Natural long-term annealing of the zircon fission-track system in Vienna Basin deep borehole samples: constraints upon the partial annealing zone and closure temperature

Below the Potamos extensional detachment fault exposed in northern Kythera, the phyllite-quartzite unit (PQU) shows very consistent zircon FT cooling ages of c.11 Ma reflecting the time just after the rapid exhumation through the brittle-ductile transition. In contrast, a wide range of Mesozoic and some Paleozoic zircon FT cooling ages from Eocene-Oligocene Tripolis and Pindos flysch sandstones from above the detachment reflect sedimentary source ages. Early Miocene apatite fissiontrack cooling ages characterize the flysch sandstones, and show that early Miocene exhumation affected rocks above the detachment. The thermotectonic evolution of the flysch of Tripolis and Pindos units within the rocks above the Potamos detachment on Kythera is reconstructed using zircon and apatite fission-track (FT) thermochronology. The apatite FT data provide evidence for a burial depth of at least 6km for the samples, which were reset. Burial was not deeper than 11km, since the zircon fission-track system in the same rocks was not reset. The exposed rocks of Tripolis and Pindos flysch on Kythera represent part of an accretionary wedge with a burial shortly after deposition in or near the subduction trench, and a cooling history due to exhumation of the flysch in the early Miocene. The subsequent Mid-Late Miocene exhumation of the PQU unit follows from beneath the (mostly carbonate) Tripolis and Pindos sedimentary rocks.

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Zircon (U-Th)/He Closure Temperature Lower than Apatite Ther-Mochronometric Systems: Reconciliation of a Paradox

10.20944/preprints202112.0197.v1 ◽

2021 ◽

Author(s):

Benjamin Gilles Gérard ◽

Xavier Robert ◽

Cécile Gautheron ◽

Djordje Grujic ◽

Laurence Audin ◽

...

Keyword(s):

Low Dose ◽

Fission Track ◽

Damage Model ◽

Closure Temperature ◽

Machu Picchu ◽

Zircon Fission Track ◽

Dose Ranging ◽

Fission Track Ages ◽

The One ◽

Very High

We present here seven new zircon (U-Th)/He (ZHe) ages and three new zircon fission track ages (ZFT) analyzed from an age-elevation profile (Machu Picchu, Peru). ZFT data present older ages in comparison with the other thermochronological data, whereas the ZHe data interestingly present similar ages than the ones obtained with apatite (U-Th)/He (AHe). It has been proposed that He retention in zircon is linked to the damage dose, with an evolution of the closure-temperature from low values associated to low α-dose (<1016 α/g), subsequently increasing before decreasing again at very high α-dose (>1018 α /g). Studies have been focused on the He diffusion behavior at high α-dose, but little is known at low dose. We propose that the ZHe closure temperature at α-dose ranging from 0.6×1015 to 4×1016 α/g is in the range of ~60-80°C. This value is lower than the one proposed in the current damage model ZRDAAM and demonstrates that the ZHe and AHe methods could have similar closure temperatures at low α-dose (i.e. similar ages). These new data strengthen our previous geological conclusions and even highlight an about twice more important cooling rate than the one deduced from AHe and apatite fission-track data alone registered at Machu Picchu.

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Two pulse intrusive events of the Pliocene Tanigawa-dake granites revealed from zircon U–Pb dating

Earth Planets and Space ◽

10.1186/s40623-021-01556-4 ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Saki Minami ◽

Mitsuhiro Nagata ◽

Shigeru Sueoka ◽

Shoma Fukuda ◽

Yuya Kajita ◽

...

Keyword(s):

Fission Track ◽

Closure Temperature ◽

Error Range ◽

Zircon Fission Track ◽

Northeast Japan Arc ◽

Fission Track Ages

AbstractWe performed zircon U–Pb dating on the Pliocene Tanigawa-dake granites (Makihata and Tanigawa bodies) and the Cretaceous Minakami quartzdiorite, Northeast Japan Arc. Concordia ages were estimated to be 3.95 ± 0.11 Ma (± 2 sigma) for the Makihata body, 3.18 ± 0.13 Ma and 3.32 ± 0.15 Ma for the Tanigawa body, and 109.4 ± 2.2 Ma for the Minakami quartzdiorite. The Minakami quartzdiorite is possibly correlated to the bedrock in the Ashio belt because the age of the Minakami quartzdiorite is consistent with the zircon U–Pb ages of the earliest Tadamigawa granites (107–62 Ma) which are distributed to the northeast of the Tanigawa-dake region and belong to the Ashio belt. All the zircon U–Pb ages of the Tanigawa-dake granites are older than the previously reported cooling ages, i.e., K–Ar ages and zircon fission-track ages, being consistent with their difference in closure temperature. On the basis of these results, we concluded that the intrusive ages of the Tanigawa-dake granites are ~ 4–3 Ma, which are among the youngest exposed plutons on Earth. The U–Pb ages of the Makihata body and the Tanigawa body are different significantly in the 2 sigma error range. Thus, the Tanigawa body intruded later than the Makihata body by ~ 0.7 Myr. Graphical Abstract

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Positioning the titanite fission-track partial annealing zone

Chemical Geology ◽

10.1016/s0009-2541(98)00041-2 ◽

1998 ◽

Vol 149 (1-2) ◽

pp. 117-125 ◽

Cited By ~ 45

Author(s):

D.A. Coyle ◽

G.A. Wagner

Keyword(s):

Fission Track ◽

Annealing Zone ◽

Partial Annealing

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Evidence for post-early Eocene tectonic activity in southeastern Ireland

Geological Magazine ◽

10.1017/s0016756802007240 ◽

2003 ◽

Vol 140 (2) ◽

pp. 101-118 ◽

Cited By ~ 11

Author(s):

M. J. M. CUNNINGHAM ◽

A. L. DENSMORE ◽

P. A. ALLEN ◽

W. E. A. PHILLIPS ◽

S. D. BENNETT ◽

...

