The magnetism of a glacial aeolianite sequence from Lanzarote (Canary Islands): coupling between luvic calcisol formation and Saharan dust trapping processes during wet deposition events off northwestern Sahara

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Glacial Climate, Loess Magnetism, Low-Temperature Magnetic Behaviour, Magnetic Susceptibility, Saharan Dust, Titanomagnetite

Scientific paper

In order to better document the climatic origin of pedogenized loess deposits west of Sahara, rock-magnetic measurements were performed on a Last Glacial coastal sand sequence from La Mala (LM) quarry (Lanzarote, Canary Islands) containing six interbedded loess-palaeosol units. Hysteresis and susceptibility data point to a coarse-grained magnetic enhancement in the coastal sand, which contrasts with the superparamagnetic (SP) to pseudo-single domain (PSD) behaviour of the Saharan loess and palaeosol. High- and low-temperature experiments show that oxidized titanomagnetite contributions dominate in the sand, while fine-grained (SP to PSD) iron oxidation products such as maghemite and goethite are evidenced in the Saharan loess/palaeosol units. At room temperature, the detrital PSD-multidomain titanomagnetite contribution of local origin is tentatively estimated from the AC-field dependence of magnetic susceptibility. Surface oxidation of detrital spinel grains and authigenesis of fine-grained iron oxides (including SP goethite) are proposed to explain the magnetic properties of the primarily fine, Saharan-dust-bearing material.
The dry, local climate of the present-day and Late Holocene means that loess deposits are not preserved. The six pedogenized loess units, however, point to dust trapping under semi-arid, wetter conditions, probably illustrating periods of reduced latitudinal temperature gradients and climate variability of the North Atlantic climate, respectively. These findings suggest that both the Canary palaeosol and its content of (ultra)fine iron oxide might be constrained by (wet) deposition and trapping of fine Saharan dust.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The magnetism of a glacial aeolianite sequence from Lanzarote (Canary Islands): coupling between luvic calcisol formation and Saharan dust trapping processes during wet deposition events off northwestern Sahara does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The magnetism of a glacial aeolianite sequence from Lanzarote (Canary Islands): coupling between luvic calcisol formation and Saharan dust trapping processes during wet deposition events off northwestern Sahara, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The magnetism of a glacial aeolianite sequence from Lanzarote (Canary Islands): coupling between luvic calcisol formation and Saharan dust trapping processes during wet deposition events off northwestern Sahara will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-895962

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.