STRUCTURAL FRAMEWORK AND BASIN EVOLUTION OF AUSTRALIA’S SOUTHERN MARGIN

2003 ◽  
Vol 43 (1) ◽  
pp. 13 ◽  
Author(s):  
J.P. Teasdale ◽  
L.L. Pryer ◽  
P.G. Stuart-Smith ◽  
K.K. Romine ◽  
M.A. Etheridge ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Structural Control ◽  
Structural Evolution ◽  
Shear Zones ◽  
Basin Evolution ◽  
Primary Control ◽  
Fold Belt ◽  
Southern Margin ◽  
Lachlan Fold Belt ◽  
Basement Structures

The structural evolution of all of the Southern Margin Basins can be explained by episodic reactivation of basement structures in respect to a specific sequence of tectonic events. Three geological provinces dominate the basement geology of the Southern Margin basins. The Eyre, Ceduna, Duntroon and Polda Basins overlie basement of the Archean to Proterozoic Gawler-Antarctic Craton. The Otway and Sorell Basins overlie basement of the Neoproterozoic-early Palaeozoic Adelaide- Kanmantoo Fold Belt. The Bass and Gippsland Basins overlie basement of the Palaeozoic Lachlan Fold Belt. The contrasting basement terranes within the three basement provinces and the structures within and between them significantly influenced the evolution and architecture of the Southern Margin basins.The present-day geometry was established during three Mesozoic extensional basin phases:Late Jurassic–Early Cretaceous NW–SE transtension forming deep rift basins to the west and linked pullapart basins and oblique graben east of the Southwest Ceduna Accommodation Zone; Early–Mid Cretaceous NE–SW extension; and Late Cretaceous NNE–SSW extension leading to continental breakup. At least three, potentially trap forming, inversion events have variably influenced the Southern Margin basins; Mid Cretaceous, Eocene, and Miocene-Recent. Volcanism occurred along the margin during the Late Cretaceous and sporadically through the Tertiary.First-order structural control on Mesozoic rifting and breakup were east–west trending basement structures of the southern Australian fracture zone. Second-order controls include:Proterozoic basement shear zones and/or terrane boundaries in the western Gawler Craton, which controlled basin evolution in the Eyre and Ceduna Subbasins; Neoproterozoic structures, which significantly influenced basin evolution in the Ceduna sub-basin; Cambro-Ordovician basement shear zones and/or terrane boundaries, which were a primary control on basin evolution in the Otway and Sorell Basins; and Palaeozoic structures in the Lachlan Fold Belt, which controlled basin evolution in the Bass and Gippsland Basins.A SEEBASE™ (Structurally Enhanced view of Economic Basement) model for the Southern Margin basins has been constructed to show basement topography. When used in combination with a rigorous interpretation of the structural evolution of the margin, it provides a foundation for basin phase and source rock distribution, hydrocarbon fluid focal points and trap type/distribution.

scholarly journals Structural analysis of the Rio Preto fold belt (northwestern Bahia / southern Piauí), a doubly-vergent asymmetric fan developed during the Brasiliano Orogeny

2014 ◽  
Vol 86 (3) ◽  
pp. 1101-1113 ◽  
Author(s):  
FABRÍCIO A. CAXITO ◽  
ALEXANDRE UHLEIN ◽  
LUIZ F.G. MORALES ◽  
MARCOS EGYDIO-SILVA ◽  
JULIO C.D. SANGLARD ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Structural Evolution ◽  
Shear Zones ◽  
Central Compartment ◽  
Strike Slip ◽  
Fold Belt ◽  
Main Structure ◽  
The North ◽  
Brasiliano Orogeny ◽  
Analog Models

The Rio Preto fold belt borders the northwestern São Francisco craton and shows an exquisite kilometric doubly-vergent asymmetric fan structure, of polyphasic structural evolution attributed exclusively to the Brasiliano Orogeny (∼600-540 Ma). The fold belt can be subdivided into three structural compartments: The Northern and Southern compartments showing a general NE-SW trend, separated by the Central Compartment which shows a roughly E-W trend. The change of dip of S2, a tight crenulation foliation which is the main structure of the fold belt, between the three compartments, characterizes the fan structure. The Central Compartment is characterized by sub-vertical mylonitic quartzites, which materialize a system of low-T strike slip shear zones (Malhadinha – Rio Preto Shear Zone) crosscutting the central portion of the fold belt. In comparison to published analog models, we consider that the unique structure of the Rio Preto fold belt was generated by the oblique, dextral-sense interaction between the Cristalândia do Piauí block to the north and the São Francisco craton to the south.

