scholarly journals Simulating sedimentary burial cycles – Part 2: Elemental-based multikinetic apatite fission-track interpretation and modelling techniques illustrated using examples from northern Yukon

2021 ◽  
Author(s):  
Dale R. Issler ◽  
Kalin T. McDannell ◽  
Paul B. O'Sullivan ◽  
Larry S. Lane
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Learning Algorithm ◽  
Random Search ◽  
Apatite Fission Track ◽  
Significance Level ◽  
Aft Model ◽  
Heating And Cooling ◽  
Thermal Histories ◽  
Consistent Assessment

Abstract. Compositionally dependent apatite fission track (AFT) annealing is a common but underappreciated cause for age dispersion in detrital AFT samples. We present an interpretation and modelling strategy that exploits multikinetic AFT annealing to obtain thermal histories that can provide more detail and better resolution compared to conventional methods. We illustrate our method using a Permian and a Devonian sample from the Yukon, Canada, both with complicated geological histories and long residence times in the AFT partial annealing zone. Effective Cl values (eCl; converted from rmr0 values), derived from detailed apatite elemental data, are used to define AFT statistical kinetic populations with significantly different total annealing temperatures (~110–245 °C) and ages that agree closely with the results of age mixture modelling. These AFT populations are well-resolved using eCl values but exhibit significant overlap with respect to the conventional parameters, Cl content or Dpar. Elemental analyses and measured Dpar for Phanerozoic samples from the Yukon and Northwest Territories confirm that Dpar has low precision and that Cl content alone cannot account for the compositional and associated kinetic variability observed in natural samples. An inverse multikinetic AFT model, AFTINV, is used to obtain thermal history information by simultaneously modelling multiple kinetic populations as distinct thermochronometers with different temperature sensitivities. A nondirected Monte Carlo scheme generates a set of statistically acceptable solutions at the 0.05 significance level and then these solutions are updated to the 0.5 level using a controlled random search (CRS) learning algorithm. The smoother, closer-fitting CRS solutions allow for a more consistent assessment of the eCl values and thermal history styles that are needed to satisfy the AFT data. The high-quality Devonian sample (39 single grain ages and 202 track lengths) has two kinetic populations that require three cycles of heating and cooling (each subsequent event of lower intensity) to obtain close-fitting solutions. The younger and more westerly Permian sample with three kinetic populations only records the latter two heating events. These results are compatible with known stratigraphic and thermal maturity constraints and the QTQt software produces similar results. Model results for these and other samples suggest that elemental-derived eCl values are accurate within the range, 0–0.25 apfu (rmr0 values of 0.73–0.84), which encompasses most of the data from annealing experiments. Outside of this range, eCl values for more exotic compositions may require adjustment relative to better constrained apatite compositions when trying to fit multiple kinetic populations. Our results for natural and synthetic samples suggest that an element-based multikinetic approach has great potential to increase the temperature range and resolution of thermal histories dramatically relative to conventional AFT thermochronology.

Resolving thermal histories via multi-kinetic apatite fission track data: A case study from Phanerozoic strata within the Peel Plateau NWT, Canada

2021 ◽  
Author(s):  
Jennifer Spalding ◽  
Jeremy Powell ◽  
David Schneider ◽  
Karen Fallas
Keyword(s):  
Low Temperature ◽  
Thermal History ◽  
Fission Track ◽  
Sedimentary Basins ◽  
Source Rocks ◽  
Apatite Fission Track ◽  
Petroleum Systems ◽  
History Of ◽  
Thermal Histories ◽  
Peel Plateau

