Dating of fault zone activity by apatite fission track and apatite (U-Th)/He thermochronometry: a case study from the Lavanttal fault system (Eastern Alps)

Terra Nova ◽  
2010 ◽  
pp. no-no ◽  
Author(s):  
A. Wölfler ◽  
W. Kurz ◽  
M. Danišík ◽  
R. Rabitsch
Keyword(s):  
Fault Zone ◽  
Fission Track ◽  
Eastern Alps ◽  
Fault System ◽  
Apatite Fission Track

Low-temperature thermochronology of fault zones

2020 ◽  
Author(s):  
Takahiro Tagami
Keyword(s):  
Low Temperature ◽  
Fault Zone ◽  
Fission Track ◽  
Thermal Sensitivity ◽  
Fault Zones ◽  
Fault System ◽  
Vein Formation ◽  
Fission Track Thermochronology ◽  
Mineral Vein ◽  
Host Rocks

<p>Thermal signatures as well as timing of fault motions can be constrained by thermochronological analyses of fault-zone rocks (e.g., Tagami, 2012, 2019).  Fault-zone materials suitable for such analyses are produced by tectocic and geochemical processes, such as (1) mechanical fragmentation of host rocks, grain-size reduction of fragments and recrystallization of grains to form mica and clay minerals, (2) secondary heating/melting of host rocks by frictional fault motions, and (3) mineral vein formation as a consequence of fluid advection associated with fault motions.  The geothermal structure of fault zones are primarily controlled by the following three factors: (a) regional geothermal structure around the fault zone that reflect background thermo-tectonic history of studied province, (b) frictional heating of wall rocks by fault motions and resultant heat transfer into surrounding rocks, and (c) thermal influences by hot fluid advection in and around the fault zone.  Geochronological/thermochronological methods widely applied in fault zones are K-Ar (<sup>40</sup>Ar/<sup>39</sup>Ar), fission-track (FT), and U-Th methods.  In addition, (U-Th)/He, OSL, TL and ESR methods are applied in some fault zones, in order to extract temporal information related to low temperature and/or recent fault activities.  Here I briefly review the thermal sensitivity of individual thermochronological systems, which basically controls the response of each method against faulting processes.  Then, the thermal sensitivity of FTs is highlighted, with a particular focus on the thermal processes characteristic to fault zones, i.e., flash and hydrothermal heating.  On these basis, representative examples as well as key issues, including sampling strategy, are presented to make thermochronological analysis of fault-zone materials, such as fault gouges, pseudotachylytes and mylonites, along with geological, geomorphological and seismological implications.  Finally, the thermochronological analyses of the Nojima fault are overviewed, as an example of multidisciplinary investigations of an active seismogenic fault system.</p><p> </p><p>References:</p><ol><li>Tagami, 2012. Thermochronological investigation of fault zones. Tectonophys., 538-540, 67-85, doi:10.1016/j.tecto.2012.01.032.</li> <li>Tagami, 2019. Application of fission track thermochronology to analyze fault zone activity. Eds. M. G. Malusa, P. G. Fitzgerald, Fission track thermochronology and its application to geology, 393pp, 221-233, doi: 10.1007/978-3-319-89421-8_12.</li> </ol>

The Miocene plutonic event of the Patagonian Batholith at 44° 30′ S: thermochronological and geobarometric evidence for melting of a rapidly exhumed lower crust

2000 ◽  
Vol 91 (1-2) ◽  
pp. 169-179 ◽  
Author(s):  
M. A. Parada ◽  
A. Lahsen ◽  
C. Palacios
Keyword(s):  
Late Miocene ◽  
Lower Crust ◽  
Fission Track ◽  
Strike Slip ◽  
Fault System ◽  
Apatite Fission Track ◽  
Axial Zone ◽  
Exhumation Rates ◽  
Fission Track Ages ◽  
Host Rocks

