 |
| Titel |
Post-orogenic evolution of the Northeast Greenland Caledonides |
| VerfasserIn |
Vivi Kathrine Pedersen, Søren Bom Nielsen, Kerry Gallagher |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045750
|
|
|
|
|
|
| Zusammenfassung |
| We present new apatite fission track (AFT) data from our study area in Northeast Greenland,
between 75.8-81oN. These data contain information on the spatial and temporal distribution
of exhumation in this remote area. We exploit this information by inverting for
time-temperature paths for each of our 31 samples, using AFT ages, fission track length
distributions, and measurements of weight percent chlorine.
In the onshore part of Northeast Greenland, between 75.8-81oN, accelerated
cooling occurred from Late Carboniferous – Triassic, followed by prolonged slow
cooling toward the present day. This could imply that late Paleozoic collapse and
rifting in the Caledonide mountain range focused in the now offshore Northeast
Greenland shelf, leaving the onshore crystalline basement relatively unaffected since
Triassic.
We investigate how these thermal histories convert to exhumation paths by
solving the steady-state heat-conduction equation in 1D, estimating the depth of
each sample back in time, continuously correcting crustal thickness (and hereby
allowing for changes in heat production). The resulting families of exhumation
solutions reflect the imposed uncertainties in the present day crustal thickness,
average heat production rate, present-day surface heat flow, and crustal thermal
conductivity.
The exhumation patterns from this area provide new information on the evolution of
passive margins in general. In particular our results show that the onshore regions of some
passive margins contain a record of exhumation over timescales much longer than the most
recent rifting episode. |
|
|
|
|
|
|