I GLOSSARY STRIKE SLIP DEFORMATION BASIN FORMATION AND SEDIMENTATION

KEVIN T BIDDLE Exxon Production Research Company P O Box 2189 Houston Texas 77252 2189

AND NICHOLAS CHRISTIE BLICK Departmelll of Geological and Lamolll Doherty Geological Observatory of Columbia University Palisades Nell York 10964

INTRODUCTION Basin l A site of pronounced accumulation 2 a relatively thick accumulation of sedimentary for Many of the geological terms having to do with strike a discussion of the history and usage of the word see Oen slip deformation basin formation and sedimentation are nis 1967 p 9 Bates and Jackson 1980 p 55 used in a variety of ways by different authors e g pull apart basin or they are synonymous with other words e g BubnofT curve A plot of subsidence versus time Fischer left lateral sinistral Rather than a enforcing rigorously 1974 uniform terminology in this book we decided to set down our preferred definitions in a glossary and where appro Bubnoff unit A standard measure of geologic rates such to indicate alternative usage In selecting terms for priate as subsidence rates defined as I m m y Fischer 1969 definition we have tried to steer a course between being Bates and Jackson 1980 p 84 overly encyclopedic and providing a list useful to those little familiarity with the of strike slip ba having Burial history curve A plot for a given location of the sins especially those described in this volume Some words cumulative thickness of overlying a surface ver e cycle have additional meanings in the geological sci g sus time Philipp 1961 van Hinte 1978 ences not included here and this glossary should therefore be used in the context of strike slip basins The references Closing bend See restraining bend cited are those from which we obtained definitions or which illustrate the concept embodied by a particular term We I The reduction in bulk volume or thick have not attempted to provide original references for every ness of or the pore space within a body of sediment in term especially for those long used in the geological lit to the increasing weight of a superimposed load erature response 2 the physical process by which fine grained sediment is converted to Bates THE GLOSSARY consolidated rock modified from and Jackson 1980 p 127 Anastomosing Pertaining to a network of branching and rejoining surfaces or surface traces Commonly used to de Compression I A system of stresses that tends to shorten scribe braided systems or decrease the volume of a substance preferred definition modified from Bates and Jackson 1980 130 Uniaxial Antithetic fault Originally defined by H Cloos 1928 p involves one nonzero stress which 1936 to describe faults that dip in a direction opposite to compression principal is in triaxial all three the dip of the rocks displaced and that rotate fault bounded compressive compression principal stresses are nonzero Means 1976 80 It is also blocks so that the net slip on each fault is greater than it p pos sible for a stress to occur with one would be without rotation Oennis 1967 p 3 Many au compressive principal or more tensile stresses 2 A state of strain in thors no use the term to describe faults that I are subsidiary principal which material lines become shorter under stress to a major fault and have less displacement than that fault compressive 1 T commun 1985 and Nur 2 formed in the same stress regime as the major fault with Engelder personal Aydin 1985 this volume see contraction which they are associated 3 are oriented at a high angle to the fault in map view for strike faults in major slip bend See bend cross sectional view for normal faults and 4 for strike Compressional restraining slip faults have a sense of displacement opposite that of Compressional overstep See restraining overstep the major fault or for normal faults dip in the opposite direction Antithetic strike faults the R set of up compose Conjugate Riedel shear Synonymous with R Riedel or Reidel shears formed in shear I simple Fig antithetic shear Fig I See Riedel shear synthetic and antithetic faults Aulacogen A term introduced by Shatski 1946a b to describe narrow elongate sedimentary basins that extend Contraction A strain involving I a reduction in volume into from either a or a mountain belt e g thermal contraction or 2 a reduction of length e g that formed from a geosyncline for a discussion of genesis contraction fault of Norris 1958 McClay 1981 Con in terms of see Hoffman et aI 1974 traction has been gaining popularity as the general strain term associated with compressive stress much like the re Lamont Doherty Geological Observatory Contribution No 3913 lationship between the stress term tension and the strain

Copyright @ 1985 The Society of Economic Paleontologists and Mineralogists 376 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK

ANTITHETIC SHEAR EXTENSION RIEDEl R SHEAR MASTER SECONDARY FAULT SYNTHETIC SHEAR SYNTHETIC TENSION T EN ECHElON SHEAR FRACTURE FOLDS