<p>Resolving the thermal history of sedimentary basins through geological time is essential when evaluating the maturity of source rocks within petroleum systems. Traditional methods used to estimate maximum burial temperatures in prospective sedimentary basin such as and vitrinite reflectance (%Ro) are unable to constrain the timing and duration of thermal events. In comparison, low-temperature thermochronology methods, such as apatite fission track thermochronology (AFT), can resolve detailed thermal histories within a temperature range corresponding to oil and gas generation. In the Peel Plateau of the Northwest Territories, Canada, Phanerozoic sedimentary strata exhibit oil-stained outcrops, gas seeps, and bitumen occurrences. Presently, the timing of hydrocarbon maturation events are poorly constrained, as a regional unconformity at the base of Cretaceous foreland basin strata indicates that underlying Devonian source rocks may have undergone a burial and unroofing event prior to the Cretaceous. Published organic thermal maturity values from wells within the study area range from 1.59 and 2.46 %Ro for Devonian strata and 0.54 and 1.83 %Ro within Lower Cretaceous strata. Herein, we have resolved the thermal history of the Peel Plateau through multi-kinetic AFT thermochronology. Three samples from Upper Devonian, Lower Cretaceous and Upper Cretaceous strata have pooled AFT ages of 61.0 ± 5.1 Ma, 59.5 ± 5.2 and 101.6 ± 6.7 Ma, respectively, and corresponding U-Pb ages of 497.4 ± 17.5 Ma (MSWD: 7.4), 353.5 ± 13.5 Ma (MSWD: 3.1) and 261.2 ± 8.5 Ma (MSWD: 5.9). All AFT data fail the χ<sup>2</sup> test, suggesting AFT ages do not comprise a single statistically significant population, whereas U-Pb ages reflect the pre-depositional history of the samples and are likely from various provenances. Apatite chemistry is known to control the temperature and rates at which fission tracks undergo thermal annealing. The r<sub>mro</sub> parameter uses grain specific chemistry to predict apatite’s kinetic behaviour and is used to identify kinetic populations within samples. Grain chemistry was measured via electron microprobe analysis to derive r<sub>mro</sub> values and each sample was separated into two kinetic populations that pass the χ<sup>2</sup> test: a less retentive population with ages ranging from 49.3 ± 9.3 Ma to 36.4 ± 4.7 Ma, and a more retentive population with ages ranging from 157.7 ± 19 Ma to 103.3 ± 11.8 Ma, with r<sub>mr0</sub> benchmarks ranging from 0.79 and 0.82. Thermal history models reveal Devonian strata reached maximum burial temperatures (~165°C-185°C) prior to late Paleozoic to Mesozoic unroofing, and reheated to lower temperatures (~75°C-110°C) in the Late Cretaceous to Paleogene. Both Cretaceous samples record maximum burial temperatures (75°C-95°C) also during the Late Cretaceous to Paleogene. These new data indicate that Devonian source rocks matured prior to deposition of Cretaceous strata and that subsequent burial and heating during the Cretaceous to Paleogene was limited to the low-temperature threshold of the oil window. Integrating multi-kinetic AFT data with traditional methods in petroleum geosciences can help unravel complex thermal histories of sedimentary basins. Applying these methods elsewhere can improve the characterisation of petroleum systems.</p>

scholarly journals Simulating sedimentary burial cycles: Investigating the role of apatite fission track annealing kinetics using synthetic data

2020 ◽  
Author(s):  
Kalin T. McDannell ◽  
Dale R. Issler
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Model Simulation ◽  
Damage Model ◽  
Synthetic Data ◽  
Companion Paper ◽  
Time Interval ◽  
Apatite Fission Track ◽  
Heating And Cooling ◽  
Improve Model

Abstract. Age dispersion is a common feature of apatite fission track (AFT) and apatite (U-Th)/He (AHe) thermochronological data and it can be attributed to multiple factors. One underappreciated and underreported cause for dispersion is variability in apatite composition and its influence on thermal annealing of fission tracks. Here we investigate, using synthetic data, how multikinetic AFT annealing behaviour (defined using the rmr0 parameter) can be exploited to recover more accurate, higher resolution thermal histories than are possible using conventional interpretation and modelling approaches. Our forward model simulation spans a 2 Gyr time interval with two separate heating and cooling cycles and generates synthetic AFT and AHe data for three different apatite populations with significantly different annealing kinetics. The synthetic data are used as input for inverse modelling (Bayesian QTQt model) that attempts to recover thermal history information under various scenarios. Results show that essential features of the dual peak thermal history are captured using the multikinetic AFT data alone, with or without imposed constraints. Best results are achieved when the multikinetic AFT data are combined with the AHe data (using varying rmr0 values from the AFT data for the He radiation damage model) and constraints are included. In contrast, a more conventional monokinetic interpretation that ignores multikinetic AFT behaviour yields incorrect thermal solutions that fail to adequately reproduce all the data. The AFT data are reproduced well but the AHe data are not. Under these conditions, incorporation of constraints can be very misleading and fail to improve model results. In general, a close fit between observed and modelled parameters is no guarantee of a robust thermal-history solution if data are incorrectly interpreted. For the case of overdispersed AFT data, it is strongly recommended that elemental data be acquired to investigate if multikinetic annealing is the cause of the age scatter. A future companion paper will explore multikinetic AFT methodology and application to detrital apatite samples from Yukon, Canada.

