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The Middle Paleozoic section of the Appalachian Plateau exhibits a mechanical stratigraphy defined by layers that emit seismic energy with unique signatures in response to a strain energy accumulated on time scales associated with local, regional, and plate-scale processes. The Earth is in a state of frictional equilibrium, which means that even small changes in effective stress cause brittle failure and the concomitant release of ambient seismic energy. Stress changes as low as 0.001 MPa, the level of stress changes during Earth tides or the transmission of a fluid pressure wave, can activate failure on critically oriented fractures. These phenomena lead to a release of ambient seismic energy, which can be mapped using seismic emission tomography (SET) methods to image fracture networks emitting coherent seismic waves. We used a buried array of 54 sondes to identify active fracture networks over a contiguous volume of 3.76 km3 within Middle Paleozoic rocks hosting two Marcellus gas shale wells drilled under the Appalachian Plateau of Lycoming County, Pennsylvania, USA. We sampled ambient seismic emissions before and after two stimulations and found that the pattern was repeatable. The fracture patterns illuminated by ambient seismic emissions defined a mechanical stratigraphy populated by clouds of seismic activity separated by packages of beds emitting relatively less seismic energy. The unique attribute of the beds emitting less seismic energy is a lower least horizontal stress (Shmin) relative to adjacent mechanical units in the section. These low stress beds include the bottom portion of both the Marcellus and Burket/Geneseo black shales. There are three thicker mechanical units carrying clouds of higher energy emissions. These three units include siltstones of the Brallier above the Burket/Geneseo package, silty shale beds of the Mahantango between the Marcellus and Burket/Geneseo packages, and Silurian-Devonian carbonates below the Marcellus package. In map view, emission patterns in the Brallier follow Alleghanian J2 joints. Patterns in the Mahantango are consistent with slip along columnar joint zones like those cutting upward in outcrops of shale on the Appalachian Plateau. In sum, SET reveals a mechanical stratigraphy based on the release of strain energy from three major units of the Middle Paleozoic section.

A new signal processing algorithm tailored for in-situ applications combines multivariate analysis and hmable diode laser absorption spectroscopy. The principle and the application to the spectra separation of tetrafluoromethane and its interferants is demonstrated.

Breccias affecting the pelagic Lower Cretaceous Maiolica limestone of the Umbria-Marche Apennines of central Italy contain 10-cm-diameter to submillimeter angular clasts of white pelagic limestone and black chert, separated by a filling of sparry calcite. The clasts can often be seen to have originally fitted together, indicat- ing extension without shear, and this is the case in all three dimensions, arguing for roughly isotropic volumetric expansion. Breccia fragments are separated by sparry calcite bodies comparable in width to the fragments; this shows that the breccias were not formed by collapse, or by a single large explosion, after either of which the frag- ments would surely have fallen to the bottom of the cavity, but probably by multiple small expansion events, each followed by calcite deposition in the small voids that opened up. The breccia sometimes occurs in dramatic topographic walls, a few tens of meters in both width and height, although there is not a one-to-one correspondence between breccia and walls. The sparry-calcite fill indicates that water with dissolved CO2 was involved in formation of the breccias, presumably providing the high fluid pressure that forced the fragments apart. The breccia is bounded stratigraphically above by the middle Cretaceous Marne a Fucoidi (Fucoid marls), which appears to represent an aquiclude that limited the volume of high fluid pressure (PF). Although the mechanism of formation of the expansion breccias is not yet clear, we list obser- vations that need to be accounted for by such a mechanism and discuss how these observations might be explained.

Monitoring of perfluorocarbon (PFC) evolution from aluminium smelting is gaining attention, not only because of their high greenhouse gas potentials but also due to process optimization purposes. Conventionally, PFC monitoring has been conducted by extractive sampling and subsequent analysis by fourier transform infrared (FTIR) spectroscopy. With FTIR, the quantification can be performed by IR spectral features specific for PFC. The downside is a requirement of gas scrubbing to remove HF detrimental to the instrument as well as relatively poor gas dynamics due to the large internal gas volume of the instrument. With emerging quantum cascade laser (QCL) technology, online monitoring can now be conducted with duct mounted lasers with calcium fluoride optical windows. However, due to a strong spectral overlap of CF4 and other gas constituents present in the process (e.g. methane), the QCL instruments currently suffer from some cross-interference. In this work, QCL single cell PFC monitoring has been validated by simultaneous monitoring with FTIR.

Recent developments in quantum cascade lasers have enabled the development of new sensors for in-situ applications that have so far only been possible with extractive systems. In this work, a sensor is presented using a unique Wavelength Modulation Spectroscopy approach to measure tetrafluoromethane, a strong greenhouse gas. The sensor was characterized in a laboratory environment indicating a long-term detection limit of 20 ppb·m and a short-term value of well below 10 ppb·m. To demonstrate the feasibility of the sensor in a real-world environment, it was installed at an Alcoa aluminum smelter. A co-located Fourier Transform Infrared Spectrometer allowed direct comparison measurements of both systems. General agreement between the two methods was observed, leading to the conclusion that the developed in-situ quantum cascade laser based sensor has the potential to continuously measure tetrafluoromethane at aluminum smelters.

The classic work of Peach et al. (1892, 1907) is first set of quality geologic maps depicting the geometry of the Moine and related crystalline thrusts, and the foreland fold-thrust belt (FFTB) beneath. Modern detailed geologic maps (e.g., M. P. Coward, unpublished) have facilitated more detailed analysis of the Moine thrust zone. C. W. Hayes (1891) was mapping at the same time in the Georgia Appalachians and thinking about the consequences of retrodeformation of thrusts. High quality geologic maps in the Northwest Highlands and in other FFTBs worldwide, along with modern digital seismic reflection data, permit almost quantitative resolution of 2D thrust geometry. These yield the common shortened wedge, thin-skinned, ramp-flat, listric configurations characteristic of thrust belts that propagated into a wedge-shaped platform sequence. FFTBs worldwide are commonly driven toward continental interiors by either large crystalline thrust sheets generated during continent-continent collision, composite terrane or arc-continent collision, or ophiolite obduction. Retrodeformation and attempts to balance portions of linear FFTBs is more readily attainable than in curved segments. Plane strain can reasonably be assumed in linear FFTBs, making 2D sections amenable to line and area balancing. These have a good chance of meeting Elliott’s (1983) minimal viability criterion. Sections in strongly to moderately curved FFTBs may individually appear restorable, but retrodeformation of 2D serial sections produces overlap of their hinterland ends, making the incompatibility problem obvious. Moreover, outward radiating displacement vectors suggest there should be along-strike stretching that increases toward the outer portions of arcuate FFTBs. Evidence other than across-strike joints and veins is frequently lacking to support a stretching mechanism. Balancing of curved FFTB segments thus becomes a 3D material balancing problem (Laubscher, 1988), with major components of nonplane strain. Various 2–D solutions have been proposed, but they generally fail. Retrodeformation of 2–D cross sections through plastic thrust sheets in the internides of orogens presents even greater challenges. The obvious solution is to employ Laubscher’s 3–D material balancing principles in both FFTBs and orogenic interiors. It may be that our principles of restroration are incorrect. Computer software exists that attempts 3–D balancing, but currently is limited because of difficulties of writing codes that can incorporate multiple rheologies (more than Coulomb) and varied material properties. Sophisticated finite-element codes that accommodate more than one rheology and a host of parameters are currently limited to 2–D. Current reality is the recognition that 3–D material balancing is needed, but we still are limited to hand methods and obtaining enough field data. Possible solutions: (1) construct balanced 2–D cross sections through short, acrossand along-strike segments of FFTBs, and (2) construct and analyze displacement vector (particle trajectory) maps around curved segments of FFTBs, but finding enough quality displacement vectors that yield the regional vector field (slip lines) to permit 3–D balancing is difficult. Populations of usable structures are limited and unevenly distributed. Determination of regional displacement vectors remains the key starting point, however, because they track finite strain and provide paths for retrodeformation of curved segments of orogens.

We present a new technique to image deformation, 3D seismo-tectonic imaging, which juxtaposes instantaneous and accumulated deformation by combining earthquake and structural geology data. We test the technique using three independent data sets. We find concordance between the predicted finite deformation field and related instantaneous deformation surfaces inferred from aftershock and background seismicity data as well as structure imaged by seismic reflection data. These results indicate that: [1] The 1994 Northridge event ruptured a transverse, high-angle reverse fault linking two EW striking listric thrust systems, the Pico and Oak Ridge. The rupture terminated on the thrusts and was capped by a north dipping, forward-breaking imbricate of the Santa Susana Fault. [2] The Los Angeles Seismic Zone is a region of thrusting associated with the development of a new mountain front forming south of the present one represented by the Santa Monica Anticline. The thrust is rooted on a mid-crustal ramp forming beneath the Los Angeles basin. We conclude that seismo-tectonic imaging by linking earthquake data to an empirically based quantitative description of the finite deformation field provides a new and fruitful method for integrating geological and seismological data.

