Identifying the post-sedimentary part of fission track length histograms with inherited tracks

2018 ◽  
Author(s):  
Peter Klint Jensen ◽  
Kirsten Hansen
Keyword(s):  
Fission Track ◽  
Track Length

Some calculations relevant to thermal annealing of fission tracks in apatite

1988 ◽  
Vol 419 (1857) ◽  
pp. 305-321 ◽  
Keyword(s):  
Conditional Distribution ◽  
Fission Track ◽  
Length Distribution ◽  
Track Length ◽  
Apatite Crystal ◽  
Routine Practice ◽  
Fission Tracks ◽  
Line Segments ◽  
Segment Model ◽  
Arbitrary Plane

Calculations in stochastic geometry are applied to the geological problem of analysing the statistical distribution of fission tracks in an apatite crystal, when information is available only by plane sampling. The feature of particular interest is the effect of anisotropy, in the sense of dependence of track length on orientation. Using a realistic Poisson line-segment model, we obtain formulae for the density of line segments intersecting an arbitrary plane and for the length distributions of confined tracks, semi-tracks and projected semi-tracks in terms of the conditional distribution of length given orientation. These formulae are used to explain and quantify the effect of anisotropy seen in experimental data from fission track annealing studies. We argue that track orientations, in addition to lengths, carry potentially useful information. For confined tracks, we recommend that both length and angle to the c -axis be measured as routine practice. For projected semi-tracks, where it is much harder to extract useful information from the observed length distribution, the measurement of angle, in addition to length, may prove fruitful, particularly when confined tracks are scarce.

Apatite fission-track age correction and thermal history analysis from projected track length distributions

1993 ◽  
Vol 103 (1-4) ◽  
pp. 157-169
Author(s):  
M. Grivet ◽  
M. Rebetez ◽  
N. Ben Ghouma ◽  
A. Chambaudet ◽  
R. Jonckheere ◽  
...  
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Track Length ◽  
Apatite Fission Track ◽  
History Analysis ◽  
Age Correction

Reproducibility of apatite fission-track length data and thermal history reconstruction

2009 ◽  
Vol 284 (3-4) ◽  
pp. 504-515 ◽  
Author(s):  
Richard A. Ketcham ◽  
Raymond A. Donelick ◽  
Maria Laura Balestrieri ◽  
Massimiliano Zattin
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Track Length ◽  
Apatite Fission Track ◽  
Length Data

Thermochronologic constraints on ore formation at the Gays River Pb–Zn deposit, Nova Scotia, Canada, from apatite fission track analysis

1990 ◽  
Vol 27 (8) ◽  
pp. 1013-1022 ◽  
Author(s):  
Dennis C. Arne ◽  
Ian R. Duddy ◽  
Don F. Sangster
Keyword(s):  
Nova Scotia ◽  
Fission Track ◽  
Track Length ◽  
Late Paleozoic ◽  
Apatite Fission Track ◽  
Ore Formation ◽  
Sulphide Mineralization ◽  
Fission Track Ages ◽  
Uplift And Erosion ◽  
Host Rocks

Fission tracks in detrital apatites from the Cambro-Ordovician metasedimentary basement in the vicinity of the Carboniferous-hosted Gays River Pb–Zn deposit, Nova Scotia, provide a record of final cooling during uplift and erosion of the Meguma Zone and constrain the timing of ore formation. Apatite fission track ages range from 203 to 241 Ma, with typical uncertainties of ± 10 Ma. Mean confined track lengths generally vary between 12.0 and 13.4 μm and indicate that the apatites record "apparent" ages only. An inferred thermal history involving regional heating to paleotemperatures > 110 °C during late Paleozoic burial followed by cooling to ~ 110 °C prior to 240–220 Ma is suggested. A more recent phase or regional heating to paleotem-peratures probably in the range of 60–80 °C during Late Cretaceous – early Tertiary (ca. 100–50 Ma) burial is also indicated by the track length data. Apatite fission track ages and mean track lengths from drill-core samples immediately beneath the Gays River orebody are similar to those for regional outcrop samples. At minimum temperatures > 200 °C estimated for ore formation, sulphide mineralization must either have preceded or accompanied regional heating to paleotemperatures > 110 °C during the late Paleozoic. Sulphide mineralization at Gays River must therefore have taken place at some time after ca. 330 Ma (the stratigraphic age of the lower Windsor Group host rocks) but before ca. 240–220 Ma (the last cooling of Meguma Group basement below 110 °C). These constraints on the timing of ore formation at Gays River are compatible with previous suggestions that Pb–Zn mineralization of Carboniferous strata in Nova Scotia occurred at ca. 300 Ma.