Apatite fission track data from southeast Ireland: implications for post-Variscan burial history

1993 ◽  
Vol 130 (2) ◽  
pp. 171-176 ◽  
Author(s):  
M. L. Keeley ◽  
C. L. E. Lewis ◽  
G. D. Sevastopulo ◽  
G. Clayton ◽  
R. Blackmore
Keyword(s):  
Fission Track ◽  
Variscan Orogeny ◽  
Apatite Fission Track ◽  
Burial History ◽  
Northern Margin ◽  
The North ◽  
Heating And Cooling ◽  
Length Data ◽  
Thermal Histories ◽  
And Inversion

AbstractThe results of a reconnaissance apatite fission track study from southeast Ireland are compared with modelled ages and length distributions predicted using both traditional thermal histories and the thermal history indicated by the fission track age and length data. All samples have experienced total annealing during the Variscan orogeny. There is strong evidence for significant post-Variscan, pre-Mid Jurassic heating and cooling. The modelling also recognizes a third thermal event subsequent to 100 Ma. The implications of these results are examined in terms of the timing and extent of subsidence and inversion along the northern margin of the North Celtic Sea Basin.

Thermal history modelling of the western margin of the Bohemian Massif using high-resolution apatite fission-track thermochronology

2020 ◽  
Author(s):  
Lucie Novakova ◽  
Raymond Jonckheere ◽  
Bastian Wauschkuhn ◽  
Lothar Ratchbacher
Keyword(s):  
High Resolution ◽  
Bohemian Massif ◽  
Thermal History ◽  
Fission Track ◽  
Track Length ◽  
Apatite Fission Track ◽  
Fission Track Thermochronology ◽  
Length Measurements ◽  
Thermal Histories ◽  
Fission Track Ages

<p>The Naab area is situated on the western border of the Bohemian Massif, 60 km south of the KTB (Kontinentalen Tiefbohrung). The main super-deep borehole of the KTB reached a depth of 9,101 meters in the Earth's continental crust. The fission-track data for the KTB and the Naab area present contrasting signatures. The apatite fission-track ages in the upper section of the KTB borehole and surrounding area are in the range 50-70 Ma (Wagner et al., 1994; Wauschkuhn et al., 2015). The apatite fission-track ages of the Naab basement are older than those of the KTB area, and span a broader range: 120-200 Ma (Vercoutere, 1994). The distributions of the confined-track lengths range from unimodal over skewed and mixed to bimodal, with mean lengths in the range 11-13 µm. In broad terms, this can be interpreted as that the Naab samples contain both an older and younger (in particular pre- and post-late Cretaceous) fission-track population. The aim of our research is to investigate the applicability of lab-based models to geological data, using improved measurement techniques.</p><p>We studied eighteen samples dated by Vercoutere (1994) from the Palaeozoic basement and seven large rock samples from the Rotliegend strata north of the Luhe fault.  We intend to extend the confined-track length measurements of Vercoutere (1994), aiming to achieve higher resolution through methodological innovations made possible by computer-controlled motorized microscopes. Improved statistics increase the resolution of the modelled thermal histories, which permits to better distinguish systematic from statistical differences between the modelled palaeotemperatures and geological estimates. Experiments have shown that the rate of length increase permits to distinguish older from younger tracks (Jonckheere et al., 2017). This allows us to distinguish between tracks formed before and after the Late Cre­taceous to Palaeocene exhumation. The etch rate of a confined track is also an indicator of its individual thermal history, supplementing the information gleaned from its etchable length under fixed conditions. We compiled a comprehensive, high-resolution confined-track-length dataset. The Naab thermal histories were determined using modern modelling algorithms, implementing the most recent empirical equations.</p><p><strong>References</strong></p><p>Jonckheere R., Tamer M., Wauschkuhn F., Wauschkuhn B., Ratschbacher L., 2017. Single-track length measurements of step-etched fission tracks in Durango apatite: Vorsprung durch Technik.American Mineralogist 102, 987-996.</p><p>Vercoutere C., 1994. The thermotectonic history of the Brabant Massif (Belgium) and the Naab Basement (Germany):   an apatite fission track analysis. Ph. D. thesis, Universiteit Gent, pp. 191.</p><p>Wagner G.A., Hejl E., Van Den Haute P., 1994. The KTB fission-track project: Methodical aspects and geological implications. Radiation Measurements 23, 95-101.</p><p>Wauschkuhn B., Jonckheere R., Ratschbacher L., 2015. The KTB apatite fission-track profiles: building on a firm foundation? Geochimica et Cosmochimica Acta 167, 27-62.</p>

scholarly journals Simulating sedimentary burial cycles – Part 1: Investigating the role of apatite fission track annealing kinetics using synthetic data

