MAGNETIC PROPERTIES OF PALAEOZOIC AND MESOZOIC SEDIMENTARY ROCKS FROM THE BARENTS SEA

The main aims of the project ‘OSRAM II - Origin of Sed-iment-Related AeroMagnetics II’ are to characterise and interpret variations in magnetic susceptibility in the Palaeozoic and Mesozoic sedimentary successions offshore eastern Finnmark and to identify the miner-alogical source of the magnetism in these sediments.

The project is a multi-client spec-project with a fixed price, organised in collaboration between NGU and SIN-TEF Petroleum Research.

BACKGROUND

Recent aeromagnetic surveys in the Nordkapp Basin have revealed distinct negative magnetic anomalies caused by the contrast in magnetic properties between the salt and the adjacent sedimentary sequences. The incorporation of magnetic susceptibility will lead to more precise quantitative analyses and will reduce the inherent ambiguity in the interpretation of the aero- magnetic data. The value of susceptibility measure-ments on shallow stratigraphic cores from sedimenta-ry rocks has been demonstrated in a previous project (OSRAM, 1996) on material from the North Sea and the Norwegian Sea.

The susceptibility measurements are combined with lithological and mineralogical characterisation to im-prove interpretation and allow prediction of the mag-netic properties in similar rocks.

A total of about 1730 m of cores from the Svalis Dome, Nordkapp Basin and Finnmark East, collected by SINTEF Petroleum Research, will be measured with respect to magnetic susceptibility.

OSRAM II – ORIGIN OF SEDIMENT-RELATED AEROMAGNETICS II

INFOAPRIL 2015

PLEASE VISITWWW.NGU.NO FOR MORE INFO

ODLEIV OLESEN Team Leader, Continental Shelf Geophysics

odleiv.olesen@ngu.no Tel: +47 990 91 743

ATLE MØRK SINTEF Petroleum Research

NO-7465 Trondheimatle.mork@sintef.no Tel: +47 415 14 490

ORDERING:

Price for late participants:

168,000 NOK

TORLEIF LAURITSENSenior Engineer, Continental Shelf Geophysics

torleif.lauritsen@ngu.noTel: +47 73 90 44 63

SAMPLE MATERIALS

The approximately 1730 m of core include representative samples from all stratigraphic units within the Palaeozoic and Mesozoic successions in the eastern part of the Norwegian Barents Sea (i.e. the Svalis Dome, Nordkapp Basin and the Finnmark East area).

METHODS

We have applied the Bartington MS2 Susceptibility instrument with digital transfer to a laptop computer. Measurements were carried out every 0.5 m. The instrument was calibrated using reference samples with known susceptibility.

DELIVERABLES

The project results are presented in a report that includes all data as well as discussions and conclusions. The magnetic properties are discussed in relation to mineralogy, lithology and stratigraphy and the properties are compared between the different areas. The data are presented as tables, susceptibility logs and as a compilation figure of magnetic properties in a stratigraphic and geographic framework. Digital data are delivered on a CD-ROM.

SPONSORS

Chevron, DEA, GdF Suez, Statoil.

Example of demonstration cuts from the SINTEF Petroleum Research cores.

Bartington MS2 susceptibility instrument.

NGU - GEOLOGICAL SURVEY OF NORWAY

CONTACT ADDRESS

PO Box 6315 Sluppen NO-7491 Trondheim Phone: +47 73 90 40 00

VISITING ADRESS

Leiv Eirikssons vei 39, TrondheimE-mail: ngu@ngu.nowww.ngu.no/continental_shelf_geophysics

SOCIAL MEDIA

Facebook /Norges.geologiske.undersokelseTwitter /nguwebYoutube /nguweb