MAGNETIC SUSCEPTIBILITY

INTRODUCTION

The Susceptibility data file contains the susceptibility

measurements taken onboard JOIDES Resolution. A Bartington

M.S.1 Magnetic Susceptibility meter on the ship can measure

discrete samples or whole core sections passed through the

instrument's sensor loop.

The data are collected directly from the susceptibility meter

onto the shipboard VAX computer and brought back to shore on

magnetic tape. These data files contain measurements made on

whole core sections.

BIBLIOGRAPHY

Shipboard Scientific Party, 1987. Explanatory Notes. in

Srivastava, S. P., Arthur, M. A., Clement, B. M., et al.,

Proc., Init. Repts. (Pt A), ODP, 105.

DATA ITEM FORMATS

LEG

SITE

HOLE

CORE

CORETYPE

SECTION

TOP_INTERVAL

BOTTOM_INTERVAL

SUB_BOTTOM_DEPTH

SUSCEPTIBILITY

RUN_NUMBER

EXPLANATION OF THE SUSCEPTIBILITY DATA ITEMS

LEG - Number identifying the cruise.

SITE - Number identifying the site. A site is the position of

a beacon around which holes are drilled.

HOLE - Letter identifying the hole.

CORE - Number identifying the core. Cores are numbered

serially from the top of the hole downward.

CORETYPE - A letter code identifying the drill bit/coring

method used to retrieve the core. The coretype codes are:

B - Drill Bit

C - Center Bit

D - Positive Displacement

H - Hydraulic Piston Core

M - Miscellaneous

N - Downhole Mud Motor (Navidrill)

P - Pressure Core Barrel

R - Rotary

S - Side Wall Core

W - Wash Core

X - Extended Core Barrel

SECTION - A core is cut into 1.5 meter long sections that are

numbered serially from the top of the core. A core with full

recovery will have 7 sections and a core catcher and be

approximately 9.8 meters long.

TOP_INTERVAL - The location of the top of a sample within a

section in centimeters.

BOTTOM_INTERVAL - The location of the bottom of a sample

within a section in centimeters.

SUB_BOTTOM_DEPTH - Distance in meters from the seafloor to

the top of the sample interval.

SUSCEPTIBILITY - The value is in x10-6 cgs units and is

volume corrected.

RUN_NUMBER - Each run of the MST is given a number which

increments by one with every test.