I Introduction
II The concept of strain partitioning
II.1 Definition
II.2 Pure shear
II.3 Simple shear
II.4 The concept of vorticity
III Characterisation of strain
III.1 TranspressionIII.1.1 KinematicIII.2 Trantension
III.1.2 StrainIII.2.1 Kinematic
III.2.2 Strain
IV Structural geology of transpression
IV.1 Strike-slip faults
IV.2 Thrust
IV.3 Folds
V Structural geology of transtension
V.1 Strike-slip faults
V.2 Normal faults
V.3 Pull-apart basin
VI Geophysical characteristics of wrench zones
VI.1 Seismicity
VI.3 Heat flow
VI.4 Gravity anomalies
VI.2 Shear waves splitting
VII A case study: The Pacific/North American boundary
Reference list
NONE OF THE FIGURES HAS A PROPER REFERENCE.
There is almost no reference in the text and the few you give are not
listed in the reference list.
Even with a Table of Content this report shows a very poor organization.
The Title: Wrench-Style Tectonics. Tectonicists talk about: contractional tectonics, extensional tectonics, wrench tectonics. "-style" is unnecessary.
Introduction. Except for the two last lines describing the plan of your report, the rest of this introduction is a bit too vague, and is mainly composed of a succession of unrelated sentences. The removal of one phrase it has no implication on the understanding of this section.
This introduction is misleading and reveals some default on your understanding
of some concept. For instance it is written: Firstly, we will deal
with the mechanics of wrench tectonics...
Yet after reading the fist section of the report there is nothing about
the mechanics of wrench tectonics. Mechanics is the branch of physics
dealing with energy, forces and motion. In your first section you
do not talk about forces, instead you present some simple kinematic models
of wrench tectonics (homogeneous strain vs partitioned strain) after having
presented some basic concept (pure vs simple shear).
It is also written that: . Firstly, we will deal with... and the role of strain in deformation. This may reveal some default in your understanding of the concept of Strain and the concept of Deformation which are although related two different things. Check a textbook in structural geology for a definition of those terms.
What is missing in this introduction is some clues about what wrench tectonics is.
Section II: The Concept of Strain Partitioning.
Again: transform-style plate boundary = transform plate boundary. In science if you can define something in three words there is no needs to attach another term.
Your definition of strain partitioning lacks clarity. Strain partitioning refers to the fact that the strain is heterogeneous. In a wrench environment, not only the intensity of strain varies from zone to zone, but the strain regime also varies: there are zones dominated by simple shear strain regime, whereas in adjacent domains pure shear may strongly dominate.
Figure 1: In contrast to what the legend says, this figure does not show "strain directions".
II.3 Pure shear :
The first sentence: (This type of strain regime can be seen the successive stages of deformation in the Finite Strain Ellipsoid.) does not mean anything, it can be removed.
Figure 2: !!!!!!!!!! THIS IS NOT THE STRESS ELLIPSOID. CHECK YOUR FAVORITE TEXTBOOK IN STRUCTURAL GEOLOGY FOR THE DIFFERENCE BETWEEN STRESS AND STRAIN.
II.4 Simple shear
The simple fact that the axes rotate is not characteristic of simple shear. The intermediate axis of the finite strain ellipsoid should be an axis of non-deformation.
Figure 3: !!!!!!!!!!!!! THIS IS NOT THE STRESS ELLIPSOID.
Figure 3i: There is no explanation no one will understand the
meaning of this figure. The author should put himself in the position
of the reader.
III Characteristic of strain
III.1 Transpression
Yet transpression and transtension and mixed up in the figures. Very confusing.
The following sentence needs some explanation. In partitioned transpressive zones, pure shear is aligned perpendicularly and increases in positivity toward the plate boundary.
Figure 6 needs explanation.
IV Structural geology
IV.1. and IV.2 Very laborious, overall lack of clarity, the figures
are not readable..
Even with a table of content you manage to mix information. For
instance the figure 8, which is included in the paragraph IV.2 Thrust,
shows the orientation of folds which is the subject of the following section.
V Structural geology of transtension
Figure 12 has little to do with Normal Faults.
V.3 Pull-apart Basins
"Many strike-slip fault traces are present in the real world due to variations in rock metamorphic grades???????????????, existing deformation (folds and faults) ????????????and brittle /ductile rheologies Figure 13???????????????. These factors produce the variety of structures that we see in Figure 14." What is the relationship with Pull-apart Basins?
VII A case study
The writing style of this paragraph contrasts so much with the rest of the report that I personally doubt that it has been written by one of the authors of this report.
Figure 19 and 20 are useless without a proper explanation. Reports look even weaker when it is artificially inflated.
(Geology:1995). This is not a reference. Check on scientific
paper for a proper way to reference information taken from scientific journal
and books.