Periodic, short-term, extractive sampling with Fourier transform infrared (FTIR) spectrometers is often employed to measure perfluorocarbon (PFC) emissions at aluminum smelters. FTIRs have been routinely deployed by Alcoa to measure tetrafluoromethane (CF4) and hexafluoroethane (C2F6) gases during 2–4 week sampling campaigns at smelters worldwide. In conjunction with plant process logs, the data collected from these short-duration measurements are used to estimate production-normalized plant-specific PFC emission factors. Quantum cascade lasers (QCL) have recently become available for the mid-infrared monitoring of air pollutants. QCL-based, purpose-designed measurement systems could facilitate long-term in-situ stack measurement of CF4 at one or a few representative dry scrubber exhaust stacks. This paper discusses paired in-plant measurements by FTIR and QCL-based optical systems employed to develop future QCL measurement platforms and optimize the latter for long term stack PFC monitoring.

Time-division multiplexed spectroscopic measurements using a continuous-wave quantum cascade laser array, emitting around 5.65 μm, have been performed, preparing the way towards highly sensitive and selective continuous emission monitoring and portable multi-gas detection systems.

A mid-infrared sensor for sulfur dioxide in emission monitoring applications using a monomode DFB ICL at 4 μm and second harmonic detection has been developed. The detection limit of the sensor is below 3 ppm·m.

Mid-infrared measurements of tetrafluoromethane at ambient temperature and nitric oxide at elevated temperatures have been performed using continuous-wave room-temperature quantum cascade lasers and second harmonic detection.

Hydraulic fracturing generally creates a network of fractures of variable orientations and sizes, which depend on the pre-existing stress field and prevailing geomechanical conditions in the stimulated volume. We demonstrate that the compensated linear vector dipole of the composite moment tensor and the seismic consistency of induced microseismic events can be used to characterize fracture complexity and stress field variability in the stimulated volume. In the case study presented, the group of micro-earthquakes is dominated by strike-slip events with N-S striking rupture planes, resulting in a small CLVD component in the composite moment tensor. Nevertheless, the presence of few events with different mechanism types suffices to lower the value of the seismic consistency for the study volume. This demonstrates how sensitive this parameter is to variations of the stress field. The so inferred hydraulic fracture complexity may be used to evaluate the effectiveness of the stimulation, from which implications for well production can be inferred, and strategies for field management developed.

Mid-infrared measurements of sulfur dioxide at gas-temperatures up to 400 °C have been performed using a continuous-wave room-temperature quantum cascade laser and second harmonic detection.

Two new near- and mid-infrared spectrometers for in-situ measurements in harsh environments are presented in this paper including their development from an idea through a laboratory prototype to an industrial instrument.

A widely tunable difference frequency generation based mid-infrared spectrometer for the detection of sulfur dioxide (SO2), nitrous oxide (N2O), and methane (CH4) above 7 μm has been developed for industrial applications.

A novel, high brightness, transmitter for CO2 DIAL is presented. The single-mode output of a frequency controlled, entangled-cavity nanosecond OPO is amplified to >10 mJ at 2.05µm, with 3MHz frequency stability and M2 < 1.5.

We report on a novel 2 μm laser transmitter for CO 2 DIAL, based on a nanosecond parametric master oscillator-power amplifier architecture. The master oscillator is an entangled-cavity, doubly resonant, optical parametric oscillator, based on a type-II periodically poled Lithium Niobate nonlinear crystal. This device provides single-longitudinal-mode radiation, with a high frequency stability and high beam quality, with no need of an additional seeding source. The 2.05 μm signal emission is amplified by multi-stage parametric amplifiers to generate more than 10 mJ. After amplification, both the spectral purity and beam quality are maintained: we demonstrate single-longitudinal-mode emission with a frequency stability better than 3 MHz rms, within a nearly diffraction limited beam, with a M 2 quality factor close to 1.5. The unique performances of this parametric architecture make this device a relevant transmitter for CO 2 differential-absorption LIDAR. Such approach could be readily duplicated for the detection of other greenhouse gases.