A B

ideal conditions from cake FIG I The angular relations between structures that tend to form in right lateral simple shear under compiled the in models and from geological examples Arrangements for structures along left slip faults may be determined by viewing figure reverse image deformation B Riedel shear modified A Terminology largely from Wilcox et al 1973 superimposed on a strain ellipse for the overall terminology from Tchalenko and Ambraseys 1970 and Bartlett el al 1981 See glossary for definitions of terms term extension The word shortening as used by Hobbs et Dip slip fault A fault along which most of the displace ment modified from Bates and al 1976 p 27 may be a better choice for general use is accomplished by dip slip because it does not imply a volume change Jackson 1980 p 177

Convergent bend A bend in a strike slip fault that results Divergent bend A bend in a strike slip fault that results in overall crustal shortening in the vicinity of the bend syn in overall crustal extension in the vicinity of the bend syn onymous with restraining bend of Crowell 1974a onymous with releasing bend of Crowell 1974a

Convergent overstep See restraining overstep Divergent overstep See releasing overstep

Convergent transpressional strike slip or wrench fault Divergent transtensional strike slip or wrench fault A strike slip or wrench fault along which strike slip defor A strike slip or wrench fault along which strike slip defor mation is accompanied by a component of shortening trans mation is accompanied by a component of extension trans verse to the fault Wilcox et aI 1973 verse to the fault Wilcox et aI 1973 Harding et aI 1985 this volume Cycle I An interval of time during which one series of recurrent events is completed preferred definition 2 a Downlap A base discordant relation in which initially in sequence of sediment or rock units repeated in a clined strata terminate downdip against an initially hori for additional discussion see Bates and Jackson 1980 p zontal or inclined surface Mitchum 1977 p 206 156 Drag I A fold produced by movement along a fault A of Depositional sequence stratigraphic unit composed see normal drag and reverse drag In this context the term a of related relatively conformable succession genetically is somewhat misleading because folding commonly ini strata and bounded at its and base or top by tiates before faulting Hobbs et aI 1976 p 306 2 A 206 their correlative conformities Mitchum 1977 p minor fold formed in a less competent bed between more competent beds by movement of the competent beds in op to dextral is Dextral Pertaining the right e g slip right posite directions relative to one another Bates and Jackson slip 1980 p 186

Dip The acute angle between an inclined surface and the fold A fold in a sedimentary layer that conforms horizontal measured in a vertical to Drape plane perpendicular to the of structures strike passively configuration underlying Friedman et aI 1976 p 1049 A fold formed by dif ferential compaction is an example of a drape fold Dip separation Separation measured parallel to the dip of a fault modified from Crowell 1959 p 2662 Bates The of kinematics and kinetics and Jackson 1980 p 177 See separation Dynamic analysis study that relates strains to the evolution of stress fields

Dip slip The component of slip measured parallel to the and dip of a fault Crowell 1959 p 2655 Bates and Jackson Echelon Step e g echelon faults of Clayton 1966 and faults 1980 p 177 See slip of Segall Pollard 1980 meaning overstepping GLOSSARY 377

En echelon I A stepped arrangement of relatively short synonymous with one usage of normal fault Suppe 1985 consistently overlapping or underlapping structural ele p 269 The term may be applied to faults of any dip ments such as faults or folds that are approximately parallel Christie Blick 1983 to each other but oblique to the linear or relatively narrow zone in which occur definition modified they preferred Extension fracture A mode I crack or one that shows from 1958 and Lowell 1979 see Campbell Harding Fig no motion in the plane of the crack Lawn and Wilshaw 2 En echelon arrangements can occur in both view map 1975 p 52 J T Engelder personal commun 1985 Ex and cross section Shelton 1984 and Nur 1985 this Aydin tension form when effective stresses are tensile volume 2 arrangement of two or more Any stepped i e when pore fluid pressure exceeds lithostatic pres or structural elements such as faults with T overlapping underlapping sure Partly synonymous fracture of Tchalenko and or folds that are to each other and approximately parallel Ambraseys 1970 See tension fracture In strike slip sys to which without reference to whether the zone in they occur tems extension fractures and tension fractures form in re the sense of overstep is consistent or inconsistent e g for at sponse to simple shear about 450 to the master fault Fig deformation OA 1980 and strike slip Rodgers Aydin I Nur 1985 this volume for thrust and fold belts J Rod 1963 Armstrong 1968 Oahlstrom 1970 See oblique gers Extensional bend See releasing bend relay pattern

Extensional See Extension A strain involving an increase in length overstep releasing overstep

Extension fault A fault that results in lengthening of an External rotation A change in the orientation of struc arbitrary datum commonly but not necessarily bedding tural features during deformation with reference to coor

