Temperature Data Processing


ODP logging contractor: LDEO-BRG

Hole: 859B

Leg: 141

Location: Chile Triple Junction (SE Pacific)

Latitude: 45° 53.72' S

Longitude: 75° 51.33' W

Logging date: December, 1991

Bottom felt: 2760 mbrf

Total penetration: 476.1 mbsf

Total core recovered: 169.67 m (46 %)


Water Depth: 2748.9 mbsl

Temperature Tool Used: LDEO-TLT

Depth versus time recording available: NO


Logging Runs


Logging string 1: ACT/GST/NGT

Logging string 2: WST

Wireline heave compensator was used to counter ship heave.


Tool Information


The LDEO-TLT tool is a self-contained, high precision, low-temperature logging tool that is attached to the bottom of the Schlumberger tool strings. The tool provides two temperature measurements (in degree Celsius, recorded by a fast-response and a slow-response thermistor.  The fast-response thermistor, though low in accuracy, is able to detect sudden, small temperature excursions caused by fluid flow between the formation and the borehole. The highly accurate, slow-response thermistor can be used to estimate heat flow. Pressure and the two temperature measurements are recorded as a function of time: conversion to depth can be based on the pressure reading (Legs 123-157) or, preferably, on simultaneous recording (by Schlumberger) of depth and time (Legs 159-181).


Data Processing


Depth was calculated from a depth/pressure table obtained by synchronizing TLT and GLT or WST tool at the bottom of the hole.

WST stations. Temperatures at individual stations were calculated by fitting an exponential decay curve to the temperature record at each station. Most stations were taken on the way up, except the one at 247 mbsf (on the way down).



Information about the temperature logging operations can be found in the Site Chapter (Operations, Downhole Measurements, and Heat Flow sections), ODP IR volume 141.


Cristina Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia