Age, evolution and tectonic history of the Highland Border Complex, Scotland

1984 ◽  
Vol 75 (2) ◽  
pp. 113-133 ◽  
Author(s):  
Gordon B. Curry ◽  
B. J. Bluck ◽  
C. J. Burton ◽  
J. K. Ingham ◽  
David J. Siveter ◽  
...  
Keyword(s):  
Regional Scale ◽  
Plate Boundary ◽  
North American Plate ◽  
Tectonic History ◽  
Lower Ordovician ◽  
Northwestern Margin ◽  
Comprehensive Survey ◽  
History Of ◽  
Early Palaeozoic ◽  
Western Ireland

I. ABSTRACT: Research interest in the Highland Border Complex has been pursued sporadically during the past 150 years. The results and conclusions have emphasised the problems of dealing with a lithologically disparate association which crops out in isolated, fault-bounded slivers along the line of the Highland Boundary fault. For much of the present century, the debate has centred on whether the rocks of the complex have affinities with the Dalradian Supergroup to the N, or are a discrete group. Recent fossil discoveries in a wide variety of Highland Border rocks have confirmed that many are of Ordovician age, and hence cannot have been involved in at least the early Grampian deformational events (now accurately dated as pre-Ordovician) which affect the Dalradian Supergroup. Such palaeontological discoveries form the basis for a viable biostratigraphical synthesis. On a regional scale, it is apparent that the geological history of the Highland Border rocks must be viewed in the context of plate boundary tectonism along the entire northwestern margin of Iapetus during Palaeozoic times.II. ABSTRACT: Silicified articulate brachiopods from the Lower Ordovician (Arenig) Dounans Limestone are extremely rare but the stratigraphically diagnostic generaArchaeorthisSchuchert and Cooper, andOrthidiumHall and Clarke, have been identified. In addition, three specimens with characteristic syntrophiid morphology have been recovered. Inarticulate brachiopods are known from Stonehaven and Bofrishlie Burn near Aberfoyle, and have also been previously recorded from Arran.III. ABSTRACT: Micropalaeontological investigation of the Highland Border Complex has produced a range of microfossils including chitinozoans, coleolids, calcispheres and other more enigmatic objects. The stratigraphical ranges of the species lie almost entirely within the Ordovician and reveal a scatter of ages for different lithologies from the Arenig through to the Caradoc or Ashgill, with a pronounced erosional break between the Llandeilo and the Caradoc.IV. ABSTRACT: A Lower Ordovician (Arenig Series) silicified ostracode fauna from the Highland Border Dounans Limestone at Lime Craig Quarry, Aberfoyle, Central Scotland, represents the earliest record of this group of Crustacea from the British part of the early Palaeozoic ‘North American’ plate.V. ABSTRACT: Palaeontological age determinations for a variety of Highland Border rocks are presented. The data are based on the results of recent prospecting which has demonstrated that macro- and microfossils are present in a much greater range of Highland Border lithologies than previously realised. Data from other studies are also incorporated, as are modern taxonomie re-assessments of older palaeontological discoveries, in a comprehensive survey of Highland Border biostratigraphy. These accumulated data demonstrate that all fossiliferous Highland Border rocks so far discovered are of Ordovician age, with the exception of the Lower Cambrian Leny Limestone.VI. ABSTRACT: The Highland Border Complex consists of at least four rock assemblages: a serpentinite and possibly other ophiolitic rocks of Early or pre-Arenig age; a sequence of limestones and conglomerates of Early Arenig age; a succession of dark shales, cherts, quartz wackes, basic lavas and associated volcanogenic sediments of Llanvirn and ? earlier age; and an assemblage of limestones, breccias, conglomerates and arenites with subordinate shales of Caradoc or Ashgill age. At least three assemblages are divided by unconformities and in theirmost general aspect have similarities with coeval rocks in western Ireland.The Highland Border Complex probably formed N of the Midland Valley arc massif in a marginal sea comparable with the Sunda shelf adjacent to Sumatra–Java. Strike-slip and thrust emplacement of the whole Complex in at least four episodes followed the probable generation of all or part of its rocks by pull-apart mechanisms.

scholarly journals Integrating paleontology, geothermometry, and sedimentology in determining the history of the Reelfoot Basin, southern midcontinent, U.S.A.

