Data Publication

Paleomagnetic and paleointensity data from two Cambrian igneous sequences: 505 Ma Bourinot volcanic rocks of Cape Breton Island, Nova Scotia, Canada, and 525 Ma Itabaiana mafic dyke swarm of northeastern Brazil

Lloyd, Simon | Hopkins, Rebecca

NERC EDS National Geoscience Data Centre

(2026)

Descriptions

The dataset contains experimental data from two Cambrian igneous sequences: the approximately 505 Ma Bourinot volcanic rocks of Cape Breton Island, Nova Scotia, Canada, and the approximately 525 Ma Itabaiana mafic dyke swarm of northeastern Brazil. It includes specimen-level paleointensity measurements, paleomagnetic directional data, experiment-step references and file-level metadata. Bourinot samples were analysed using thermal Thellier paleointensity experiments. Itabaiana samples were analysed using thermal and microwave Thellier, modified Shaw, and continuous Triaxe/Wilson methods. The deposited files include upload-ready data for Paleomagnetism.org and Paleointensity.org and supporting files needed to interpret the laboratory treatment steps and directional measurements. These data provide new constraints on Cambrian geomagnetic field strength and were used to show that weak field conditions persisted for tens of millions of years after the Cambrian radiation. The data support the manuscript “Earth’s magnetic field remained weak for 40 million years after the Cambrian radiation”

Keywords

MSL enriched keywords
Phanerozoic
Paleozoic
Cambrian
Apparatus
natural remanent magnetisation measurement
vibrating sample magnetometer (VSM)
Triaxe
laboratory induced remanent magnetisation measurement
thermoremanent magnetiser (TRM)
Triaxe
demagnetiser
thermal demagnetiser
Triaxe
Measured property
paleointensity
Inferred behavior
natural remanent magnetisation processing
relative paleointensity
MSL vocabulary keywords corresponding to originally assigned keywords
Cambrian
Triaxe
Triaxe
Triaxe
Originally assigned keywords
Palaeointensity
palaeomagnetism
geomagnetic secular variation
geomagnetic field intensity
weak geomagnetic field
Cambrian
geodynamo
inner core nucleation
geomagnetic reversals
Bourinot volcanics
thermal Thellier
microwave palaeointensity
Shaw method
Triaxe
Wilson method
rock magentism

Metadata


MSL enriched sub domains

paleomagnetism

Source

https://www2.bgs.ac.uk/nationalgeosciencedatacentre/citedData/catalogue/34859b8e-0619-4d00-a55d-ff5bc7379a54.html

Source publisher

NERC EDS National Geoscience Data Centre

DOI

10.5285/34859b8e-0619-4d00-a55d-ff5bc7379a54

Creators

Lloyd, Simon
Personal
University of Liverpool
Hopkins, Rebecca
Personal
University of Liverpool

Citation

Lloyd, S., & Hopkins, R. (2026). Paleomagnetic and paleointensity data from two Cambrian igneous sequences: 505 Ma Bourinot volcanic rocks of Cape Breton Island, Nova Scotia, Canada, and 525 Ma Itabaiana mafic dyke swarm of northeastern Brazil [Dataset]. NERC EDS National Geoscience Data Centre. https://doi.org/10.5285/34859B8E-0619-4D00-A55D-FF5BC7379A54


Dates

Available 2026-07-17

Language

- no language entry found -


Funding References

Funder Name Natural Environment Research Council
Funder Identifier https://doi.org/10.13039/501100000270
Award Number NE/X014142/1
Award Title Palaeomagnetic field behaviour in the Palaeozoic and the hunt for inner core birth

Locations


Geo location(s)

Cape Breton Island, Nova Scotia, Canada

northeastern Brazil