EN ECHELON RELAY LEFT STEPPING RIGHT STEPPING

a 17 o

HORSETAIL RESTRAINING RELEASING OVERSTEP SPLAY BEND BEND

FIG 2 Some simple structural patterns 378 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK dinate axes external to the deformed body Bates and Jack Fracture zone An extension of a transform fault beyond son 1980 p 218 its intersection with an oceanic ridge Fracture zones are characterized by dip slip especially where juxtaposed oceanic different and do not I Laterally or sequentially associated bodies of is of markedly age usually they strike Freund 1974 Fox and Gallo sediment or distinguished on the basis of experience slip see 1984 objective lithologic and paleontologic characteristics that reflect the processes and environments of and An block bounded or 2 distinctive adjacent coeval rock units elongate relatively depressed normal faults Bates and Jackson 1980 268 White 1980 3 the lithologic and paleontologic char by p acteristics of a body of sediment or sedimentary rock that Heat flow The product of a thermal gradient and the ther reflect the processes and environments of deposition orig mal conductivity of the material across which the thermal inal sense of Gressly 1838 See Walker 1984 for further is measured discussion and references to numerous reviews gradient

Horsetail One of a set of curved fault near Fault angle depression A subsiding depression parallel splay splays the end of a strike fault that with that fault The to the trace of an oblique slip fault Ballance 1980 p 232 slip merge set forms an array that crudely resembles a horse s tail Figs Fault flank depression A depression between subsidiary 2 3 folds of a strike slip fault system Crowell 1976 Internal rotation A change in the orientation of struc Fault slice ridge A linear topographic high associated with tural features during deformation with reference to coor Bates and a fault bounded uplifted block within a fault zone Crowell dinate axes internal to the deformed body Jack son 322 1974b synonymous with pressure ridge 1980 p

The Fault splay A subsidiary fault that merges with and is Kinematic analysis analysis of a movement pattern stress genetically related to a more prominent fault Fault splays based on displacement without reference to force or are common near the termination of a major strike slip fault modified from Spencer 1977 p 39 Fig 2 unless this is at an intersection with another strike slip fault Leaky transform A transform plate boundary character ized by significant volcanism and or intrusion along its Fault strand An individual fault of a set of closely spaced length See Garfunkel 1981 for a continental example See parallel or subparallel faults of a fault system transform fault transform margin

Fault wedge basin A basin formed by extension at a re Left hand overstep or stepover An overstep stepover leasing junction between two predominantly strike slip faults in which one fault or fold segment occurs to the left of the having the same sense of offset Crowell 1974a synony adjacent segment from which it is being viewed Campbell mous with wedge graben of Freund 1982 See releasing 1958 Wilcox et aI 1973 See left stepping overstep fault in junction stepover For oversteps cross section it is necessary to specify the direction from which the overstep is being viewed Flexure I A fold produced by a force couple applied to the direction of deflection 1985 360 parallel Suppe p Left lateral Refers to an offset along a fault in map view 2 a mechanism of regional isostatic compensation in which in which the far side is apparently displaced to the left with loads are broad deflection of the supported by lithosphere respect to the near side as a result of lithospheric rigidity Watts and Ryan 1976 Watts 1983 M S Steckler commun 1985 personal Left separation Strike separation in which the far side of a fault is apparently displaced to the left with respect to Flower structure An array of upward diverging fault the near side See separation strike separation splays within a strike slip zone attributed to R F Gregory by Harding and Lowell 1979 see positive flower structure Left slip The component of slip measured parallel to the and negative flower structure synonymous with palm tree strike of a fault in which the far side of the fault is displaced structure of Sylvester 1984 but preferred for reasons of to the left with to the near side See precedence respect slip

Left Refers to an in which one fault Forced fold A fold whose overall shape and trend are stepping overstep to dominated by the shape and trend of an underlying forcing or fold segment occurs the left of the adjacent segment member Stearns 1978 from which it is being viewed Fig 2 See left hand over step Foreland A more or Iess stable area underlain by conti nental crust and adjacent to an orogenic belt toward which Lineament A linear topographic feature of regional ex rocks of the belt were tectonically transported Bates and tent that is thought to reflect crustal structure Hobbs et aI 241 Jackson 1980 p 1976 p 267 GLOSSARY 379

DElAIL OF POZ

RELEASING BEND

I I AREAS OF SUBSIDENCE

PRINCIPAL DISPLACEMENT ZONE POZ

FIG 3 The spatial arrangement in map view of structures associated with an idealized right slip fault See glossary for definitions of terms