The Patagonian Batholith was formed by numerous plutonic events that took place between the Jurassic and the Miocene. North of 47° S, the youngest plutons occupy the axial zone adjacent to the Liquiñe-Ofqui Fault Zone, which is a major intra-arc strike-slip fault system active since the Miocene. The Queulat Complex, located at 44° 30′ S, includes two Miocene plutonic units: the Early Miocene Queulat diorite (QD) and the Late Miocene Puerto Cisnes granite (PCG). The QD includes hornblende + clinopyroxene diorites and tonalites, whereas the PCG includes slightly peraluminous garnet ± sillimanite granites and granodiorites.Eleven mineral Ar–Ar ages and three apatite fission track ages were obtained from the Queulat Complex and surrounding host rocks. Hornblende and biotite Ar–Ar ages of c. 16-18 Ma and 9-10 Ma, respectively, were obtained for the QD. The youngest ages of the QD are similar to the age of emplacement of the PCG as previously determined. Ar–Ar ages for muscovites and biotites of 6·6 ± 0·3 Ma and 5·6 ± 0·1 Ma, respectively, were obtained for the PCG. Biotites and muscovites from mylonites and pelitic hornfelses adjacent to the PCG yielded Ar—Ar ages between 5·1 Ma and 5·5 Ma. The apatite fission track ages of the QD and PCG overlap within the error margin (2•2 ± 1·1-3·3 ± 1·4 Ma).The Al-in-hornblende geobarometer yielded pressures for the QD emplacement equivalent to depths in the 19-24 km range, which is substantially higher than the 10 km depth estimated previously for the PCG emplacement. Exhumation rates (v) up to 2·0mm/yr were calculated for the time elapsed between the QD and PCG emplacements. A v value of 1·0mm/yr was calculated for the PCG subsequent to its emplacement. Using the silica—Ca-tschermak-anorthite geobarometer, we estimate the QD magma generation to be at c. 33 km, which is similar to the current crustal thickness. Melting of mafic and metapelitic lower crust was possible at > 30km depth during a period when v was between 1·0mm/yr and 2·0mm/yr.

Fault zone development and strain partitioning in an extensional strike-slip duplex: A case study from the Mesozoic Atacama fault system, Northern Chile

2005 ◽  
Vol 400 (1-4) ◽  
pp. 105-125 ◽  
Author(s):  
J. Cembrano ◽  
G. González ◽  
G. Arancibia ◽  
I. Ahumada ◽  
V. Olivares ◽  
...  
Keyword(s):  
Fault Zone ◽  
Strike Slip ◽  
Fault System ◽  
Northern Chile ◽  
Strain Partitioning ◽  
Zone Development ◽  
Atacama Fault System

Cretaceous−Cenozoic history of the southern Tan-Lu fault zone: apatite fission-track and structural constraints from the Dabie Shan (eastern China)

2002 ◽  
Vol 359 (3-4) ◽  
pp. 225-253 ◽  
Author(s):  
J.C. Grimmer ◽  
R. Jonckheere ◽  
E. Enkelmann ◽  
L. Ratschbacher ◽  
B.R. Hacker ◽  
...  
Keyword(s):  
Fault Zone ◽  
Fission Track ◽  
Eastern China ◽  
Structural Constraints ◽  
Apatite Fission Track ◽  
Dabie Shan ◽  
History Of

scholarly journals CENOZOIC TECTONIC EVOLUTION OF THE EASTERN ALPS – A RECONSTRUCTION BASED ON 40AR/39AR WHITE MICA, ZIRCON AND APATITE FISSION TRACK, AND APATITE (U/Th)-He THERMOCHRONOLOGY

2017 ◽  
Vol 43 (1) ◽  
pp. 299
Author(s):  
W. Kurz ◽  
A. Wölfler ◽  
R. Handler
Keyword(s):  
Tectonic Evolution ◽  
Fission Track ◽  
Eastern Alps ◽  
White Mica ◽  
Fault Zones ◽  
Apatite Fission Track ◽  
Major Fault ◽  
Fission Track Ages ◽  
Fault Gouges ◽  
Host Rocks