Recently, laser specifications for a spaceborne sensitive measurement of CO 2 , by differential absorption LIDAR (DIAL) at 2.05 µm, have been derived in terms of output energy, frequency stability and beam quality [1]. In particular, the laser transmitter frequency should be stabilized a few GHz away from the centre of the R30 CO 2 line, with a stability around 2 MHz rms, at tens of mJ of energy levels, within a diffraction limited beam.

For CO2 DIAL, the single mode output of a type II PPLN, entangled-cavity nanosecond OPO is amplified to 11 mJ at 2.05 µm, with 3MHz frequency stability and a M2quality factor better than 1.9.

For CO 2 differential-absorption LIDAR, the single-mode output of a type-II PPLN entangled-cavity nanosecond doubly-resonant OPO emitting at 2.05 µm is amplified to 11 mJ, with 3 MHz rms frequency stability and a M2 ≪ 1.9.

We report on a 2.05 microm nanosecond master oscillator power amplifier optical parametric source for CO2 differential-absorption lidar. The master oscillator consists of an entangled-cavity nanosecond optical parametric oscillator based on a type II periodically poled lithium niobate crystal that provides highly stable single-longitudinal-mode radiation. The signal emission is amplified by a multistage parametric amplifier to generate up to 11 mJ in a nearly diffraction-limited beam with an M2 quality factor of approximately 1.5 while maintaining single-longitudinal-mode emission with a frequency stability better than 3 MHz rms. This approach can be readily applied to the detection of various greenhouse gases.

1 method is provided for obtaining an extended field of view diagnostic ultrasound image. image frame and a second image frame of an object of interest are acquired. The image are rotated relative to one another. Pixel points, representing spatial points in the object rest, are identified in the first image frame. Pixel points corresponding to the pixel points first image frame are then computed in the second image frame. A rotation angle en the first and the second image frames is calculated based on a least-squares relation en the pixel points. The first and second image frames are combined to form a part of an ded field of view image.

A three-dimensional projection image representing a projection of a data volume at a predetermined orientation, three cut plane images representing respective mutually orthogonal planar cuts through the data volume, a graphical representation of the data volume at that orientation and graphical representations of the cut planes are displayed in spaced relationship. Each of the cut planes has a respective positional relationship to the data volume graphic that corresponds to the positional relationship of the respective cut plane to the data volume. The graphical representations are displayed in different colors. Any one of the four images can be active in the sense that images are reconstructed in real-time as a trackball is moved. Which of the four images is active is indicated by displaying the corresponding graphical representation in a color denoting the active state.

Recent studies in southern California suggest that long-term deformation rates are far in excess of that which can be accounted for by historical seismicity, and thus, a deficit of moderate and/or large earthquakes exists in southern California. Although possible, this conclusion is not unique because aseismic deformation may have contributed to bulk regional strain. We examined Cretaceous to Pleistocene sedimentary rocks exposed in the Ventura basin along four cross-strike traverses to evaluate the possibility that aseismic deformation contributed to regional shortening. Our field and microstructural investigations suggest that aseismic deformational mechanisms, particularly pressure solution, contributed significantly to permanent shortening strain during the late Neogene and that the proposed seismic deficiency may be overestimated.

Evidence is presented for the existence of three fundamental mechanisms by which thrust sheets move. The mechanisms are: (1) failure of a stiff layer, to form ramp-flat geometry (‘imbricated’ thrust sheets); (2) detachment of a layer by folding (‘decollement” thrust sheets); (3) differential layer-parallel shortening (‘LPS’ thrust sheets). The mechanisms are independent but may operate interactively to form families of ‘hybrid” thrust sheets. Since LPS thrust sheets have not been previously described or documented, data from the New York plateau, deformed almost exclusively by differential LPS, is presented to demonstrate the physical characteristics of this thrust mechanism. Information from the plateau indicates that finite-strain behavior closely reflects the geometric boundary conditions and is independent of temperature and depth of burial. Finite-strain data are used to construct a set of iso-strain maps in both the deformed and undeformed states. The iso-strain maps are in turn used to determine the displacement field for the thrust sheet. The displacement field allows visualization of the effects of both Lagrangian and Eulerian transformations on an initially orthogonal grid. Utilizing sections from a number of overthrust belts, it is shown that the three mechanisms occur universally although in various proportions. LPS is regionally developed throughout the central and northern Appalachians. The presence of the LPS thrust sheets probably accounts for the failure of structural cross-sections to bed-length balance in these blind thrust terranes. Finally a series of examples drawn from the field as well as the literature are used to illustrate both the characteristics of hybrid thrust sheet families as well as to indicate how knowledge of their behavior can be utilized in developing strategies for the construction and balancing of structural cross-sections.

