AAPG Bulletin; June 2006; v. 90; no. 6;
p. 975-982; DOI: 10.1306/12130505142
© 2006 American Association of Petroleum Geologists (AAPG)
Climatic significance of Holocene beachrock sites along shorelines of the Red Sea: Reply
Gerald M. Friedman1
1 Northeastern Science Foundation, Inc., Rensselaer Center of Applied Geology, 15 Third Street, P.O. Box 746, Troy, New York 12181-0746; gmfriedman@juno.com
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Mozley and Burns' (2006) discussion reminds me of current discussions on paleotemperature elsewhere. In the July 29, 2005, issue of Science, the following statements are presented: "Two teams of researchers, studying the same evidence with the same techniques, have painted diametrically opposite pictures of a key period in the history of Earth's climate, which climatologists are probing...It's a tough issue to sort out...‘What's at stake is the regional distribution of climate,’ both past and future" (Kerr, 2005, p. 687). We have to wait for more data. This is difficult work, and it is easy to be misled.
Before answering specific criticism, please note that my study was a geologic note and not a full article. My detailed article (Friedman, 2004) was published as part of a special publication series requested by the Geochemical Society as part of its tribute to Isaac R. Kaplan. I refer Mozley and Burns (2006) to the details of my article.
I shall answer their criticism.
DESCRIPTION OF THE PETROGRAPHIC CHARACTERISTICS OF THE SAMPLES
The studied beachrock is composed of (1) terrigenous debris derived from nearby bedrock, (2) carbonate particles of local origin, and (3) carbonate cement (Friedman, 1988; Table 1).
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Table 1 X-Ray Diffraction Mineralogical Analysis*
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The most common beachrock lithology is terrigenous calcipebblestone (Figure 1) and calcisandstone in which skeletal debris is minor or absent, terrigenous rock fragments are dominant, and carbonate cement is abundant. Terrigenous debris does not affect radiocarbon dating nor carbon or strontium isotopic measurements because in most of the samples, the debris does not generally contain carbonates. The samples selected for the study contain fossils only sporadically, or at best, fossils are entirely absent.
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Figure 1 Beachrock with abundant included terrigenous pebbles paving intertidal zone and extending into supratidal zone on the west side of the Gulf of Aqaba.
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Terrigenous particles in the . . . [Full Text of this Article]
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