scholarly journals Part 5. Plate boundary evolution in the New Guinea region: Volcanic and plate tectonic evolution of central Papua New Guinea

1975 ◽  
Vol 6 (2-3) ◽  
pp. 66-68 ◽  
Author(s):  
D.E. Mackenzie
2016 ◽  
Vol 2 (7) ◽  
pp. e1600022 ◽  
Author(s):  
Lydian M. Boschman ◽  
Douwe J. J. van Hinsbergen

The oceanic Pacific Plate started forming in Early Jurassic time within the vast Panthalassa Ocean that surrounded the supercontinent Pangea, and contains the oldest lithosphere that can directly constrain the geodynamic history of the circum-Pangean Earth. We show that the geometry of the oldest marine magnetic anomalies of the Pacific Plate attests to a unique plate kinematic event that sparked the plate’s birth at virtually a point location, surrounded by the Izanagi, Farallon, and Phoenix Plates. We reconstruct the unstable triple junction that caused the plate reorganization, which led to the birth of the Pacific Plate, and present a model of the plate tectonic configuration that preconditioned this event. We show that a stable but migrating triple junction involving the gradual cessation of intraoceanic Panthalassa subduction culminated in the formation of an unstable transform-transform-transform triple junction. The consequent plate boundary reorganization resulted in the formation of a stable triangular three-ridge system from which the nascent Pacific Plate expanded. We link the birth of the Pacific Plate to the regional termination of intra-Panthalassa subduction. Remnants thereof have been identified in the deep lower mantle of which the locations may provide paleolongitudinal control on the absolute location of the early Pacific Plate. Our results constitute an essential step in unraveling the plate tectonic evolution of “Thalassa Incognita” that comprises the comprehensive Panthalassa Ocean surrounding Pangea.


1989 ◽  
Vol 162 (3-4) ◽  
pp. 291-302 ◽  
Author(s):  
Andrew B. Cullen ◽  
John D. Pigott

Tectonics ◽  
1993 ◽  
Vol 12 (3) ◽  
pp. 611-628 ◽  
Author(s):  
Suzanne L. Baldwin ◽  
Gordon S. Lister ◽  
E. June Hill ◽  
David A. Foster ◽  
Ian McDougall

1978 ◽  
Vol 73 (5) ◽  
pp. 810-828 ◽  
Author(s):  
S. R. Titley ◽  
A. W. Fleming ◽  
T. I. Neale

2021 ◽  
Vol 9 ◽  
Author(s):  
Lei Sun ◽  
Paul Mann

The area of southeastern Papua New Guinea includes three active microplates – the Trobriand, Woodlark, and Solomon Sea plates – that are being deformed by regional convergence between the much larger Pacific and Australian Plates. The landward extent of the plate boundary between the Trobriand and Australian Plates corresponds to the Owen-Stanley Fault Zone (OSFZ), an onland and continuous 510 km-long left-lateral strike-slip fault that forms a linear, intermontane valley within the elongate Owen-Stanley Range (OSR) and continues as a 250 km-long low-angle normal fault along the margins of Goodenough and Woodlark basins. GPS geodesy reveals that the Trobriand microplate has undergone rapid counter-clockwise rotation since the Late Miocene (8.4 Ma) and that this rotation about a nearby pole of rotation predicts transpressional deformation along the 250 km-long northwestern segment of the OSFZ, strike-slip motion along a 100 km-long central segment, and transtension along the 270 km-long ESE-trending southeastern segment of OSFZ. In order to illustrate the along-strike variations in neotectonic uplift resulting from the changing structure of the OSFZ, we delineated 3903 river segments in the northeastern side of the OSR drainage divide and derived river longitudinal profiles along each river segment. Normalized steepness indices (ksn) and knickpoint clusters are the highest and most concentrated, respectively, for the northwestern transpressional segment of the OSR, moderately high and concentrated along the southeastern segment of the OSR, and the lowest and least concentrated along the central strike-slip segment. These geomorphological indices indicate that most of the plate boundary uplift occurs along the transpressional and transtensional segments that are connected by the central strike-slip zone. Within this overall pattern of structural variation, abrupt changes in the azimuth of the OSFZ create more localized anomalies in the geomorphological indices.


1975 ◽  
Vol 6 (3) ◽  
pp. 77
Author(s):  
R.J.S. Cooke

A striking spatial and temporal clustering of volcanic eruptions has occurred in the Bismarck Volcanic Arc, Papua New Guinea, since late 1972. In the complete arc, six volcanoes have been active during this period, Long Island, Langila, Ulawan, Karkar, Manam, and Ritter Island. Ulawan is located in the eastern (New Britain) half of the arc. The other five are located consecutively in the western half of the arc; no definite historical eruptions are known from any other volcano in the sector containing them. This western half is distinguishable from the eastern half on petrological and geophysical grounds by Johnson (this Symposium). The only western volcanoes with historical eruptions but not active in this present phase, are in the Schouten Islands at the far western end of the arc; this sector is also petrologically distinguishable.


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