Rowley and Kidd (1981) describe stratigraphic and petrologic evidence for the evolution of the Taconic Allochthon in which they conclude that it originated by east to west stacking during obduction of a continental rise sequence onto the Cambro-Ordovician shelf. Although the general model they present is quite convincing, I find that their conclusions regarding the timing of the final assemblage of the Taconic terrane into its present form has some serious flaws which result from the failure of Rowley and Kidd (1981) to adequately discuss either the nature of the fault systems within the Taconics or the well established evidence for post-Taconic deformation in the Hudson Valley. According to their analysis, the fault system principally responsible for the present structural relations has two characteristics: (1) it is post-metamorphic; (2) it is decorated by slices of carbonate shelf and occasional pieces of Precambrian crystallines. Although not explicitly stated, it is strongly implied by figure 1 (Rowley and Kidd 1981) in particular that the structural framework of Taconic deformation described from their northern study area applies to the entire Hudson Valley. If indeed this is meant, then their work contains major omissions of important structural data which directly conflict with the timing of their synthesis at least as far north as Albany. The conflict is generated by the presence of two distinct fault systems and unequivocal evidence of major post Taconic deformation in the lower and central Hudson River Valley. The existence of the two fault systems

Given the direction cosines a i ′ = (a 1 i , a 2 i , a 3 i )corresponding to a set of pspherically projected fabric poles, an initial estimate x′ = (x1, x2, x3, x4)for the angular radius x4,and direction cosines of the center of the least-squares small circle which minimizes the sum of the squares of the angular residuals $$r = \sum\limits_p {\left[ {x_4 - \cos ^{ - 1} \left( {a_1^i x_1 + a_2^i x_2 + a_3^i x_3 } \right)} \right]} ^2 $$ can be iteratively improved by taking xj+1 = xj + Δxwhere xj is the value of xat the jth iteration and $$\Delta x = - H_j^{ - 1} \left[ {q_j + x_j \left( {x'_j H_j^{ - 1} x_j } \right)\left( {q_j - x'_j H_j^{ - 1} q_j } \right)} \right],$$ where As an initial approximation for xwe have found it convenient to ignore the fact that the data are constrained to lie on the surface of the reference sphere and to use the parameters of a least-squares plane through the given poles. Generalization of this approach to fitting variously constrained great and small circles is easily made. The relative merits of differently constrained fits to the same data can be tested approximately if it is assumed that the errors in the location of the poles are isotropic and normally distributed. It is thus possible to statistically assess the relative significance of conflicting structural models which predict different geometrical patterns of fabric elements.

To compare the orientation and development of jointing with the orientation and magnitude of finite strain recorded in the Upper Devonian rocks of the Appalachian plateau, New York, we mapped systematic joint sets on an area of 20,000 km2. In this area, Wedel [1932] mapped folds with limb dips of less than a degree and axes that change strike by 30° from 090° in the east to 060° in the west. We observed two different cross-strike joint sets that maintain their approximate cross-strike position from east to west. Yet, in detail the angle between the sets is 18°±2° in the east and 30°±4° in the west. In many outcrops one joint set parallels the direction of maximum compressive strain (eƒ) as recorded by deformed fossils, whereas the other joint set never parallels eƒ. Rare calcite-filled joints are oriented parallel to the direction of eƒ. In addition, the calcite-filled joints both cut and are cut by solution cleavage. These observations suggest that the joint set paralleling eƒ formed during the deformation event represented by the deformed fossils. The joint set that does not parallel eƒ somehow reflects a deformational event other than that producing fossil distortion, as suggested by strain relaxation experiments. In an outcrop of the Machias formation, where the direction of eƒ is 15° from the trace of a cross-strike joint set, the tensor average from 14 subsurface strain relaxation tests shows in situ maximum comprehensive strain (eoc = 10−4) parallel to cross-strike joints but not the direction of eƒ. Strain relaxation is coaxial with a fabric anisotropy indicated by sonic velocity tests. Our idea is that the orientations of cross-strike joints parallel to eoc were controlled by the same rock property that causes strain relaxation on overcoring, whereas the orientations of the cross-strike joints parallel to eƒ were controlled by the stress field causing the fossil distortion. Placing these structural data in a regional context allowed us to construct a dynamic and kinematic model for the structural evolution of the New York plateau. The model indicates variation in both boundry conditions and material behavior through a series of four distinct deformational events, which begin prior to lithification and end in the Recent. Thus our analysis suggests that the structural features we have used represent a set of highly sensitive tools for investigating the deformational history of the Appalachian foreland.

