Fission-track dating of the tectonic development of the San Juan Islands, Washington

1986 ◽  
Vol 23 (9) ◽  
pp. 1318-1330 ◽  
Author(s):  
Samuel Y. Johnson ◽  
Robert A. Zimmermann ◽  
Charles W. Naeser ◽  
John T. Whetten
Keyword(s):  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Fission Track ◽  
Frictional Heating ◽  
Geothermal Gradient ◽  
Upper Triassic ◽  
Detrital Zircons ◽  
San Juan ◽  
San Juan Islands ◽  
Zircon Fission Track

The San Juan Islands of Washington State form a geologically complex province located between the north Cascades, Vancouver Island, and the Olympic Peninsula. We have obtained 53 fission-track dates from the San Juan Islands province that help constrain its late Paleozoic to early Cenozoic tectonic and sedimentary history and its relationship to neighboring geologic terranes. The San Juan Islands can be divided into two main blocks separated by the Haro fault. South of the Haro fault, complexly deformed, metamorphosed, and probably exotic early Paleozoic to early Late Cretaceous rocks form four imbricate thrust plates separated by south- and east-dipping late Early to Late Cretaceous thrust faults. Reset zircon fission-track dates indicate that thrusting may have produced an upside-down geothermal gradient in the uppermost plate, the Decatur terrane. If present, this gradient was probably produced by conductive or frictional heating associated with a now-eroded overlying thrust fault and hot thrust plate. Cretaceous thrusting in the southern San Juan Islands was accompanied by uplift and resetting of apatite fission-track dates. In contrast to correlative rocks of the southern San Juan Islands, Upper Triassic to Lower Cretaceous rocks in and north of the Haro fault zone are essentially unmetamorphosed and only broadly folded. Apatite dates from the Upper Triassic Haro Formation and the Upper Jurassic and Lower Cretaceous Spieden Group indicate they did not participate in Late Cretaceous uplift of the southern San Juan Islands. Together with their basement (the Wrangellia terrane?), these rocks probably acted as a backstop to thrusting. The synorogenic Late Cretaceous Nanaimo basin formed north of the Haro fault in front of the advancing San Juan Islands thrust system. The age of Nanaimo deposition matches uplift (apatite) dates in the southern San Juan Islands, and detrital zircons from the Nanaimo Group yield dates consistent with southern San Juan Islands sources. Burial led to resetting of apatite dates in what is probably the deeper part of the Nanaimo basin.

Obducted nappe sequence in the San Juan Islands – northwest Cascades thrust system, Washington and British Columbia

2012 ◽  
Vol 49 (7) ◽  
pp. 796-817 ◽  
Author(s):  
E.H. Brown
Keyword(s):  
British Columbia ◽  
Detrital Zircons ◽  
San Juan ◽  
San Juan Islands ◽  
Tectonic History ◽  
Plutonic Complex ◽  
Coast Plutonic Complex ◽  
History Of ◽  
Accreted Terranes ◽  
Thrust System

The San Juan Islands – northwest Cascades thrust system in Washington and British Columbia is composed of previously accreted terranes now assembled as four broadly defined composite nappes stacked on a continental footwall of Wrangellia and the Coast Plutonic Complex. Emplacement ages of the nappe sequence are interpreted from zircon ages, field relations, and lithlogies, to young upward. The basal nappe was emplaced prior to early Turonian time (∼93 Ma), indicated by the occurrence of age-distinctive zircons from this nappe in the Sidney Island Formation of the Nanaimo Group. The emplacement age of the highest nappe in the thrust system postdates 87 Ma detrital zircons within the nappe. The nappes bear high-pressure – low-temperature (HP–LT) mineral assemblages indicative of deep burial in a thrust wedge; however, several features indicate that metamorphism occurred prior to nappe assembly: metamorphic discontinuities at nappe boundaries, absence of HP–LT assemblages in the footwall to the nappe pile, and absence of significant unroofing detritus in the Nanaimo Group. A synorogenic relationship of the thrust system to the Nanaimo Group is evident from mutually overlapping ages and by conglomerates of Nanaimo affinity that lie within the nappe pile. From the foregoing relations, and broader Cordilleran geology, the tectonic history of the nappe terranes is interpreted to involve initial accretion and subduction-zone metamorphism south of the present locality, uplift and exhumation, orogen-parallel northward transport of the nappes as part of a forearc sliver, and finally obduction at the present site over the truncated south end of Wrangellia and the Coast Plutonic Complex.

