Airphoto Lineaments Research Articles

The Hyden fault scarp, Western Australia: paleoseismic evidence for repeated Quaternary displacement in an intracratonic setting

We present new paleoseismicity data for the 30 km long and 2.5 m high Hyden fault scarp in Western Australia, which, when combined with the results of previous research, provides the most extensive record of surface-rupturing earthquakes yet assembled for an ‘active’ Australian intracratonic fault. The data indicate that four to five surface-rupturing earthquakes have occurred on the Hyden Fault during the Quaternary (E1, ca 20 ka; E2, ca 55 – 50 ka; E3, ca 100 – 90 ka; and two events E4 and E5, >200 ka). Activity is episodic, with single seismic cycle slip rates varying from 0.03 mm/y to <0.01 mm/y. Paleo-earthquake magnitudes are estimated to have been in the order of M w 6.8. The identification of a similar fault scarp immediately northwest of the Hyden scarp, and of two airphoto lineaments to the west of the Hyden scarp, indicates that strain is distributed among a family of faults in this region. The presence of multiple nearby active faults suggests that the recurrence of severe ground shaking in the Hyden region is more frequent than indicated by the paleoseismic data presented here.

Image analysis techniques for the interpretation of airphoto lineaments ‐ petroleum exploration, Eromanga Basin, Australia

Abstract A technique is described for transferring interpreted data from a number of airphotographs to an orthogonal map base. A Landsat MSS image is registered to a topographic map and then is used as a digital map base for subsequent operations. The many scale errors associated with the use of a large number of airphotographs are removed by registering both photographs, and interpretations of the photographs, to the Landsat image. The use of this technique for the compilation and analysis of lineaments present on forty‐five airphotographs is described. Computer aided analysis of the coregistered lineaments facilitates a structural analysis of a petroleum prospective part of the Eromanga Basin in central Australia. The lineaments are shown to be surface features formed in recent sediments draped over subsurface basement structures.

Airphoto lineaments and fracturing in the axial ranges of the central North Island, New Zealand

Abstract Basement greywackes form the frontal ridge in the subduction complex associated with the active plate boundary a10ng the east coast of the North Island. Four main lineament sets, trending NW, N-S, NNE and NE can be recognized. All four correspond with faults mapped in the field. Some of the faults probably have been inherited from Cretaceous-Early Tertiary rifting of New Zealand away from Gondwanaland. Models proposed for causes which may have influenced the fault pattern are: (1) Riedel shear array; (2) dextral bending; (3) along-strike compression of the subduction complex; (4) down-dragging of the subduction complex.

Cross-Strike Structural Discontinuities: Possible Exploration Tool for Natural Gas in Appalachian Overthrust Belt

Cross-strike structural discontinuities (CSD's) are broad, diffuse, transverse zones of structural disruption in the Appalachian and other overthrust belts. At Parsons and Petersburg, eastern West Virginia, CSD's are 8 to 10 km wide. Folds of various scales, longitudinal faults, and unmodeled gravity anomalies terminate or change style across or within the two CSD's. Both CSD's are visible on Landsat images. Wherever tested, CSD's contain larger or more abundant joints, normal faults, or both, than do surrounding areas. Mapping usually reveals little displacement across transverse faults that parallel or lie in some CSD's. The CSD's appear to have divided the detached sedimentary prism into quasi-independent structural blocks. Median values of sizes and spacings of the Pa sons, Petersburg, and nine other Appalachian CSD's suggest that each CSD contains about 980 cu km of intensely fractured rock, and that CSD's constitute about 14% of the detached sedimentary rocks. CSD's and their extensions into the foreland can be loci of exploration in gas-producing fractured Devonian clastic rocks of the Appalachian basin. Many short air photo lineaments are surface expressions of fractures or fracture zones. Wells should be sited at intersections of short air photo lineaments in the CSD's.

