How to Detect and Correct a Compaction - shallowed Inclination - Paleomagnetism of Sedimentary Rocks: Process and Interpretation - page 54

Table 5.1 Anisotropy - based inclination - shallowing correction
Formation and age Locality Magnetic

mineralogy

Magnetic
anisotropy

Flattening factor,
f

Reference

DSDP cores, Cretaceous Pacifi c Ocean Magnetite ARM 0.53 Hodych et al . (1999)

Marine cores, Recent Atlantic Ocean Magnetite ARM - Collombat et al . (1993)

Pigeon Point Formation,
Cretaceous

California Magnetite ARM 0.7 Kodama & Davi (1995)

Nacimiento Formation,
Paleocene

New Mexico Titano-

hematite

ARM 0.84 Kodama (1997)

Point Loma and Ladd
Formation

S. California Magnetite ARM 0.56 (PL)

0.65 (Ld)

Tan & Kodama (1998)

Cretaceous rudist-
bearing rocks

California Magnetite ARM - Kodama & Ward

(2001)

Nanaimo Group,
Cretaceous

Vancouver
Island, Brit Col.

Magnetite ARM 0.7 Kim & Kodama (2004)

Perforada Formation,
Cretaceous

Baja California,
Mexico

Magnetite ARM 0.6 Vaughn et al . (2005)

Glenshaw Formation
Carboniferous

Pennsylvania Magnetite ARM 0.65 Kodama (2009)

Deer Lake Formation,
Carboniferous

Newfoundland
Canada

Magnetite ARM 0.54 Bilardello & Kodama

(2010b)

Mauch Chunk Formation,
Carboniferous

Pennsylvania Hematite AMS-chemical 0.22 Tan & Kodama (2002)

Kapusaliang Formation,
Cretaceous

Western China Hematite AMS-chemical 0.3 Tan et al . (2003)

Shepody and Maringouin
Formation, Carboniferous

Nova Scotia Hematite IRM-high fi eld 0.64 (Shep)

0.83 (Mar)

Bilardello & Kodama
(2009b)

Mauch Chunk Formation,
Carboniferous

Pennsylvania Hematite IRM-high fi eld 0.49 Bilardello & Kodama

(2010a)

Cretaceous red beds SE China Hematite IRM-45° 0.82 Wang & Yang (2007)

Yezo Supergroup,
Cretaceous

Japan Magnetite IRM-45° 0.71 Tamaki et al . (2008)

Elatina and Nucaleena
Formation,
Neoproterozoic

Australia Hematite IRM-parallel and

perpendicular to
bedding

0.92 (E arenites)
0.97 (E rhythmites)
0.98 (N)

Schmidt et al . (2009)

crystallography of the hematite however controls the
shape of the nano-particles of hematite to be plate-like
and the basal plane magnetization then typically lies in
the plane of the hematite plate-like crystals. Tan &
Kodama (2003) therefore modifi ed the Jackson et al .
(1991) approach for an orientation distribution of
magnetic grains that are disk-shaped with their mag-
netizations lying in the plane of the disks. This resulted

in a new expression for f , the fl attening in the tan I c =
f tan I 0 equation used for the anisotropy correction:

( )

21 aK

aK

+ − 1

min

f

=

( )

21 + − 1

max

where a is the individual particle anisotropy, which for
hematite is typically c . 1.4 - 1.45 (Kodama 2009 ), and