1992 ◽  
Vol 6 ◽  
pp. 243-243
Author(s):  
J.E. Repetski ◽  
M.E. Taylor ◽  
D.S. Collins ◽  
A.R. Palmer ◽  
G.D. Wood ◽  
...  
Keyword(s):  
Cold Water ◽  
Vitrinite Reflectance ◽  
Short Interval ◽  
Regional Scale ◽  
Recent Analysis ◽  
Seismic Zone ◽  
Eastern United States ◽  
Early Ordovician ◽  
Lower Ordovician ◽  
History Of

The northeast-trending Reelfoot basin, extending from northeast Arkansas and westernmost Tennessee into southeastern Missouri, southernmost Illinois, and westernmost Kentucky, is geologically, and socioeconomically, significant because it is co-extensive with the New Madrid Seismic Zone, one of the most seismically active areas of the central and eastern United States. The basin has been periodically active from its inception as a rift basin in the Proterozoic to the present and has accumulated up to at least 5,000 m of sediment, including up to at least 1 km of Cretaceous and Tertiary sedimentary strata near the head of the Mississippi Embayment. Structural and stratigraphic interpretations within the subsurface pre-Mesozoic part of the basin have been based almost entirely on geophysical and physical stratigraphic criteria; these interpretations have been loosely constrained due to an extreme sparsity of drillhole data through the Paleozoic sequence. Recent analysis of Cambrian and Ordovician fossils (conodonts, palynomorphs, brachiopods, and trilobites) from cuttings and core from a very few drillholes allows establishment of the beginnings of a verifiable stratigraphy for this part of the sequence. The paleontological data also provide (1) biofacies evidence for interpretations of the depositional setting during part of the Late Cambrian and Early Ordovician interval and (2) thermal maturation data pertaining to the post-depositional geothermal history of these strata.Upper Cambrian phosphatic brachiopods and trilobites provide improved correlations between strata in the basin, the Ozark shelf to the northwest, and the Upper Mississippi River Valley. Cold-water-realm palynomorphs and trilobites from siliciclastic rocks of turbiditic origin in the central part of the Reelfoot basin support an interpretation, based on sedimentary structures in a short interval of core, of a deep-water basinal origin for these strata.Lower Ordovician conodonts provide a biostratigraphy for the carbonate rocks of this part of the sequence; correlations can be made with the shallow-water sequences of the Knox, Prairie du Chien, and Arbuckle Groups, and the Ozark sequence of the adjacent shelf areas to the east, north, and west. The uppermost Lower Ordovician strata in the basin record a short-term incursion of cooler water environments, reflected by the character of both the conodont fauna and the lithofacies. The youngest Paleozoic dates known from the basin south of the Pascola arch are latest Ibexian (Early Ordovician).Thermal alteration indices of both the Cambrian palynomorphs (organic-walled microphytoplankton) and Ordovician conodonts in the deeper parts of the basin, corroborated by fluid inclusion thermometry, vitrinite reflectance, and other geochemical techniques, are of higher values than predicted using any published estimates of overburden burial. These maturation values most likely reflect burial enhanced by the passage of hydrothermal fluids on a regional scale; they place constraints on interpretations of the tectonothermal evolution of the basin.

scholarly journals Cenozoic tectonic history of the North America-Caribbean plate boundary zone in western Cuba

1997 ◽  
Vol 102 (B5) ◽  
pp. 10055-10082 ◽  
Author(s):  
Mark B. Gordon ◽  
Paul Mann ◽  
Dámaso Cáceres ◽  
Raúl Flores
Keyword(s):  
North America ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Caribbean Plate ◽  
The North ◽  
Tectonic History ◽  
History Of ◽  
Plate Boundary Zone

