Cretaceous to present-day tectonic reconstructions of Zealandia

2018 ◽  
Vol 58 (2) ◽  
pp. 852
Author(s):  
Hannu Seebeck ◽  
Dominic Strogen ◽  
Peter King ◽  
Andrew Nicol ◽  
Ben Hines ◽  
...  
Keyword(s):  
Plate Boundary ◽  
Sedimentary Basins ◽  
Time Intervals ◽  
Plate Motions ◽  
The Past ◽  
Plate Reconstructions ◽  
Tectonic Framework ◽  
Tectonic Reconstructions ◽  
Plate Boundary Zone ◽  
Geological Constraints

Reconstructions of the past relative positions of northern and southern Zealandia provide important constraints on the orientation and amount of strain accumulated between rigid plates within the Australia–Pacific plate tectonic circuit. This configuration of plates ultimately determines how, where and when sedimentary basins formed during and since continental breakup along the eastern margin of Gondwana. Although the first-order geometry of Zealandia is well established, uncertainty remains regarding plate motions through the latest Cretaceous to Eocene. Recent reconstructions are, in some cases, inconsistent with geological observations at key time intervals, highlighting uncertainties inherent in plate reconstructions for the south-west Pacific. Building on previous tectonic reconstructions and incorporating published seafloor magnetic interpretations, paleomagnetic observations and geological constraints (e.g. terrane geometry and distribution), we developed a tectonic framework to reconstruct Zealandia back through to the latest Cretaceous. Using GPlates, we use a simple double-hinge slat concept to describe Neogene deformation within the New Zealand plate boundary zone, while the geometry of northern and southern Zealandia during the Eocene is modified from recently published models based on geologic considerations. This study ultimately highlights the need for integrated studies of the Zealandia plate circuit.

scholarly journals Phanerozoic reconstructions: What and how do we know it

1992 ◽  
Vol 6 ◽  
pp. 253-253
Author(s):  
David B. Rowley
Keyword(s):  
Late Jurassic ◽  
State Of The Art ◽  
Polar Wander ◽  
Plate Motions ◽  
Computer Animations ◽  
The Past ◽  
Data Comparison ◽  
Plate Reconstructions ◽  
Using Data ◽  
Present Understanding

Paleobiogeography will play an important role in furthering our understanding of global change, particularly with respect to providing constraints on past climates. As a result of this there is increasing emphasis within the paleontological community on the past spatial distributions of faunas, extinctions, and originations. Thus there is an increasing interest in reconstructions of the past distributions of continents, so that maps and paleo-latitudes of faunas, extinctions or originations can be determined. This results in an increasing need to understand the state of the art of global plate reconstructions through the Mesozoic and Cenozoic, and global continental reconstructions through the Paleozoic, i.e. what we know and how well do we know it. The talk will summarize our present understanding of Mesozoic and Cenozoic plate motions using computer animations followed by a brief summary of the present understanding of individual continental apparent polar wander paths (APWP's) as well as motions in the global frame. Global and continental mean poles at approximately 20 Ma intervals have been computed for all of the major continents of the Phanerozoic using data from Van der Voo (1992) and plate motions derived from a detailed analysis of Mesozoic and Cenozoic seafloor spreading data. Comparison of mean continental poles reconstructed into the same reference frame shows that although there is general agreement, statistically different pole positions are quite commonly observed. This is particularly true for the Late Cretaceous and pre-Late Jurassic of the northern Hemisphere, and has resulted in some controversy concerning appropriate Atlantic fits. The differences in predicted (or reconstructed) paleo-latitudes are not trivial, particularly for areas of esatern Gondwanaland such as Australia and New Zealand, and are not easily visualized from a simple comparison of mean pole positions. A final focus will be with regards to reconstructions of Asia. Comparison of recently published Permian global reconstructions in the McKerrow and Scotese (1989) volume demonstrates that vast differences of interpretation persist and that paleontologists among others cannot accept exisiting reconstructions uncritically.