Geochronology ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 321-335
Author(s):  
Kalin T. McDannell ◽  
Dale R. Issler
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Model Simulation ◽  
Synthetic Data ◽  
Companion Paper ◽  
Time Interval ◽  
Apatite Fission Track ◽  
Heating And Cooling ◽  
Improve Model ◽  
Elemental Analyses

Abstract. Age dispersion is a common feature of apatite fission track (AFT) and apatite (U–Th) / He (AHe) thermochronological data, and it can be attributed to multiple factors. One underappreciated and underreported cause for dispersion is variability in apatite composition and its influence on thermal annealing of fission tracks. Using synthetic data we investigate how multikinetic AFT annealing behaviour, defined using the rmr0 parameter, can be exploited to recover more accurate, higher-resolution thermal histories than are possible using conventional interpretation and modelling approaches. Our forward model simulation spans a 2 Gyr time interval with two separate heating and cooling cycles and was used to generate synthetic AFT and AHe data for three different apatite populations with significantly different annealing kinetics. The synthetic data were then used as input for inverse modelling in the Bayesian QTQt software to recover thermal-history information under various scenarios. Results show that essential features of the dual peak thermal history are captured using the multikinetic AFT data alone, with or without imposed constraints. Best results are achieved when the multikinetic AFT data are combined with the AHe data and geologic constraint boxes are included. In contrast, a more conventional monokinetic interpretation that ignores multikinetic AFT behaviour reproduces all the input data but yields incorrect thermal-history solutions. Under these conditions, incorporation of constraints can be misleading and fail to improve model results. In general, a close fit between observed and modelled parameters is no guarantee of a robust thermal-history solution if data are incorrectly interpreted. For the case of overdispersed AFT data, it is strongly recommended that elemental data be acquired to investigate if multikinetic annealing is the cause of the AFT apparent age scatter. Elemental analyses can also be similarly useful for broadly assessing AHe data. A future companion paper (Issler et al., 2021) will explore multikinetic AFT methodology and application to detrital apatite samples from Yukon, Canada.

scholarly journals Supplemental Material: Thermochronological transect across the Basin and Range/Rio Grande rift transition: Contrasting cooling histories in contiguous extensional provinces

2021 ◽  
Author(s):  
M.M. Gavel ◽  
et al. ◽  
J. Amato
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Rio Grande ◽  
Basin And Range ◽  
Rio Grande Rift ◽  
Apatite Fission Track

<div>Table S1: Summary of all of the geochronology (dates and locations) for the samples in this study. Table S2: Thermal history model inputs; Table S3: Apatite fission track data used in HeFTy modeling.<br></div><div><br></div><div><br></div><div><br></div>

Thermal history of the Siberian platform: Apatite Fission-Track data from the Permian-Triassic magmatic complexes

2021 ◽  
Author(s):  
Tatyana Bagdasaryan ◽  
Roman Veselovskiy ◽  
Viktor Zaitsev ◽  
Anton Latyshev
Keyword(s):  
Siberian Platform ◽  
Thermal History ◽  
Fission Track ◽  
Sedimentary Cover ◽  
Geothermal Gradient ◽  
State University ◽  
Apatite Fission Track ◽  
History Of ◽  
Cover Up ◽  
Moscow State University

&lt;p&gt;The largest continental igneous province, the Siberian Traps, was formed within the Siberian platform at the Paleozoic-Mesozoic boundary, ca. 252 million years ago. Despite the continuous and extensive investigation of the duration and rate of trap magmatism on the Siberian platform, these questions are still debated. Moreover, the post-Paleozoic thermal history of the Siberian platform is almost unknown. This study aims to reconstruct the thermal history of the Siberian platform during the last 250 Myr using the low-temperature thermochronometry. We have studied intrusive complexes from different parts of the Siberian platform, such as the Kotuy dike, the Odikhincha, Magan and Essey ultrabasic alkaline massifs, the Norilsk-1 and Kontayskaya intrusions, and the Padunsky sill. We use apatite fission-track (AFT) thermochronology to assess the time since the rocks were cooled below 110&amp;#8451;. Obtained AFT ages (207-173 Ma) are much younger than available U-Pb and Ar/Ar ages of the traps. This pattern might be interpreted as a long cooling of the studied rocks after their emplacement ca. 250 Ma, but this looks quite unlikely because contradicts to the geological observations. Most likely, the rocks were buried under a thick volcanic-sedimentary cover and then exhumed and cooled below 110&amp;#8451; ca. 207-173 Ma. Considering the increased geothermal gradient up to 50&amp;#8451;/km at that times, we can estimate the thickness of the removed overlying volcanic-sedimentary cover up to 207-173 Ma as about 2-3 km.&lt;/p&gt;&lt;p&gt;The research was carried out with the support of RFBR (grants 20-35-90066, 18-35-20058, 18-05-00590 and 18-05-70094) and the Program of development of Lomonosov Moscow State University.&lt;/p&gt;