scholarly journals Late Cretaceous-Cenozoic Exhumation of the Western Brooks Range, Alaska, Revealed From Apatite and Zircon Fission Track Data

Tectonics ◽  
2018 ◽  
Vol 37 (12) ◽  
pp. 4714-4751 ◽  
Author(s):  
William H. Craddock ◽  
Thomas E. Moore ◽  
Paul B. O'Sullivan ◽  
Christopher J. Potter ◽  
David W. Houseknecht
Keyword(s):  
Late Cretaceous ◽  
Fission Track ◽  
Brooks Range ◽  
Zircon Fission Track

scholarly journals Resolution of the age structure of the detrital zircon populations of two Lower Cretaceous sandstones from the Weald of England by fission track dating

1984 ◽  
Vol 121 (4) ◽  
pp. 269-277 ◽  
Author(s):  
A. J. Hurford ◽  
F. J. Fitch ◽  
A. Clarke
Keyword(s):  
Detrital Zircon ◽  
Lower Cretaceous ◽  
Fission Track ◽  
Age Distribution ◽  
The Other ◽  
Fission Track Dating ◽  
Zircon Age ◽  
Zircon Fission Track ◽  
Geological Implications ◽  
Fission Track Ages

AbstractModes in the frequency of distribution of fission track ages obtained from detrital zircon grains may prove characteristic of individual sandstone bodies, supporting the identification of the sources from which a particular flow of sedimentary detritus was derived and thus allowing new inferences to be made concerning palaeogeography. A computer program has been written and used to identify modes in the zircon fission track age distribution within two Lower Cretaceous sandstone samples from the Weald of southern England. Pronounced modes appear in one rock around 119 Ma, 160 Ma, 243 Ma and 309 Ma and in the other around 141 Ma, 175 Ma, 257 to 277 Ma and 394 to 453 Ma. The geological implications of these quite dissimilar zircon age spectra are discussed. It is concluded that they support the palaeogeographical models of Allen (1981) and indicate that the provenance of the first sample, from the Top Ashdown Sandstone member at Dallington in East Sussex, was almost entirely southerly, while that of the second, from the Netherside Sand member at Northchapel in West Sussex, was more varied, but predominantly westerly and northerly.

scholarly journals Birth and closure of the Kallipetra Basin: Late Cretaceous reworking of the Jurassic Pelagonian–Axios/Vardar contact (northern Greece)

Solid Earth ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 2463-2485
Author(s):  
Lydia R. Bailey ◽  
Filippo L. Schenker ◽  
Maria Giuditta Fellin ◽  
Miriam Cobianchi ◽  
Thierry Adatte ◽  
...  
Keyword(s):  
Fission Track ◽  
Geothermal Gradient ◽  
Middle Part ◽  
Normal Faults ◽  
Illite Crystallinity ◽  
Northern Greece ◽  
Basin Inversion ◽  
Zircon Fission Track ◽  
Fission Track Ages ◽  
Fault Scarps

Abstract. Some 20 Myr after the Late Jurassic to Early Cretaceous obduction and collision at the eastern margin of Adria, the eroded Pelagonia (Adria)–Axios/Vardar (oceanic complex) contact collapsed, forming the Kallipetra Basin, described around the Aliakmon River near Veroia (northern Greece). Clastic and carbonate marine sediments deposited from the early Cenomanian to the end of the Turonian, with abundant olistoliths and slope failures at the base due to active normal faults. The middle part of the series is characterized by red and green pelagic limestones, with a minimal contribution of terrigenous debris. Rudist mounds in the upper part of the basin started forming on the southwestern slope, and their growth competed with a flux of ophiolitic debris, documenting the new fault scarps affecting the Vardar oceanic complex (VOC). Eventually, the basin was closed by overthrusting of the VOC towards the northeast and was buried and heated up to ∼ 180 ∘C. A strong reverse geothermal gradient with temperatures increasing up-section to near 300 ∘C is recorded beneath the VOC by illite crystallinity and by the crystallization of chlorite during deformation. This syntectonic heat partially reset the zircon fission track ages bracketing the timing of closure just after the deposition of the ophiolitic debris in the Turonian. This study documents the reworking of the Pelagonian–Axios/Vardar contact, with Cenomanian extension and basin widening followed by Turonian compression and basin inversion. Thrusting occurred earlier than previously reported in the literature for the eastern Adria and shows a vergence toward the northeast, at odds with the regional southwest vergence of the whole margin but in accordance to some reports about 50 km north.