Duration of Time in Time-Related Words

1969 ◽  
Vol 29 (3) ◽  
pp. 775-781
Author(s):  
Martin S. Lindauer
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Time Perspective ◽  
Time Intervals ◽  
The Past

275 time-related words, considered a source for the cognitive investigation of time perspective, were assigned to 10 time intervals ranging from seconds to millennia by 32 Ss equally divided by sex. Differences were found in the duration of time connoted by the verbal materials, with reference to the frequency with which the 10 time intervals were used, as well as the time spans associated with the past, present, and future. No sex difference was noted.

scholarly journals Distribution of the Pacific/North America motion in the Queen Charlotte Islands-S. Alaska plate boundary zone

2003 ◽  
Vol 30 (14) ◽  
Author(s):  
Stéphane Mazzotti ◽  
Roy D. Hyndman ◽  
Paul Flück ◽  
Alex J. Smith ◽  
Michael Schmidt
Keyword(s):  
North America ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Queen Charlotte Islands ◽  
The Pacific ◽  
Plate Boundary Zone

Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic

1987 ◽  
Vol 321 (1557) ◽  
pp. 163-181 ◽  
Keyword(s):  
New Zealand ◽  
Subduction Zone ◽  
East Coast ◽  
Late Quaternary ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Metamorphic Belt ◽  
Volcanic Region ◽  
The North ◽  
Plate Boundary Zone

The subduction zone under the east coast of the North Island of New Zealand comprises, from east to west, a frontal wedge, a fore-arc basin, uplifted basement forming the arc and the Central Volcanic Region. Reconstructions of the plate boundary zone for the Cainozoic from seafloor spreading data require the fore-arc basin to have rotated through 60° in the last 20 Ma which is confirmed by palaeomagnetic declination studies. Estimates of shear strain from geodetic data show that the fore-arc basin is rotating today and that it is under extension in the direction normal to the trend of the plate boundary zone. The extension is apparently achieved by normal faulting. Estimates of the amount of sediments accreted to the subduction zone exceed the volume of the frontal wedge: underplating by the excess sediments is suggested to be the cause of late Quaternary uplift of the fore-arc basin. Low-temperature—high-pressure metamorphism may therefore be occurring at depth on the east coast and high-temperature—low-pressure metamorphism is probable in the Central Volcanic Region. The North Island of New Zealand is therefore a likely setting for a paired metamorphic belt in the making.

scholarly journals Overview of Cordilleran oceanic terranes and their significance for the tectonic evolution of the northern Cordillera

2021 ◽  
Author(s):  
A Zagorevski ◽  
C R van Staal ◽  
J H Bédard ◽  
A Bogatu ◽  
D Canil ◽  
...  
Keyword(s):  
Continental Margin ◽  
Tectonic Evolution ◽  
Middle Triassic ◽  
Passive Margin ◽  
Suprasubduction Zone ◽  
Ophiolitic Rocks ◽  
Juvenile Crust ◽  
Tectonic Framework ◽  
Tectonic Reconstructions ◽  
Stratigraphic Nomenclature

Ophiolite complexes are an important component of oceanic terranes in the northern Cordillera and constitute a significant amount of juvenile crust added to the Mesozoic Laurentian continental margin during Cordilleran orogenesis. Despite their tectonic importance, few systematic studies of these complexes have been conducted. Detailed studies of the pseudostratigraphy, age, geochemistry, and structural setting of ophiolitic rocks in the northern Cordillera indicate that ophiolites formed in Permian to Middle Triassic suprasubduction zone settings and were obducted onto passive margin sequences. Re-evaluation of ophiolite complexes highlights fundamental gaps in the understanding of the tectonic framework of the northern Cordillera. The previous inclusion of ophiolite complexes into generic 'oceanic' terranes resulted in significant challenges for stratigraphic nomenclature, led to incorrect terrane definitions, and resulted in flawed tectonic reconstructions.

scholarly journals Evidence for the Transfer of Corpuscles to Distant Parts of the Sun Following a Solar Radio Burst

1961 ◽  
Vol 14 (4) ◽  
pp. 540 ◽  
Author(s):  
RF Mullaly
Keyword(s):  
Radio Burst ◽  
Solar Radio ◽  
Brightness Distribution ◽  
Solar Radio Burst ◽  
The Sun ◽  
Time Intervals ◽  
The Past ◽  
Grating Interferometer ◽  
Half Power ◽  
East West

The brightness distribution of 21-cm radiation over the Sun's surface has been studied for the past four years with the Christiansen crossed-grating interferometer (Christiansen et al. 1961) at Fleurs near Sydney. The observations described here were made using one arm of this cross as a simple grating interferometer, providing a transit instrument with a fan beam of about 2' of arc resolution to half-power points in the east-west direction and very low resolution north-south. The Sun was scanned repeatedly from east to west at time intervals of approximately 4 min.

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