scholarly journals Short communication concerning experimental factors affecting fission-track counts in apatite

2021 ◽  
Author(s):  
Carolin Aslanian ◽  
Raymond Jonckheere ◽  
Bastian Wauschkuhn ◽  
Lothar Ratschbacher
Keyword(s):  
Short Communication ◽  
Fission Track ◽  
Track Length ◽  
Severe Restriction ◽  
Related Factors ◽  
Factors Affecting ◽  
Provenance Studies ◽  
Etched Surface ◽  
Track Counts ◽  
Better Than

Abstract. The tools for interpreting fission-track data are evolving apace but, even so, the outcomes cannot be better than the data. Recent studies that have again taken up the issues of etching and observation have shown that both have an effect on confined-track length measurements. We report experiments concerning the effects of grain orientation, polishing, etching and observation on fission-track counts in apatite. The results cannot be generalized to circumstances other than those of the experiments, and thus do not solve the problems of track counting. Our findings nevertheless throw light on the factors affecting the track counts, and thence the sample ages, whilst raising the question: what counts as an etched surface track? This is pertinent to manual and automatic track counts and to designing training strategies for neural networks. We cannot be confident that counting prism faces and using the ζ-calibration for age calculation are adequate for dealing with all etching- and counting-related factors across all samples. Prism faces are not unproblematic for counting and other surface orientations are not per se useless. Our results suggest that a reinvestigation of the etching properties of different apatite faces could increase the range useful for dating, and so lift a severe restriction for provenance studies.

Burial and exhumation of the Long Range Inlier and its surroundings, western Newfoundland: results of an apatite fission-track study

1993 ◽  
Vol 30 (8) ◽  
pp. 1594-1606 ◽  
Author(s):  
M. Hendriks ◽  
R. A. Jamieson ◽  
S. D. Willett ◽  
M. Zentilli
Keyword(s):  
Long Range ◽  
Fission Track ◽  
Sedimentary Cover ◽  
Early Carboniferous ◽  
Track Length ◽  
Lake Basin ◽  
Apatite Fission Track ◽  
Slow Cooling ◽  
Base Level ◽  
Thermal Histories

The Long Range Inlier, a steep-sided plateau underlain mainly by Grenvillian gneisses, is the most prominent topographic feature of western Newfoundland. Apatite fission-track analysis of 31 samples from the Long Range Inlier and its surroundings yielded measured apparent ages of 343–152 Ma. Age versus elevation plots, track-length distributions, and model thermal histories indicate that the region experienced slow cooling in the late Paleozoic, with apparent exhumation rates of 7–9 m∙Ma−1 and cooling rates of 0.08–0.28 °C∙Ma−1. Model thermal histories suggest that the present upper surface of the Long Range plateau cooled below ~120 °C in Ordovician times. The thermal histories are compatible with, but do not require, some exhumation of the Long Range Inlier along Acadian thrust faults. Results from Early Carboniferous sedimentary rocks of the Deer Lake Basin are similar to Long Range Inlier data from similar elevations, implying that at some time between ~350 and 300 Ma, the entire region was buried to depths sufficient to induce total annealing (T > 120 °C) in these samples. Closure ages determined from model thermal histories indicate that regional cooling to temperatures below ~120 °C began before 300 Ma. The Carboniferous sedimentary cover was largely removed by Jurassic time, perhaps in response to lowering of regional base level by rifting associated with the opening of the Atlantic Ocean.

Further investigation of the initial fission-track length and geometry factor in apatite fission-track thermochronology

2013 ◽  
Vol 98 (8-9) ◽  
pp. 1381-1392 ◽  
Author(s):  
C. J. Soares ◽  
S. Guedes ◽  
C. A. Tello ◽  
A. L. Lixandrao Filho ◽  
A. M. Osorio ◽  
...  
Keyword(s):  
Fission Track ◽  
Track Length ◽  
Apatite Fission Track ◽  
Geometry Factor ◽  
Fission Track Thermochronology
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