SEDIMENT SUPPLY TO THE GIPPSLAND BASIN FROM THERMAL HISTORY ANALYSIS: CONSTRAINTS ON EMPEROR—GOLDEN BEACH RESERVOIR COMPOSITION

2004 ◽  
Vol 44 (1) ◽  
pp. 397 ◽  
Author(s):  
U.D. Weber ◽  
K.C. Hill ◽  
R.W. Brown ◽  
K. Gallagher ◽  
B.P. Kohn ◽  
...  
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Sediment Supply ◽  
Substantial Portion ◽  
Apatite Fission Track ◽  
Regional Modelling ◽  
Denudation Rate ◽  
Northern Margin ◽  
History Analysis ◽  
Gippsland Basin

The Emperor and Golden Beach Subgroups are becoming the focus of Gippsland Basin exploration, yet little is known about their composition and distribution. Regional modelling of over 400 apatite fission track analyses in the hinterland constrains the timing, magnitude and distribution of uplift and denudation and hence sediment supply to the basin. The study yielded regional maps through time of palaeotemperature, overburden, denudation rate and palaeotopography, with increasing assumptions and hence uncertainty.Regionally the >60,000 km3 of Strzelecki Group comprises ~90% volcanoclastic detritus and coal with only ~10% basement-derived sediment, but the northern margin of the basin, near Lakes Entrance, is likely to have a higher basement-derived portion resulting in better reservoirs. The basement-derived sediments are probably largely granitic as the Devonian granites were exposed during the Permo-Triassic Hunter-Bowen Orogeny. Regional mid-Cretaceous uplift resulted in increased denudation of basement, but inversion of the basin margins resulted in denudation of the onshore Strzelecki Group sediments. Emperor and Golden Beach Subgroup sediments deposited in the subsiding Central Graben were at least 50% basement-derived, again with higher quality reservoirs predicted near the Lakes Entrance area and poorer reservoirs near to Wilson’s Promontory. The Latrobe Group siliciclastics were at least 80% derived from basement with a substantial portion from northern Tasmania and the Furneaux Islands around 60-50 Ma.

FISSION TRACK THERMOCHRONOLOGY: APPLICATION TO CONTINENTAL RIFTING OF SOUTH-EASTERN AUSTRALIA

1991 ◽  
Vol 31 (1) ◽  
pp. 131 ◽  
Author(s):  
T. A. Dumitru ◽  
K. C. Hill ◽  
D. A. Coyle ◽  
I. R. Duddy ◽  
D. A. Foster ◽  
...  
Keyword(s):  
Thermal History ◽  
Fission Track ◽  
Apatite Fission Track ◽  
South Eastern ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Uplift And Erosion ◽  
Track Analysis ◽  
Plate Type ◽  
South Eastern Australia

Over the last five to ten years, apatite fission track analysis has developed into a sophisticated technique for studying the low-temperature thermal history of rocks. It has particular utility in oil exploration because its temperature range of sensitivity, about 20° to 125°C, overlaps the oil generation window. Whereas older fission track thermal history approaches relied solely on the sample fission track age, the new interpretive approaches use sample age, single grain age and track length data. They also emphasise the analysis of systematic variations in data patterns in sequences of samples, such as samples from various depths in a well. Laboratory study of the thermal annealing of fission tracks and compilation of fission track data from geological case studies has greatly improved our understanding of apatite fission track systematics, allowing considerably more detailed interpretations of thermal histories.Application of apatite fission track analysis to the rifted continental margins of south-eastern Australia shows that rifting and separation of Australia from Antarctica and the Lord Howe Rise were accompanied by at least 1.5-3 km of uplift and erosion along the Tasman Sea and Bass Strait coasts. Uplift and erosion were much less 100 km or so inland. This shows that the uplift of the south-eastern Australian margins was caused by the continental rifting process, the same process that initiated major subsidence in the sedimentary basins in Bass Strait. The consistent fission track data patterns around south-eastern Australia suggest a generally similar tectonic setting for the Tasman Sea and Bass Strait parts of the margin. Lister et al. (in press) propose that the Tasman part of the margin is an upper plate type of margin that formed above a west-dipping detachment zone. The fission track data suggest that the Bass Strait part of the margin may also be of upper plate type.

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