Keyword(s):

Fission Track ◽

Tectonic Activity ◽

Early Eocene ◽

Apatite Fission Track ◽

Annealing Zone ◽

Domain Boundaries ◽

Vertical Displacements ◽

Spatial Domains ◽

Thermal Histories ◽

Partial Annealing

The role played by Cenozoic deformation in denudation and landscape development in Ireland has historically been difficult to assess because of the lack of widespread pre-glacial Cenozoic deposits onshore. Here we combine analysis of apatite fission-track data and geomorphic observations to place constraints on the timing, kinematics and magnitude of onshore deformation in southeastern Ireland. Relationships between apatite fission-track central age and elevation for samples from the Wicklow and Blackstairs Mountains and Tullow Lowland suggest that these rocks record an exhumed apatite partial annealing zone, which after cooling was dismembered by differential vertical displacements of up to several hundred metres. We use inverted models of sample thermal history to show that samples across the region experienced very similar thermal histories up to and including a cooling event in late Paleocene or early Eocene time. This effectively rules out strongly spatially heterogeneous denudation, and implies that differential rock uplift occurred in post-early Eocene time. The central age–elevation relationships define at least three spatial domains with internally consistent apatite fission-track data, separated by known faults or topographic escarpments. Geomorphic analysis of these structures shows that patterns of catchment incision and sinuosity, as well as the presence of antecedent drainage, are best explained by differential vertical displacements at or near the domain boundaries. The kinematics and magnitudes of these displacements are consistent with those implied by the apatite fission-track results, and are compatible with other examples of known Cenozoic deformation from Ireland and the adjacent continental margin.

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Closure temperature implications of concordant 40Ar/39Ar potassium feldspar and zircon fission-track ages from high-grade terranes

Nuclear Tracks and Radiation Measurements (1982) ◽

10.1016/0735-245x(85)90170-x ◽

1985 ◽

Vol 10 (3) ◽

pp. 441

Author(s):

PeterK. Zeitler

Keyword(s):

Fission Track ◽

Potassium Feldspar ◽

Closure Temperature ◽

High Grade ◽

Zircon Fission Track ◽

Fission Track Ages

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Evolution of a low-relief landscape in the Eastern Alps constrained by low-temperature thermochronology and cosmogenic nuclides

10.5194/egusphere-egu2020-4632 ◽

2020 ◽

Author(s):

Andreas Wölfler ◽

Sebastian Reimers ◽

Andrea Hampel ◽

Christoph Glotzbach ◽

István Dunkl

Keyword(s):

Low Temperature ◽

Fission Track ◽

Eastern Alps ◽

Cosmogenic Nuclides ◽

Near Surface ◽

Erosion Rates ◽

Exposure Dating ◽

Zircon Fission Track ◽

Exposure Ages

The relief history of mountain belts is strongly influenced by the interplay of tectonics and surface processes, which both shape Earth&#180;s landscapes. In this context, the quantification of the rates of long-term and short-term processes is key for understanding landscape evolution and requires the application of methods that integrate over different timescales. In this study, we apply low-temperature thermochronology and cosmogenic nuclides to quantify the geological and geomorphic evolution of an elevated low-relief landscape in the Eastern Alps, the so-called Nock Mountains, which are situated to the east of the Tauern Window. The low-temperature thermochronological data yield zircon fission track and zircon (U-Th)/He cooling ages of 93.4&#177;12.9 and 77.8&#177;7.8 Ma, respectively, which we interpret to reflect late Cretaceous cooling after Eo-Alpine metamorphism. Apatite fission track and (U-Th)/He ages are significant younger and range from 36.8 to 31.3 Ma. Time-temperature history modelling of the cooling ages suggests enhanced cooling in the Eocene followed by thermal stagnation. Thus, the rocks of the study area have been in near surface position (2-3 km) since the Late Eocene. Enhanced cooling in the Eocene is probably related to an increasing relief due to shortening, folding and thrusting in the Eastern Alps triggered by the onset of collision between the European margin and the Adriatic microplate. Under the assumption that rock exhumation occurred solely by erosion, the long-term average erosion rate derived from the thermochronological data is ~50-90 mm/kyr. Catchment-wide erosion rates derived from cosmogenic 10Be in river sediments&#160; range from 83&#177;7 to 205&#177;18 mm/kyr and hence are lower than in other parts of the Alps. As the 10Be-derived erosion rates and the long-term rates derived from thermochronology agree despite the different timescales over which the two methods integrate, our new data suggest that erosion rates did not change significantly over the last ~40 Ma. This is remarkable because within this time span numerous tectonic processes and glacial-interglacial cycles affected the study area. To investigate the deglaciation history after the Last Glacial Maximum in the Nock Mountains, we sampled glacially polished quartz veins for 10Be exposure dating. The first four exposure ages obtained so far cluster between 14.5&#177;1.4 and 16.8&#177;1.6 ka. We interpret these ages as the record the retreat of the ice cover in the study area shortly after the Oldest Dryas stadial.

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