The Cenozoic tectonic evolution of the Eastern Alps is defined by nappe assembly within the Penninic and Subpenninic units and their subsequent exhumation. The units above, however, are affected by extension and related faulting. By applying distinct thermochronological methods with closure temperatures ranging from ~450° to ~40°C we reveal the thermochronological evolution of the eastern part of the Eastern Alps. 40Ar/39Ar dating on white mica, zircon and apatite fission track, and apatite U/Th-He thermochronology were carried out within distinct tectonic units (Penninic vs. Austroalpine) and on host rocks and fault- related rocks (cataclasites and fault gouges) along major fault zones. We use particularly the ability of fission tracks to record the thermal history as a measure of heat transfer in fault zones, causing measurable changes of fission track ages and track lengths. Additionally, these studies will provide a general cooling and exhumation history of fault zones and adjacentcrustal blocks.

Thermo-tectonic imaging of the Afro-Arabian Rift System

2020 ◽  
Author(s):  
Samuel Boone ◽  
Fabian Kohlmann ◽  
Maria-Laura Balestrieri ◽  
Malcolm McMillan ◽  
Barry Kohn ◽  
...  
Keyword(s):  
Low Temperature ◽  
Red Sea ◽  
Fission Track ◽  
Normal Fault ◽  
Eastern Africa ◽  
Fault System ◽  
Rift System ◽  
Gulf Of Aden ◽  
Apatite Fission Track ◽  
Continental Scale

<p>Low-temperature thermochronology has long been utilised in the Afro-Arabian Rift System (AARS) to examine exhumation cooling histories of normal fault footwalls and elucidate rifting chronologies where datable syn-rift strata and/or markers are absent. In particular, apatite fission track (AFT) and (U-Th)/He (AHe) analyses have constrained the timing and rate of rift-related, upper crustal thermal perturbations between ~30 and 120 °C (up to ~5 km depth). In turn, these provide insights into the spatio-temporal evolution of individual rift basins, morphotectonic rift shoulder development, normal fault system growth and, in some cases, the thermal influence of igneous intrusions and circulation of hot fluids. However, the relatively limited number of samples and confined areas generally involved in individual case studies have precluded insights into longer wavelength tectonic and geodynamic phenomena, such as regional denudation trends and the growth of topography due to plume impingement.</p><p>Here, we present a synthesis of >2000 apatite fission track (AFT) and ~1000 (U-Th)/He (AHe) analyses from the Eocene-Recent AARS collated using LithoSurfer, a new cloud-based geoscience data platform. This continental-scale low-temperature thermochronology synthesis, the first of its kind in Africa, provides novel insights into the upper crustal evolution of the AARS that were previously difficult to decipher from an otherwise cumbersome and intractably large dataset. The data record a series of pronounced episodes of upper crustal cooling related to the development of the Red Sea, Gulf of Aden and East African Rift System (EARS). They also provide insights into the inherited tectono-thermal histories of these regions which controlled the spatial and temporal distribution of subsequent extensional strain.</p><p>Thermochronology data trends along the AARS reflect a combination of rift maturity, structural geometry and geothermal regime, intrinsically linked to lithospheric architecture and magmatic activity. These relationships are best illustrated by contrasting the upper crustal thermal evolution of different AARS segments of varying age and complexity: for example, between the nascent Okavango, mature Ethiopian and evolved Red Sea rifts, wide (e.g. Turkana Depression) versus narrow (e.g. Main Ethiopian Rift) zones of deformation, between areas of transtensional (Dead Sea Transform), oblique (e.g. Gulf of Aden) and sub-orthogonal rifting (e.g. Malawi Rift), and the magmatic eastern versus amagmatic western branches of the EARS.</p><p>A regional interpolation of standardised thermal history models generated from the mined AFT, AHe and, in some cases, vitrinite reflectance data yield Mesozoic-recent heat maps, extrapolated to produce paleo-denudation and burial histories for eastern Africa and Arabia. Integrating these thermotectonic images with other regional datasets allows for the interrelationship between tectonic and dynamic topography development, the denudation history of the land surface, and sediment transport and deposition to be explored in new ways.</p><p> </p>

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