A synthesis of data from many parts of the planet and further
interregional comparisons are the best ways to obtain a comprehensive
vision of the geological evolution. On the basis of his own field
work in various places, including the North Lehrbücher,
zusammenf. Darstellungen, Bibliographien 581 American Cordillera, the
Andes, the Alps, the Himalayas, etc. and a careful revision of a huge
number of literature sources, ROEDER has composed a general review of
knowledge on the tectonics of fold-thrust belts, which are impressive
scars on the Earth's surface. His fascinating book is concise, but
very comprehensive. It touches a lot of aspects of the structure and
the evolution of this type of active zones, whichare clarified in 13
chapters. The book starts with the general state of knowledge on the
fold-thrust belts and principles of their study. These belts are
further described in the terms of plate tectonics. Subduction on
continental margins is an essential process of their formation. The
Cordillera-styled tectonics and orogen growth enable the fold-thrust
belt evolution. ROEDER recognizes rift-fill/syn-rift, passive-margin,
foredeep, and successor basins and oceanic accretionary wedge as the
main depositional systems of orogens. The author extracts the best
from the geosyncline terminology and also mentions such a “new” tool
as sequence stratigraphy. Internides and externides are further
considered. It is stated that fold-thrust belts belong to
externides. Very interesting passages concern the stockwerk tectonics
of East Greenland. Four styles of the fold-thrust belts are described
in this book. They are the Dahlstromian style, the Biotian style, the
style of basement upthrusts, and the slate-belt style. Their
recognition seems to be intuitional, but well-describing the true
diversity of the discussed tectonic belts. The author’s definition of
the term “structural style” (p. 73) is very appropriate. Although this
term has a very wide use, a particular definition is very necessary,
especially for beginners in science. It is assumed that a mixture of
externide and internide styles is possible, and structures with such a
mixture are called the Mesonides. A representative example is a
discordant thrust fault. A special chapter gives a synopsis of
structural details of the externide fold-thrust belts, including
flexures and duplexes. The author of this book is absolutely right,
when emphasizes on an outstanding importance of major strikeslip
displacements in the evolution of fold-thrust belts. The same was
reported by RUBAN (2007), although the latter also concluded that some
lateral displacement systems were of global extent and, thus,
superposed orogenic structures.
Fig. 108 (p. 124) indicates that left-lateral displacements are
preserved in the Hercynian chains of eastern North America and Western
Europe. This is a true, but perhaps it would be necessary to add that
sinistral motions followed even more impressive dextral motions in the
same region (see review in RUBAN 2007). A collage of tectonic sketch
maps depicting strike-slip structures in the fold-thrust belts
(Figs. 105-108, pp. 122-124) is a powerful evidence of an efficacy
furtherinterregional comparisons. Well, even in such a particular
case, ROEDER did a great deal. A significance of gravitational forces
in the evolution of the fold-thrust belts is also stressed and
deserves to be discussed in the special chapter. The book ends with
some notes on petroleum exploration. Although little or moderate in
size, new oilfields remain to be discovered in the world fold-thrust
belts. However, drilling within the latters encounters pitfalls,
particularly because of an inadequate interpretation of complicated
geological structure.
ROEDER is a really talented writer. In some other publications,
structural geological explanations are often too obvious and too
discouraging. Fortunately, this is a not a true in the reviewing book,
where lengthy and unnecessary physical explana582 Paläontologie
allgem. tions and redundant theoretical examples are avoided and
replaced with simple remarks and examples from the real fold-thrust
belts. The author’s writing is very personal and
stimulating. Meantime, ROEDER reviews the problems comprehensively and
a logical order of explanations stretches throughout the book. In
other words, his personal style is feeling, but it does not coordinate
the book. The latter is richly-illustrated. Figures are very numerous
and very detailed. Their uniform style strengthens the author’s
explanations and permits the readers to attempt some intriguing
comparisons themselves. Similarly-drawn cross sections of the
foldthrust belts (e.g., Fig. 83, p. 93 and Fig. 97, p. 109) underline
the common patterns of the latters. The subject index, although it is
extended, requires to be justified. Some important terms like
“geosyncline” are omitted, whereas only one page is referred to
“Moho”.
ROEDER has written an outstanding book. It joins the best traditions
of structural geological analysis (most probably, rooted into the
European tectonic schools of thoughts) with the newest achievements of
geology. Undoubtedly, it should stay on a shelf of every geologist, if
even he is not a structural geologist. This is an outstanding review
of the fold-thrust belts tectonics, which shares all features of the
classic never-outdating geological literature. Besides trained
scholars, it will also be appreciated by students. The reviewer, who
judges this book as one of his favourites, is waiting impatiently for
a publication of another volume by ROEDERannounced in the preface of
the current edition. Both books, i.e., reviewing and forthcoming, are
together a quintessence of the author’s career, which, however, does
not mean its decline pointed by the author himself. Further books from
ROEDER will be very welcomed by the broad geoscience community!
References RUBAN, D. A. (2007): The southwestern margin of Baltica in
the Paleozoic-early Mesozoic: Its global context and North American
analogue. – Natura Nascosta, 35: 24–35; Monfalcone, Italy.
D. A. RUBAN
Zentralblatt Geo. Pal Teil II 2009 Heft 3/4
