Recycling a Sedimentary Basin - Evidence From Microscopic Fluid Inclusions in Detrital Quartz

Abstract

Recycling a Sedimentary Basin - Evidence from Microscopic Fluid Inclusions in Detrital Quartz

Beyene Girma Haile¹, Helge Hellevang^1,2, Tore Grane Klausen³, Snorre Olaussen², Christian Haug Eide³, William Helland-Hansen³

¹Department of Geosciences, University of Oslo, P.O.BOX 1047, Blindern, NO0316 Oslo, Norway

²The University Centre in Svalbard (UNIS), P.O.BOX 156, 9171 Longyearbyen, Norway

³Department of Earth Science, University of Bergen, Allegaten 41, 5007 Bergen, Norway

Corresponding author: b.g. [email protected]

Abstract: Sedimentary basins that contain recycled sediments delivered from older and uplifted basins create important complications for source-to-sink analysis and robust interpretation of geochronological data. In this study, we show how microscopic fluid inclusions in detrital quartz can be used to distinguish between recycled and first-generation sediments, thus solving these problems. A mixture of first-generation and recycled sediments have been deposited in the Upper Triassic to Lower Jurassic sediments at Wilhelmøya (Svalbard). Detrital quartz grains with dust rims and fluid inclusions and sometimes-abraded authigenic growth indicate earlier deep burial. The aim of this study is therefore to use these fluid inclusion data to constrain sediment recycling in the larger Permain-Jurassic Barents Sea system. The sediments were examined using cathodoluminescence (CL)-scanning electron microscopy and optical microscopy. Authigenic quartz displayed very low CL intensity compared to the detrital quartz grains. The earlier deep burial is unequivocally supported by the homogenization temperature (T_h) measurements, which suggests that sediments have been subjected to a temperature of 130 °C. The quartz overgrowth T_h values undoubtedly depart from the normal burial history of the sediments in the study area. The most likely source for these sediments is the area around the present-day Novaya Zemlya orogen, which experienced incipient uplift at the time and re-exposure of Triassic sediments. Results of this study will have implications to constrain source area configuration and long-term sediment dispersal patterns in linked orogeny and foreland basin systems.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019