NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Regolith layering processes based on studies of low-temperature volatile elements in Apollo core samplesThe concentrations of Hg released at at the most 130 C increase with depth in near-surface samples from cores. This is in response to a daytime thermal gradient with temperatures of approximately 400 K at the surface decreasing to approximately 250 K at greater than 10 cm depth (Keihm and Langseth, 1973). The steepness of the slopes and the depths to which the concentration gradients extend appear to be determined by the color, density and possibly the grain size of the soils. Earlier surface layers can be identified and, in general, are in agreement with other indicators of such layers. Low temperature volatilized Br exhibits trends that parallel those of Hg in a number of cases. This is also true of Br and Hg fractions released in stepwise heating experiments at higher temperatures. The coherence, especially in higher temperature fractions, between these chemically dissimilar elements implies a common physical process of entrapment; possibly one related to the presence of vapor deposits on surfaces and to opening and closing of microcracks and pores.
Document ID
19800039463
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Jovanovic, S.
(Argonne National Lab. IL, United States)
Reed, G. W., Jr.
(Argonne National Laboratory Argonne, Ill., United States)
Date Acquired
August 10, 2013
Publication Date
January 1, 1979
Subject Category
Lunar And Planetary Exploration
Report/Patent Number
CONF-790381-1
Meeting Information
Meeting: Lunar and Planetary Science Conference
Location: Houston, TX
Start Date: March 19, 1979
End Date: March 23, 1979
Accession Number
80A23633
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available