New constraints on the thermal history of North-East Greenland from apatite fission-track analysis

Thomson, Katie; Green, Paul F.; Whitham, Andrew G.; Price, S.J.; Underhill, John R.

doi:10.1130/0016-7606(1999)111<1054:ncotth>2.3.co;2

Cited by 41 publications

(67 citation statements)

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“…These AFT ages are consistent with rocks now at sea level being at temperatures between ∼ 110 and 70°C at ∼ 70 Ma (this temperature range approximates the apatite fission track partial annealing zone, where fission tracks are partially annealed and practically no He is retained). In addition, the short mean track lengths reported by Thomson et al (1999) for the same samples are consistent with the rocks having cooled from ∼ 70°C relatively recently. Furthermore, the AFT distribution in samples 2 and 3 record two cooling events, one from ∼ 105 to 95°C between ∼ 275 and 125 Ma and another from ∼ 95 to 60°C between 65 and 5 Ma.…”

Section: Constraints From Apatite Thermochronometrysupporting

confidence: 84%

“…AFT data published by Thomson et al (1999) for sea-level bedrock samples located near to profiles 19 and 21 are consistent with rapid cooling from temperatures of ∼ 70°C at ∼ 70 Ma. Specifically, AFT ages are much older for samples from Thomson et al (1999) that are closest to the base of profiles 19 and 21 than the respective He ages, namely for sample 3 (AFT age: 249.9 ± 15.7 Ma; ∼ 17 km from profile 19) and samples 2 and 6 (AFT ages: 103.5 ± 14.5 and 114.9 ± 15.6 Ma; both ∼ 2 km from profile 21).…”

Section: Constraints From Apatite Thermochronometrysupporting

confidence: 80%

“…Apatite fission track data from Traill Ø and Scoresby Land (Fig. 1a) indicate both early and late Tertiary cooling (Thomson et al, 1999;Hansen et al, 2001) but the latter appears to reflect localised magmatism associated with late Tertiary rifting at ∼ 30 Ma. The presence of ∼ 33 Ma intrusions at elevations up to 1300 m asl in the Traill Ø region (Noble et al, 1988) indicates some uplift during late Tertiary rifting; however, flat-lying plateau basalts at Milne Land indicate that the uplift did not affect Caledonian basement to the east of the post-Devonian main fault (Fig.…”

Section: Study Areamentioning

confidence: 95%

“…Specifically, AFT ages are much older for samples from Thomson et al (1999) that are closest to the base of profiles 19 and 21 than the respective He ages, namely for sample 3 (AFT age: 249.9 ± 15.7 Ma; ∼ 17 km from profile 19) and samples 2 and 6 (AFT ages: 103.5 ± 14.5 and 114.9 ± 15.6 Ma; both ∼ 2 km from profile 21). These AFT ages are consistent with rocks now at sea level being at temperatures between ∼ 110 and 70°C at ∼ 70 Ma (this temperature range approximates the apatite fission track partial annealing zone, where fission tracks are partially annealed and practically no He is retained).…”

Section: Constraints From Apatite Thermochronometrymentioning

confidence: 99%

See 3 more Smart Citations

A reassessment of the role of ice sheet glaciation in the long-term evolution of the East Greenland fjord region

et al. 2008

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Section: Constraints From Apatite Thermochronometrysupporting

confidence: 84%

Section: Constraints From Apatite Thermochronometrysupporting

confidence: 80%

Section: Study Areamentioning

confidence: 95%

Section: Constraints From Apatite Thermochronometrymentioning

confidence: 99%

See 2 more Smart Citations

A reassessment of the role of ice sheet glaciation in the long-term evolution of the East Greenland fjord region

et al. 2008

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“…Benthic δ 18 O values on Vøring Plateau indicate substantial deep water cooling at~11 Ma (Fronval and Jansen, 1996), and increased circum-Arctic IRD fluxes between 11.0 and 9.5 Ma (Schaeffer and Spiegler, 1986;Thiébault et al, 1989;Wolf and Thiede, 1991;Fronval and Jansen, 1996;Wolf-Welling et al, 1996;Helland and Holmes, 1997;Winkler et al, 2002) prove general cooling in the high northern latitudes. The timing of IRD events broadly corresponds to a major uplift phase on Greenland (Thomson et al, 1999;Japsen et al, 2006) suggesting a pivotal role in establishing the Greenland Ice Sheet during Late Miocene times, when pCO 2 stabilized at pre-industrial values (Pagani et al, 1999). Recently, Hegewald and Jokat (2013) showed that substantial relative global sea level fall since the middle Miocene, culminating in a lowstand at about the same time, is even more strongly expressed in the Arctic Ocean, and assumed a relation to the formation of ice sheets on the Northern Hemisphere.…”