Detrital zircon populations in quartzites of the Krkonoše–Jizera Massif: implications for pre-collisional history of the Saxothuringian Domain in the Bohemian Massif

2011 ◽  
Vol 149 (3) ◽  
pp. 443-458 ◽  
Author(s):  
ELIŠKA ŽÁČKOVÁ ◽  
JIŘÍ KONOPÁSEK ◽  
JAN KOŠLER ◽  
PETR JEŘÁBEK
Keyword(s):  
Detrital Zircon ◽  
Inductively Coupled Plasma ◽  
Detrital Zircons ◽  
Passive Margin ◽  
Inductively Coupled ◽  
Northwestern Margin ◽  
Plasma Mass Spectrometry ◽  
History Of ◽  
Early Palaeozoic ◽  
Ordovician Granitoids

AbstractAge spectra of detrital zircons from metamorphosed quartzites of the Krkonoše–Jizera Massif in the northeastern part of the Saxothuringian Domain were obtained by U–Pb laser ablation inductively coupled plasma mass spectrometry dating. The zircon ages cluster in the intervals of 450–530 Ma and 550–670 Ma, and show individual data between 1.6 and 3.1 Ga. Zircons in the analysed samples are predominantly of Cambrian–Ordovician and Neoproterozoic age, and the marked peak at c. 525–500 Ma suggests a late Cambrian maximum age for the sedimentary protolith. Detritus of the quartzites probably originated from the erosion of Cambrian–Ordovician granitoids and their Neoproterozoic (meta)sedimentary or magmatic country rocks. The lack of Neoproterozoic (meta)sedimentary rocks in the central and eastern part of the Krkonoše–Jizera Massif suggests that the country rocks to voluminous Cambrian–Ordovician magmatic bodies were largely eroded during the formation of early Palaeozoic rift basins along the southeast passive margin of the Saxothuringian Domain. The detrital zircon age spectra confirm the previous interpretation that the exposed basement, dominated by Neoproterozoic to Cambrian–Ordovician granitoids, was overthrust during Devonian–Carboniferous subduction–collision processes by nappes composed of metamorphosed equivalents of the uppermost Cambrian–Devonian passive margin sedimentary formations. Only a negligible number of Mesoproterozoic ages, typically from the Grenvillian event, supports the interpretation that the Saxothuringian Neoproterozoic basement has an affinity to the West African Craton of the northwestern margin of Gondwana.

STRUCTURAL ANALYSIS OF THE WICHITA UPLIFT AND STRUCTURES IN THE ANADARKO BASIN, SOUTHERN OKLAHOMA

2020 ◽  
pp. 1-51 ◽  
Author(s):  
Molly Turko ◽  
Shankar Mitra
Keyword(s):  
Normal Faults ◽  
Anadarko Basin ◽  
Tectonic History ◽  
Arbuckle Group ◽  
Southern Oklahoma ◽  
Northwestern Margin ◽  
History Of ◽  
Regional Stresses ◽  
Surface Geology ◽  
2D And 3D

We have constructed regional structural transects across the Wichita Uplift and adjacent Anadarko Basin to show the relationship between thick-skinned basement-involved structures and thin-skinned detached fold-thrust structures. Slip from the basement-involved structures in the Wichita Uplift is transferred along two major detachments into the Anadarko Basin. Our interpretation is that along the northwestern margin, the Wichita Uplift is marked by a zone of frontal imbricates forming a triangular wedge with most of the slip dissipated along the Wichita front. Paleozoic units show tight folding with overturned beds in the frontal zone. The uplift is episodic as indicated by the truncation of major faults along unconformities and their subsequent reactivation. In contrast, along the southeast margin, a significant part of the slip is transferred into structures in the Anadarko Basin. These structures are tight faulted-detachment folds that formed above a major detachment within the Springer Shale, cored by broader structures detaching at the base of the Arbuckle Group. Examples include the Carter-Knox, Cement-Chickasha, and Cruce structures. Oblique faults with normal and strike-slip components cut some of these structures, resulting in more complex geometries. We propose that pre-existing normal faults of Precambrian-Cambrian age were either reactivated along the Wichita Uplift, or controlled the location of the Pennsylvanian age structures in the Anadarko Basin. Progressive rotation of regional stresses from northeast-southwest to a more east-northeast-west-southwest direction during the Pennsylvanian impacted the tectonic history of the area. We used 2D and 3D seismic, well log data, and surface geology were used to evaluate the structural styles and tectonic evolution of the Wichita Uplift and the Anadarko Basin.