GEOLOGIC EVOLUTION AND HYDROCARBON HABITAT GIPPSLAND BASIN

1972 ◽  
Vol 12 (1) ◽  
pp. 132 ◽  
Author(s):  
J. Barry Hocking
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Meteoric Water ◽  
Oil And Gas ◽  
Basin Evolution ◽  
Fold Belt ◽  
Apparent Lack ◽  
Northern Flank ◽  
Southeastern Australia ◽  
Gippsland Basin

The Gippsland Basin of southeastern Australia is a post-orogenic, continental margin type of basin of Upper Cretaceous-Cainozoic age.Gippsland Basin evolution can be traced back to the establishment of the Strzelecki Basin, or ancestral Gippsland Basin, during the Jurassic. Gippsland Basin sedimentation commenced in the middle to late Cretaceous and is represented as a gross transgressive-regressive cycle consisting of the continental Latrobe Valley Group (Upper Cretaceous to Eocene or Miocene), the marine Seaspray Group (Oligocene to Pliocene or Recent), and finally the continental Sale Group (Pliocene to Recent).The hydrocarbons of the Gippsland Shelf petroleum province were generated within the Latrobe Valley Group and are trapped in porous fluvio-deltaic sandstones of the Latrobe. At Lakes Entrance, however, oil and gas are present in a marginal sandy facies of the Lakes Entrance Formation (Seaspray Group).The buried Strzelecki Basin has played a fundamental role in the development and distribution of the Cainozoic fold belt in the northern Gippsland Basin. The Gippsland Shelf hydrocarbon accumulations fall within this belt and are primarily structural traps. The apparent lack of structural accumulations onshore in Gippsland is largely due to a Plio-Pleistocene episode of cratonic uplift that was accompanied by basinward tilting of structures and meteoric water influx.The non-commercial Lakes Entrance field, located on the stable northern flank of the basin, is a stratigraphic trap and may serve as a guide for future exploration.

Alleghanian reactivation of the Acadian fold belt, Meguma Zone, southwest Nova Scotia

1997 ◽  
Vol 34 (6) ◽  
pp. 833-847 ◽  
Author(s):  
Nicholas Culshaw ◽  
Montserrat Liesa
Keyword(s):  
Nova Scotia ◽  
Shear Zones ◽  
Fold Belt ◽  
Geochronological Data ◽  
Basement Structures

Shear zones and northwest-verging folds define a 30 km wide belt of deformation that overprints the Acadian fold belt and telescopes isograds in the Meguma Zone in southwest Nova Scotia. The shear zones appear to form a linked system that accommodated convergence-dominated transpression of the Meguma Zone against an irregular Avalon boundary. Available geochronological data indicate a Mid-Carboniferous (Alleghanian–Variscan) age for the overprinting deformation. The Mid-Carboniferous basement reactivation in southwest Nova Scotia is likely coeval with deformation of Carboniferous strata and reactivation of basement structures (Meguma Group) in the northern Meguma Zone. Together, these Mid-Carboniferous structures may define a wide belt of Alleghanian–Variscan deformation across the northwest (cratonward) margin of the Meguma Zone.

scholarly journals ΤΗE PELAGONIAN NAPPE PILE IN NORTHERN GREECE AND FYROM. STRUCTURAL EVOLUTION DURING THE ALPINE OROGENY: A NEW APROACH