Section: Glacial Inception In the Iceland Sea (~107-102 Ma)mentioning

confidence: 99%

Response of marine palynomorphs to Neogene climate cooling in the Iceland Sea (ODP Hole 907A)

Schreck

Méheust

Stein

et al. 2013

Marine Micropaleontology

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The present study on ODP Leg 151 Hole 907A combines a detailed analysis of marine palynomorphs (dinoflagellate cysts, prasinophytes, and acritarchs) and a low-resolution alkenone-based sea-surface temperature (SST) record for the interval between 14.5 and 2.5 Ma, and allows to investigate the relationship between palynomorph assemblages and the paleoenvironmental evolution of the Iceland Sea. A high marine productivity is indicated in the Middle Miocene, and palynomorphs and SSTs both mirror the subsequent long-term Neogene climate deterioration. The diverse Middle Miocene palynomorph assemblages clearly diminish towards the impoverished assemblages of the Late Pliocene; parallel with a somewhat gradual decrease of SSTs being as high as 20°C at~13.5 Ma to around 8°C at~3 Ma. Superimposed, palynomorph assemblages not only reflect Middle to Late Miocene climate variability partly coinciding with the short-lived global Miocene isotope events (Mi-events), but also the initiation of a proto-thermohaline circulation across the Middle Miocene Climate Transition, which led to increased meridionality in the Nordic Seas. Last occurrences of species cluster during three events in the Late Miocene to Early Pliocene and are ascribed to the progressive strengthening and freshening of the proto-East Greenland Current towards modern conditions. A significant high latitude cooling between 6.5 and 6 Ma is depicted by the supraregional "Decahedrella event" coeval with lowest Miocene productivity and a SST decline. In the Early Pliocene, a transient warming is accompanied by surface water stratification and increased productivity that likely reflects a high latitude response to the global biogenic bloom. The succeeding crash in palynomorph accumulation, and a subsequent interval virtually barren of marine palynomorphs may be attributed to enhanced bottom water oxygenation and substantial sea ice cover, and indicates that conditions seriously affecting marine productivity in the Iceland Sea were already established well before the marked expansion of the Greenland Ice Sheet at 3.3 Ma.

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Passive margins getting squeezed in the mantle convection vice

et al. 2013

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[1] Passive margins often exhibit uplift, exhumation, and tectonic inversion. We speculate that the compression in the lithosphere gradually increased during the Cenozoic, as seen in the number of mountain belts found at active margins during that period. Less clear is how that compression increase affects passive margins. In order to address this issue, we design a 2-D viscous numerical model wherein a lithospheric plate rests above a weaker mantle. It is driven by a mantle conveyor belt, alternatively excited by a lateral downwelling on one side, an upwelling on the other side, or both simultaneously. The lateral edges of the plate are either free or fixed, representing the cases of free convergence, and collision (or slab anchoring), respectively. This distinction changes the upper mechanical boundary condition for mantle circulation and thus, the stress field. Between these two regimes, the flow pattern transiently evolves from a free-slip convection mode toward a no-slip boundary condition above the upper mantle. In the second case, the lithosphere is highly stressed horizontally and deforms. For a constant total driving force, compression increases drastically at passive margins if upwellings are active. Conversely, if downwellings alone are activated, compression occurs at short distances from the trench and extension prevails elsewhere. These results are supported by Earth-like models that reveal the same pattern, where active upwellings are required to excite passive margins compression. Our results substantiate the idea that compression at passive margins is in response to the underlying mantle flow that is increasingly resisted by the Cenozoic collisions.

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New constraints on the thermal history of North-East Greenland from apatite fission-track analysis

Cited by 41 publications

References 0 publications

A reassessment of the role of ice sheet glaciation in the long-term evolution of the East Greenland fjord region

A reassessment of the role of ice sheet glaciation in the long-term evolution of the East Greenland fjord region

Response of marine palynomorphs to Neogene climate cooling in the Iceland Sea (ODP Hole 907A)

Passive margins getting squeezed in the mantle convection vice

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