Neodymium isotopic composition of Cambrian–Ordovician biogenic apatite in the Baltoscandian Basin: implications for palaeogeographical evolution and patterns of biodiversity

2005 ◽  
Vol 142 (4) ◽  
pp. 419-439 ◽  
Author(s):  
ULF STURESSON ◽  
LEONID E. POPOV ◽  
LARS E. HOLMER ◽  
MICHAEL G. BASSETT ◽  
SERGEI FELITSYN ◽  
...  
Keyword(s):  
Sea Water ◽  
Constant Factor ◽  
Turnover Rates ◽  
Benthic Assemblages ◽  
The North ◽  
Tectonic History ◽  
Iapetus Ocean ◽  
History Of ◽  
Early Palaeozoic ◽  
T Values

Biogenic apatite preserved in 148 samples of conodonts and organophosphatic-shelled brachiopods from Cambrian through Ordovician successions of the Baltoscandian Basin (Baltica Plate) preserves a sensitive record of early Palaeozoic sea-water chemistry interpreted via neodymium isotope ratios. Consistent ${\uvarepsilon}$Nd(t) values of −9.6 to −8.3 for Lower to Middle Cambrian samples suggest no significant lateral or temporal variation across the region. Average Upper Cambrian values are −7.2 to −7.7. Sedimentary analysis suggests that the influence of continental weathering from Baltica as a major source of radiogenic Nd was negligible. Ordovician samples show a rise to −5 to −6 in the early Arenig, early–mid Llanvirn and late Caradoc. Sea-water mixing from the southeast Iapetus Ocean was a constant factor throughout Cambrian–Ordovician times. The rise reflects erosion of obducted volcanic arc complexes along the Caledonian margin, and probably also relates to pollution of the Baltica sector of Iapetus from the approaching Avalonia Plate. Patterns of evolutionary biodiversity and palaeobiogeographical linkages support the geochemical signatures in interpreting the tectonic history of the region. Extinction of lingulate brachiopod faunas in the Tremadoc, followed by subsequent recovery and emergence of benthic assemblages typical of the Ordovician Evolutionary Fauna in the Billingen–early Volkhov regional stages coincide with significant changes in geochemical characteristics of water masses across the Baltoscandian basin. The early and mid Ordovician (Arenig to Llandeilo) brachiopod faunas of the North Estonian Confacies Belt are characterized by high endemism and low turnover rates, whereas increased immigration resulted in the extinction of a number of local lineages in the late Llanvirn. From the mid Caradoc to mid Ashgill, when Baltica was drifting on a course to collide eventually with Avalonia and gradually approach Laurentia, brachiopod assemblages were characterized by higher turnover rates. At the same time they gradually became more cosmopolitan and less influenced by the invasion of new faunas.

Microscopic and megascopic fabrics in the Skiddaw Group, Black Combe inlier, English Lake District

1969 ◽  
Vol 106 (6) ◽  
pp. 587-594 ◽  
Author(s):  
Douglas G. Helm
Keyword(s):  
Clay Minerals ◽  
Regional Metamorphism ◽  
Axial Plane ◽  
Low Grade ◽  
Lake District ◽  
Tectonic History ◽  
Lower Ordovician ◽  
English Lake District ◽  
History Of

SUMMARYThe rocks of the Skiddaw Group of the Black Combe inlier were subjected to low grade regional metamorphism during the D1 movementphase of an intra-Lower Ordovician orogenic episode. Mimetic recrystallisation of clay minerals parallel to the bedding was ubiquitous. Later, axial-plane cleavages were superimposed on this fabric. The nature of the cleavages and possible mechanism of their formation is discussed.Silica has been mobilised on at least three occasions during the tectonic history of the inlier. In no case was this due to metasomatism but simply to metamorphic differentiation. The D1 veins are of either quartz, or quartz and chlorite whereas veins of later generations are of quartz alone.

