nr 2/69
133--139
EN
Slovenia is situated in a region with strong earthquakes. In addition to international cooperation in CERGOP II, local measurements of recent movements are performed in Slovenia. The results of measurements of large power locations, i.e. of Coal Mine and Steam Power Station Velenje and Nuclear Power Station Krsko, are presented.
12
Content available remote Current geotectonic investigations in Central Europe. CERGOP Workpackage WP.10 Progress Report
Śledziński J., Vyskočil P.
Reports on Geodesy
|
2004
|
nr 2/69
65--72
13
Content available remote Synklinorium warszawskie jako przykład struktur zawodnionych możliwych do wykorzystania na PMG
Piesik W., Zamojcin J.
Wiadomości Naftowe i Gazownicze
|
1999
|
R. 2, Nr 9 (17)
9-10
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