Change and stability can be understood not as polar opposites but as conditions necessary to the viability of organic life. Social transformation may be accomplished, in part, because there exists a mythopoeic faculty which during processes of transformation acts to preserve one's self-concept and collective identification. Although the Nubian practiced labor migration over centuries, he asserts, today, that no one could have left Nubia had it not been for the construction of the Aswan dam in 1902. By reference to the mythical effect of the dam on his natural history, the Nubian could bring into congruence the apparent contradiction between his urban commitment and his loyalty to collective sentiments. Allegorically, by extracting his migratory behaviors from their historical roots and by attaching them to an artifact of symbolic significance for the collectivity, migration would represent no denial of his relation to nature. Myth and ritual may be cohesive forces when they act on a society undergoing change.

This paper is an analysis of selected aspects of population movement, with special reference to the case of Nubia. It examines a portion of the data collected in the years 1961-1964 during the course of an anthropological-sociological study of Nubian society, including both the villages of Egyptian Nubia and the urban communities of Egypt and the Sudan. Specifically, the paper describes the Nubian community in historical perspective, sketching out some of the salient geographic, economic and demographic features. The empirical data is analyzed with reference to a selected theory of migration phenomena.

Participation in the professional associa tion's decision-making process as inferred from meeting attendance and committee membership is differentially related to the social base of the group structure. Differ entials in participation cannot be exclu sively ascribed to an aggregate of individual apathy or personal preference. The degree of participation also reflects group differ ences in professional identification, inter group linkage value, potential for critical detachment, and circulation of the elite. "The association based upon some partic ular interest is the discreet. .. form par ex cellence." 1 This paper examines limited as pects of the decision-making process which are influenced by social factors within the processes and structure of a professional association. The study is mainly concerned with the extent to which the members of a

The strata of the northern Umbrian Apennine fold belt are cut by an array of mesoscopic faults that generally display strike- or oblique-slip offset. The majority of these faults have traces less than a few metres long and represent displacements of < 10 cm. Fault surfaces are associated with stylolites and are coated with elongate calcite fibers, suggesting that movement occurred by the mechanism of pressure-solution slip. Crosscutting relationships indicate that faulting occurred before, during, and perhaps after regional folding. The slip on the faults permitted translations of mesoscopic blocks with respect to one another, thereby accommodating regional strain. There is a great range among fault attitudes, but two clusters forming a conjugate set with about a 90° dihedral angle stand out. The mean trend of left-lateral faults of this pair is N72°E, whereas the mean trend of right-lateral faults is N16°W. The bisector between these two fault clusters is about 15° away from the normal to the regional fold axes. This unusual orientation pattern of mesoscopic faults of the study area may indicate that the mechanics of initiating faults in rocks undergoing pressure-solution deformation is different from that in rocks undergoing purely brittle deformation. Alternatively, the fault pattern may indicate that the faults represent slip on pre-existing fractures. If this latter situation is true, the geometry of the fault array may merely reflect the geometry of the pre-existing joint array.

Here we call attention to a weakly developed pencil cleavage as an indicator of the pervasiveness of lateral shortening within the sedimentary sequence of the Appalachian Plateau. The pencil cleavage appears in Upper Devonian shales as a set of closely spaced vertical partings, and it gives the shale a crude lineation similar to the pencil structures in slate districts. The strike of the shale pencil structures parallels the strike of stylolitic solution cleavage in limestones and is normal to the direction of lateral shortening indicated by deformed fossils. These deformation markers generally conform with the variation in trend of the Appalachian Plateau folds. Where the strike of the pencil cleavage diverges from the fold axes, the relation between cleavage and folding suggests that the cleavage formed first.