Lower Ordovician brachiopods from the Ben Suardal Limestone Formation (Durness Group) of Skye, western Scotland

1984 ◽  
Vol 75 (3) ◽  
pp. 301-310 ◽  
Author(s):  
Gordon B. Curry ◽  
Alwyn Williams
Keyword(s):  
New Species ◽  
Plate Tectonic ◽  
Iapetus Ocean ◽  
Lower Ordovician ◽  
Northwestern Margin ◽  
Tectonic Position ◽  
Early Palaeozoic ◽  
Isle Of Skye

ABSTRACTTen silicified brachiopod taxa have been recovered from the Ben Suardal Limestone Formation (Durness Group) on the Isle of Skye, western Scotland. This Arenig fauna contains a new camerellid genus, Boreadocamara, and new species of each of the orthacean genera Archaeorthis, Fasciculina, and Oligorthis. Representatives of Billingsella, Finkelnburgia, Syntrophia, Syntrophopsis, and an indeterminate orthacean have also been recovered from etched residues of the Ben Suardal Limestone. The Skye fossils show strong affinities with the Scoto-Appalachian or American faunal province, in keeping with the inferred plate tectonic position of the Durness Group along the northwestern margin of the early Palaeozoic ‘Iapetus’ Ocean.

Evidence for a Caledonian orogeny in Poland

1994 ◽  
Vol 85 (2) ◽  
pp. 131-142 ◽  
Author(s):  
J. D. Johnston ◽  
J. A. Tait ◽  
G. J. H. Oliver ◽  
F. C. Murphy
Keyword(s):  
Central And Eastern Europe ◽  
The Czech Republic ◽  
Middle Ordovician ◽  
Continental Scale ◽  
Holy Cross Mountains ◽  
Tectonic History ◽  
Iapetus Ocean ◽  
Lower Ordovician ◽  
History Of ◽  
Lower Palaeozoic

AbstractThe Lower Palaeozoic tectonic history of central and eastern Europe is poorly understood because of extensive Variscan and/or Alpine reworking. The trace of the Tornquist Sea, the SE arm of the Lower Palaeozoic Iapetus Ocean, extended from NE Britain to Asia Minor. The site of this ocean is constrained by the tectonostratigraphy and faunal provinciality of Lower Palaeozoic inliers in northern Czechoslovakia, and southern Poland. In this paper, the collage of contrasting tectonostratigraphic histories of terranes in the Lower Palaeozoic of Poland is reviewed. Fossil evidence demonstrates that the Holy Cross Mountains and the Krakovian Belt display Lower Ordovician and Lower Devonian angular unconformities. Faunal data suggest that the Tornquist Suture Zone must lie south of the Holy Cross and between Upper Silesia and the Barrandian of the Czech Republic. Between these areas, in the Sudeten Mountains, a continental scale sinistral mylonite zone (along the line of the Intra-Sudetic Fault) was periodically active between the Middle Ordovician and the Upper Triassic. Various dismembered ophiolite, island arc and batholith terranes from alongside the Intra-Sudetic Fault have Ordocivian and Silurian magmatic and metamorphic zircon isotopic and fossil ages. Thus the often stated view that deformation in the Sudetes is Variscan (i.e. post-Middle Devonian) must be called into question. It is proposed instead that the Tornquist Suture is located within the Sudeten mountains, and as in the Holy Cross Mountains, much of the observed deformation is post-Cambrian and pre-Gedinnian in age, i.e. Caledonian.

Tectonic history of the Dent Blanche

2017 ◽  
Vol 9 (2.1) ◽  
pp. 1-73 ◽  
Author(s):  
Paola Manzotti ◽  
Michel Ballèvrei
Keyword(s):  
Tectonic History ◽  
History Of
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