The Tectonic and Uplift History of the Kuruketage Area in the North-East Edge of the Tarim Basin, China: Constraints from Detrital Zircon and Apatite Fission Track Data

2013 ◽  
Vol 330 ◽  
pp. 1067-1070
Author(s):  
Hui Xiao ◽  
Wei Han ◽  
Feng Guo
Keyword(s):  
Late Cretaceous ◽  
Tarim Basin ◽  
Fission Track ◽  
Vitrinite Reflectance ◽  
Early Paleozoic ◽  
Apatite Fission Track ◽  
North East ◽  
Zircon Fission Track ◽  
History Of ◽  
Uplift History

This study uses the application of zircon fission track (ZFT) and apatite fission track (AFT) thermochronometry technique to investigate the tectonic and uplift history of the Kuruketage area, north-east edge of the Tarim Basin. Based on measured ZFT, AFT and equivalent vitrinite reflectance measurements of samples in sedimentary rocks in Kuruketage area, the temperature time evolution history from early Paleozoic strata was modeled. The results show that the youngest peaks of ZFT at 371-392Ma and 328 - 305.7Ma record Hercynian tectonic and uplift event; the AFT peaks at 134.5 - 164Ma, 73 - 100Ma and 35.4Ma mainly represent the Late-Cretaceous tectonic and uplift event in Kuruketage area. The AFT thermal modeling results from the early Paleozoic strata indicate that the maximum paleo-temperature (at 140 215°C) experienced in late Silurian to early Devonian, and the strata temperature decreased to about 120°C before the Late-Cretaceous.

scholarly journals Distributional patterns of ?Mawsoniidae (Sarcopterygii: Actinistia)

2014 ◽  
Vol 86 (1) ◽  
pp. 159-170 ◽  
Author(s):  
RAPHAEL MIGUEL ◽  
VALÉRIA GALLO ◽  
JUAN J. MORRONE
Keyword(s):  
Southern Hemisphere ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
Tectonic Events ◽  
Distributional Patterns ◽  
Track Analysis

Mawsoniidae are a fossil family of actinistian fish popularly known as coelacanths, which are found in continental and marine paleoenvironments. The taxon is considered monophyletic, including five valid genera (Axelrodichthys, Chinlea, Diplurus, Mawsonia and Parnaibaia) and 11 genera with some taxonomical controversy (Alcoveria, Changxingia, Garnbergia, Heptanema, Indocoelacanthus, Libys, Lualabaea, Megalocoelacanthus, Moenkopia, Rhipis and Trachymetopon). The genera restricted to the Northern Hemisphere (Diplurus and Chinlea) possess the oldest records (Late Triassic), whereas those found in the Southern Hemisphere (Mawsonia, Axelrodichthys, and Parnaibaia) extend from Late Jurassic to Late Cretaceous, especially in Brazil and Africa. We identified distributional patterns of Mawsoniidae, applying the panbiogeographical method of track analysis, and obtained three generalized tracks (GTs): GT1 (Northeastern Newark) in strata of the Newark Group (Upper Triassic); GT2 (Midwestern Gondwana) in the Lualaba Formation (Upper Jurassic); and GT3 (Itapecuru-Alcântara-Santana) in the Itapecuru-Alcântara-Santana formations (Lower Cretaceous). The origin of Mawsoniidae can be dated to at least Late Triassic of Pangaea. The tectonic events related to the breakup of Pangaea and Gondwana and the evolution of the oceans are suggested as the vicariant events modeling the distribution of this taxon throughout the Mesozoic.

Fission-track analysis unravels the denudation history of the Bonar Range in the footwall of the Alpine Fault, South Island, New Zealand

2010 ◽  
Vol 147 (6) ◽  
pp. 801-813 ◽  
Author(s):  
UWE RING ◽  
MATTHIAS BERNET
Keyword(s):  
New Zealand ◽  
Late Cretaceous ◽  
Fission Track ◽  
Southern Alps ◽  
Exhumation Rate ◽  
Alpine Fault ◽  
Zircon Fission Track ◽  
Fission Track Thermochronology ◽  
Late Tertiary ◽  
History Of

