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Data Import Directions Means CMTD Foldtest E-I Shallowing Settings

Paleomagnetism.org 2 - Statistics

Data from the Paleomagnetism .col format can be imported to the statistics portal. Each selected file and group will be associated with a new selectable collection. An alternative example of the default input file can be found here.


Statistics - Geomagnetic Directions

Figures showing the selected collections and their geomagnetic directions & distribution of virtual geomagnetic poles. The right figure does not show actual VGP positions. The table lists standard Fisher parameters for this set of directions. When multiple collections are selected, its components will be combined before a cutoff is applied. Press 8 and 5 to switch between coordinate frames and confidence ellipses respectively. Below you'll find an inclination-only statistics table.

Note: TThe illustrated zenital VGP distribution and cutoff is relative to the mean and does not show true VGP positions. In that projection all directions are assumed to come from the same geographic location.



Inclination-Only statistics

Paleomagnetic directions record declinations and inclinations. In some cases, due to structural problems or lost azimuths in drill cores, only the inclinations are reliable. The arithmetic mean for inclination-only data is biased towards shallow inclinations In this table you can check the differences between the arithmetic mean and inverse variance and the Arason and Levi, 2010 Maximum Likelihood Method that estimates κ and α95.


Statistics - Mean Geomagnetic Directions

Figures showing the mean direction of the mean of all selected collections seperately. Press 8 and 5 to switch between coordinate frames and confidence ellipses respectively. The selected cutoff is applied to each collection.


Statistics - Common Mean Direction Test (CMDT)

Select two collections and click initialize to begin the bootstrap. (A) Tauxe et al., 2010 CTMD test. Overlapping distributions indicidate that two collections are the same within confidence limits. (B) CMDT from Heslop et al., 2023, showing the histogram of λ(b)min. If CMTD value is less than the critical value directions are not different.









Statistics - Foldtest

This module allows the user to do a classical foldtest (Tauxe & Watson, 1994) and an inclination only tilt test (Enkin & Watson, 1996) on one or multiple collections. No cutoff will be applied. Select any number of collections and click initialize to start.


Pick which foldtest you want to execute

Pick between Inverse variance and Arason-Levi's κ (only needed in case you want to execute Inclination-Only Foldtest)

 






Statistics - Shallowing

The inclination shallowing module unflattens observed inclinations in sediments to fit with the TK03.GAD Field Model (Tauxe et al., 2008) based on the relationship between the expected elongation (E) (τ2/τ3) and inclination. The flattening function of (King, 1955) is applied. A single collection can be selected and a cutoff will be applied. A minimum of 80 directions are required. The procedure can be bootstrapped 1000 times to find its confidence limits.

 


Select Cutoff

A pole-cutoff can be selected that will be applied to the polar distribution.

Sorting Options

Keyboard Shortcuts
Cycle Confidence Ellipse (α95, A95) Cycle Coordinates Save Selected Collections Remove Selected Collections Copy selected collection to clipboard
5 8 s q e

Preferences

Application Reset
The application will be resetted as local storage will be cleared. Export your data manually to save it.

Add New Collection
Collection Name

°N
°E

Age
Min
Max

Note: metadata is applied to all components in collection. To assign more metadata to each component choose an alternative input method.


Fill in: declination, inclination, ((bedding strike, dip), and name).

DOI
Authors
Year
Save Collection

A new collection can be saved from the currently combined selection. Rejected components can be discarded and all components can be reversed.

Collection Name