Cross-Strike Structural Discontinuities--Exploration Rationale for Eastern Plateau Province: ABSTRACT

Cross-strike structural discontinuities (CSDs) are zones of structural disruption several kilometers wide in the Appalachian and other overthrust belts. CSDs are not faults or fault zones. They typically contain about 1,000 cu km of unusually fractured rock. For example, in eastern West Virginia, one CSD (Parsons lineament) trends west-northwest at least from the Appalachian front to the Intraplateau structural front, with no evidence of basement involvement. The Parsons lineament has double to triple the normal joint intensity in exposed Upper Devonian siltstones. Another CSD (Petersburg lineament) trends west-southwest from the western Valley and Ridge province, and crosses the Appalachian structural front. The Petersburg lineament aligns with Arkle's hinge line, a prob ble basement flexure under the western and central Plateau province, and has twice-normal joint intensity in exposed Lower Pennsylvanian sandstones. The two CSDs appear to intersect in southern Tucker and northern Randolph Counties, West Virginia. CSDs and their intersections, particularly beneath intersections of short air-photo lineaments, may comprise highly permeable fractured reservoirs. If the seal is preserved, CSDs can provide a tool for extending exploration into the little-tested eastern Plateau province of West Virginia and adjacent states, where organic-rich Devonian shales are thick and thermally mature. End_of_Article - Last_Page 1591------------

Airphoto Lineaments in the Caledonia Area of Southern New Brunswick

A system of photogeologic interpretation has been applied on a regional scale in the Caledonia area of New Brunswick, Canada, The orientation of about 700 photolineaments has been measured and their distribution analysed. A statistical partitioning technique applied to the whole region produced six major trends with the strongest trends occurring at 097o±7o, 165o±6o and 141o±9o . None of the strong trends coincides with the orientation of major faults in the area. Detailed examination of structural domains suggests the presence of more than six lineament trends. Correlation of trends from domain to domain is difficult and the genetic significance of lineaments in view of the scarcity of ground information remains in doubt.

Geological Study Using Photogeologic Interpretation (Part-I)

This paper presents the result of a geological study using photogeologic interpretation in the Agematsu area including the Kiso River basin.In Japan, the photogeologic interpretation have been studied only qualitatively, but the quantitative interpretation were not yet utilized fully in the photogeologic study. Both the methods of interpretation are very important equally in order to find the possibility and limit of photogeologic interpretation. So, we interpret airphotographs qualitatively and quantitatively in this study. We found and traced lineaments on airphotographs in detail, and checked these interpretations in the field. Joints, faults and fractures were measured and mapped on the ground, and drainages were traced on the topographic map (1: 5, 000) . The above mentioned elements were graphed separately each other and compared numerically. Consequently, these data indicated that (1) an avarage of about 55% of the joint sets on the ground coincided with airphoto lineament sets, (2) about 70% of the faults and fractures coincided with the distribution and orientation of airphoto lineaments, and (3) drainage frequency and density changed clearly according to rock types.Although we can not jump to such the conclusion that these results will fit to everywhere because of the complex geological structure in Japan, we found, on these data, that the photogeologic interpretation was very useful. We hope our studies will give some suggestions to photogeologists.

Air-Photo Lineaments in Mpanda Area, Western Province, Tanganyika, Africa

An investigation was made of the occurrence of lineaments on air photographs in an area near Mpanda Western Tanganyika, Africa. A systematic analytical treatment was applied to these lineaments, various approaches being used, to see whether significant patterns or anomalies may be recognized. Variations observed in the density of lineaments per unit area appear to be attributable mainly to variations in the thickness of the soil cover but in one or two areas, it is considered that there may be some structural significance in this variation. The study showed that there is no simple regional lineament pattern in this part of Tanganyika, but that there are certain preferred lineament trends which appear to be related to Rift movements. A similarity was observed between the lineament pattern in the basement and that in the overlying Bukoban sediments and also between the pattern in two areas of different structural history within the Bukoban. It is suggested that one possible explanation of this may be found in repeated movements along old lines of weakness. The similarity between the basement and Bukoban lineament patterns may alternatively be explained by a large percentage of lineaments observed in the basement representing fractures of post-Bukoban age. It was discovered that the preferred trends are apparent only in plots of fairly large areas. Plots of small areas show no clear patterns; hence, it was not possible to distinguish local anomalies in pattern.