この地域の文献のうちネット上で入手可能なものとして http://linkinghub.elsevier.com/retrieve/pii/S0009254108005160
で表示される
M.J. Van Kranendonk, A. Kröner, E. Hegner, J. Connelly: Age, lithology
and structural evolution of the c. 3.53 Ga Theespruit Formation in the
Tjakastad area, southwestern Barberton Greenstone Belt, South Africa,
with implications for Archaean tectonics, Chemical Geology 261 (2009)
115–139
というものがあります(pdfは有料でした).
STOP1のTjakastad areaの地質に詳しい(全部にはとても目を通していませんが).
この地域のKomatiiteに関しては,下記の文献が参考になります(いずれも旅行後に気づいたものばかりで,これを調べておいて行ければよかったので
すが) http://sajg.geoscienceworld.org/cgi/content/abstract/103/1/47
J.C. Dann,2000: The 3.5 Ga Komati Formation, Barberton Greenstone Belt,
South Africa, Part I: New maps and magmatic architecture
<巡検3日め> Christoph Heubeck, Donald R. Lowe, and
Gary R. Byerly:
High but balanced sedimentation and subsidence rates (Moodies Group,
Barberton Greenstone Belt), followed by basin collapse: Implication for
Archaean tectonics,Geophysical Research Abstracts
Vol. 12, EGU2010-6260, 2010
の記述を参考にすると,
Largely siliciclastic strata of the Moodies Group form the topmost unit
of the Barberton Supergroup of the Barberton
Greenstone Belt (BGB), South Africa, represent one
of
the
world’s
oldest
unmetamorphosed
quartz-rich
sedimentary sequences, and reach ca. 3500m thick (Lowe and
Byerly, 2007). Large parts of the Moodies Group
were deposited in apparent sedimentary continuity in alluvial, fluvial,
shoreline and shallow-marine environments
(e.g., Eriksson, 1979; Heubeck and Lowe, 1994).
とあります.要するにこれだけの古さの堆積層でほとんど変成作用を受けていないというのがこ
の場所の特異性だとか.
あと,MoodiesG.のクロスラミナ砂岩の解釈が下記の論文のアブストに明瞭にかかれています. http://adsabs.harvard.edu/abs/2006SedG..190...13E Kenneth A. Eriksson, Edward L. Simpson and Wulf Mueller:
An unusual fluvial to tidal transition in the mesoarchean Moodies
Group, South Africa: A response to high tidal range and active
tectonics,Sedimentary
Geology
Volume 190, Issues 1-4, 1 August 2006,
Pages 13-24