2017 ◽  
Vol 43 (1) ◽  
pp. 276 ◽  
Author(s):  
Ad. Kilias ◽  
W. Frisch ◽  
A. Avgerinas ◽  
I. Dunkl ◽  
G. Falalakis ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Late Jurassic ◽  
Structural Evolution ◽  
Shear Zones ◽  
Low Grade ◽  
Northern Greece ◽  
Alpine Orogeny ◽  
Clastic Sediments ◽  
History Of ◽  
Structural Levels

The geometry of kinematics and the deformation history of the Pelagonian nappe pile during the Alpine orogeny have been studied in Northern Greece and FYROM. Deformation was started in Middle-Late Jurassic time and was initially associated with ocean-floor subduction followed by ophiolites obduction, nappe stacking and duplication of the Pelagonian continent. The footwall Pelagonian segment from top to bottom was metamorphosed under greenschist to amphibolit facies conditions and a relative high pressure (T = 450o to 620o C and P = 12,5 to 8 kb). Blueschist facies metamorphic assemblages of Late Jurassic age are immediately developed between both hangingwall and footwall Pelagonian segments. Transgressive Late Jurassic-Early Cretaceous neritic limestones and clastic sediments on the top of the obducted ophiolites are maybe related to extension and basins formation simultaneously with the nappe stacking and metamorphism at the lower structural levels of the Pelagonian nappes. Contractional tectonics and nappe stacking continued during the Albian-Aptian time. Simultaneously retrogression and pressure decreasing taken place at the tectonic lower Pelagonian footwall segment. Low grade mylonitic shear zones, possible related to extension, are developed during Late Cretaceous time simultaneously with basins formation and sedimentation of neritic Late Cretaceous to Paleocene limestones and flysch. Intense shortening and imbrication under semi-ductile to brittle conditions occurred during Paleocene to Eocene time resulting the onset of the dome like formation of the footwall Pelagonian segment. The next stages of deformation from Oligocene to Quaternary are related to brittle extension and the final uplift and configuration of the Pelagonian nappe pile.

scholarly journals Evidence for hybridisation in the Tynong Province granitoids, Lachlan Fold Belt, eastern Australia

2016 ◽  
Vol 63 (3) ◽  
pp. 235-255 ◽  
Author(s):  
K. R. Regmi ◽  
R. F. Weinberg ◽  
I. A. Nicholls ◽  
R. Maas ◽  
M. Raveggi
Keyword(s):  
Fold Belt ◽  
Eastern Australia ◽  
Lachlan Fold Belt

A structural reappraisal of the Beardmore–Geraldton Belt at the southern boundary of the Wabigoon subprovince, Ontario, and implications for gold mineralization

2004 ◽  
Vol 41 (2) ◽  
pp. 217-235 ◽  
Author(s):  
Bruno Lafrance ◽  
Jerry C DeWolfe ◽  
Greg M Stott
Keyword(s):  
Gold Mineralization ◽  
Shear Zones ◽  
Axial Plane ◽  
Superior Province ◽  
Southern Boundary ◽  
Gold Mines ◽  
Southern Margin ◽  
Ore Zones

The Beardmore–Geraldton Belt occurs along the southern margin of the Archean Wabigoon subprovince, Superior Province, Ontario. The belt consists of shear-bounded interleaved metasedimentary and metavolcanic units. The units were imbricated from 2696 to 2691 Ma during D1 thrusting and accretion of the Wabigoon, Quetico, and Wawa subprovinces. Post-accretion D2 deformation produced regional F2 folds that transposed lithological units parallel to the axial plane S2 cleavage of the folds. During D3 deformation, the folds were overprinted by a regional S3 cleavage oriented anticlockwise of F2 axial planes, and lithological contacts and S2 cleavage were reactivated as planes of shear within dextral regional shear zones that generally conform to the trend of the belt. D3 is a regional dextral transpression event that also affected the Quetico and Wawa subprovinces, south of the Beardmore–Geraldton Belt. Gold mineralization at the Leitch and MacLeod-Cockshutt mines, the two richest past-producing gold mines in the Beardmore–Geraldton Belt, is associated with D3 shear zones and folds, overprinting regional F2 folds. The plunge of the ore zones is parallel to F3 fold axes and to the intersection of D3 shear zones with F2 and F3 folds.

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