AbstractWe apply fission-track thermochronology to shed new light on the tectonic history of Zealandia during Late Cretaceous continental extension and the onset of Late Tertiary mountain building in the Southern Alps of New Zealand. The Southern Alps are one of the fastest erosionally exhuming mountain belts on Earth. Exhumation of the Bonar Range in Westland just to the northwest of the Alpine Fault is orders of magnitude slower. We report apatite and zircon fission-track ages from samples that were collected along an ENE–WSW profile across the central Bonar Range, parallel to the tectonic transport direction of a prominent ductile fabric in the basement gneiss. Zircon fission-track (ZFT) ages show a large spread from 121.9 ± 12.1 Ma to 74.9 ± 7.2 Ma (1σ errors). The youngest ZFT ages of 78 to 75 Ma occur at low elevations on either side of the Bonar Range and become older towards the top of the range, thereby showing a symmetric pattern parallel to the ENE-trending profile across the range. Age–elevation relationships suggest an exhumation rate of 50–100 m Ma−1. We relate the ZFT ages to slow erosion of a tectonically inactive spot in the Late Cretaceous magmatic arc of Zealandia. Therefore, the first main significance of the paper is that it demonstrates that not all of 110–90 Ma Zealandia was necessarily participating in extreme core complex-related extension but that there were enclaves of lithosphere that underwent slow erosion. The apatite fission-track (AFT) ages range from 11.1 ± 1.9 Ma to 5.3 ± 1.0 Ma and age–elevation relationships suggest an exhumation rate of c. 200 m Ma−1. We relate the AFT ages to the inception of transpressive motion across the Alpine Fault and modest exhumation in its footwall in Late Miocene times. If so, the second significant point of this paper is that transpressive motion across the Alpine Fault was already under way by c. 11 Ma.

scholarly journals Supplemental Material: Cenozoic tectonic evolution of the Ecemiş fault zone and adjacent basins, central Anatolia, Turkey during the transition from Arabia-Eurasia collision to escape tectonics

2020 ◽  
Author(s):  
P.J. Umhoefer ◽  
et al.
Keyword(s):  
Fault Zone ◽  
Tectonic Evolution ◽  
Fission Track ◽  
Volcanic Rocks ◽  
Detrital Zircons ◽  
Central Anatolia ◽  
Zircon Fission Track ◽  
Escape Tectonics

Consists of geochronology and thermochronology data, and methods related to those data. Geochronology data are from <sup>40</sup>Ar/<sup>39</sup>Ar dating of volcanic rocks and U-Pb analysis of detrital zircons, while thermochronology data are from apatite and zircon fission-track and apatite helium cooling ages.

scholarly journals Thermal history of the Maramureş area (Northern Romania) constrained by zircon fission track analysis: Cretaceous metamorphism and Late Cretaceous to Paleocene exhumation

2013 ◽  
Vol 64 (5) ◽  
pp. 383-398 ◽  
Author(s):  
Heike R. Gröger ◽  
Matthias Tischler ◽  
Bernhard Fügenschuh ◽  
Stefan M. Schmid
Keyword(s):  
Late Cretaceous ◽  
Thermal History ◽  
Fission Track ◽  
Structural Evolution ◽  
Published Data ◽  
Metamorphic Overprint ◽  
Sedimentary Evolution ◽  
Zircon Fission Track ◽  
Eastern Carpathians ◽  
History Of

Abstract This study presents zircon fission track data from the Bucovinian nappe stack (northern part of the Inner Eastern Carpathians, Rodna Mountains) and a neighbouring part of the Biharia nappe system (Preluca massif) in order to unravel the thermal history of the area and its structural evolution by integrating the fission track data with published data on the tectonic and sedimentary evolution of the area. The increase of metamorphic temperatures towards the SW detected by the zircon fission track data suggests SW-wards increasing tectonic overburden (up to at least 15 km) and hence top NE thrusting. Sub-greenschist facies conditions during the Alpine metamorphic overprint only caused partial annealing of fission tracks in zircon in the external main chain of the Central Eastern Carpathians. Full annealing of zircon points to at least 300 °C in the more internal elements (Rodna Mountains and Preluca massif). The zircon fission track central and single grain ages largely reflect Late Cretaceous cooling and exhumation. A combination of fission track data and stratigraphic constraints points to predominantly tectonic differential exhumation by some 7-11 km, connected to massive Late Cretaceous extension not yet detected in the area. Later events such as the latest Cretaceous (“Laramian”) juxtaposition of the nappe pile with the internal Moldavides, causing exhumation by erosion, re-burial by sedimentation and tectonic loading during the Cenozoic had no impact on the zircon fission track data; unfortunately it prevented a study of the low temperature part of the Late Cretaceous exhumation history.

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