Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists: an example from Tampere Schist Belt, Finland

TY - ABST

T1 - Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists: an example from Tampere Schist Belt, Finland

AU - Kalliomäki, Henrik

AU - Torvela, Taija

AU - Moreau, Julien

AU - Kähkönen, Yrjö

PY - 2014/9

Y1 - 2014/9

N2 - We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic relationship between the interpreted palaeothrust and the sulphide-bearing schist horizons in the study area. On a more general note, the results imply that currently subvertical mineralized shear zones may have originally been gently dipping, further suggesting that the mineralized fluids may not necessarily have been sourced from great depths (i.e. from deep within the basement).

AB - We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic relationship between the interpreted palaeothrust and the sulphide-bearing schist horizons in the study area. On a more general note, the results imply that currently subvertical mineralized shear zones may have originally been gently dipping, further suggesting that the mineralized fluids may not necessarily have been sourced from great depths (i.e. from deep within the basement).

M3 - Conference abstract for conference

T2 - 31st Nordic Geological Winter Meeting

Y2 - 8 January 2014 through 10 January 2014

ER -