Listric fault A curved generally concave upward slip faults new term See overstep overlap and under downward flattening fault see Bally et aI 1981 Listric lapping faults faults may be characterized by normal or reverse separa tion Negative flower structure A flower structure in which the upward diverging fault splays are predominantly of nor Lithosphere The outer shell of the Earth consisting of mal separation and commonly associated with a prominent structure or structures in strata above or cut crust and upper and characterized by strength rel synformal by the et this ative to the underlying for deformation at faults Harding 1983 1985 Harding aI 1985 volume See flower structure geologic rates Bates and Jackson 1980 p 364 Watts 1983 The base of the lithosphere can be defined by a Net The vector connecting formerly number of different properties that reflect rheology such slip displacement on sides of a fault modified from as temperature seismic velocity and degree of seismic at adjacent points opposite Hobbs et aI 1976 300 tenuation p

Normal Folding near a fault resulting from resis the drag Marginal basin A semi isolated basin lying behind to tance to slip along the fault Folded strata are convex volcanic chain ofan system Karig 1971 p 2542 ward the slip direction on both sides of the fault See drag fold Master fault A major fault in a fault system Wilcox et aI 1973 Rodgers 1980 nearly synonymous with prin Normal fault I A fault with normal separation across and 1970 cipal displacement zone ofTchalenko Ambraseys which the hanging wall is apparently lowered with respect to the footwall preferred definition Hill 1959 2 a fault A Megashear strike slip fault with horizontal displace generated by normal slip see Gill 1941 1971 The term ment exceeds the thickness of the crust that significantly may be applied to faults of any dip Christie Blick 1983 Carey 1958 1976 p 85 Normal separation Separation measured parallel to the Multiple overstep A series of discontinuities between dip of a fault across which the hanging wall is apparently approximately parallel overlapping or underlapping strike lowered with respect to the footwall See separation 380 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK

Normal slip The component of slip measured parallel to P shear One of a set of faults that develop in simple shear the dip of a fault across which the hanging wall is lowered generally after the formation of Riedel shears P shears have with respect to the footwall See slip the same sense of displacement as Riedel R shears and form at an angle to the principal displacement zone that is Oblique Not parallel intersecting at an acute angle En of about the same magnitude but of opposite sign Skemp echelon elements are oblique to the zone in which they oc ton 1966 Tchalenko and Ambraseys 1970 Figs I 3 cur but not all oblique elements are en echelon See en Synonymous with secondary synthetic strike slip fault echelon Piercing points The points of intersection of formerly Oblique slip The relative displacement of formerly ad contiguous linear features real or constructed on opposite jacent points on opposite sides of a fault involving com sides of a fault by means of which net slip on the fault ponents of both dip slip and strike slip See slip dip slip may be determined Crowell 1959 p 2656 Examples of strike slip such linear features are the pinchout line of a sedimentary wedge offset streams and facies boundaries used in con Oblique slip fault A fault along which displacement is junction with structure contours accomplished by a combination of strike slip and dip slip See slip oblique fault Plunge The acute angle between an inclined line and the horizontal measured in a vertical plane containing the line Oblique subduction The relative displacement of one lithospheric plate beneath another plate such that in map Pop up A relatively uplifted block between thrusts verg view the displacement vector is oblique to the plate bound ing in opposite directions Originally applied to structures and ary in thrust fold belts Butler 1982

On lap A base discordant stratigraphic relation in which Positive flower structure A flower structure in which the initially horizontal or inclined strata terminate updip against upward diverging fault splays are predominantly of reverse an initially inclined surface modified from Mitchum 1977 separation and commonly associated with a prominent an p 208 tiformal structure or structures in strata above or cut by the faults Harding et aI 1983 Harding 1985 See flower Opening bend See releasing bend structure

Orogeny Profound deformation of rock bodies along re Pressure ridge A linear topographic high associated with stricted zones and within a limited time interval Oennis a fault bounded uplifted block within a fault zone Tcha 112 1967 p lenko and Ambraseys 1970 synonymous with fault slice ridge Overlap I The distance between the ends of overlap ping parallel faults measured parallel to the faults Rod Principal displacement zone A relatively narrow zone gers 1980 Mann et aI 1983 Aydin and Nur 1985 this that accounts for most of the slip on a given fault Tcha volume generally applied to strike slip faults in map view lenko and Ambraseys 1970 p 43 Fig 3 See master nearly synonymous with separation of Segall and Pollard fault 1980 2 a relation between two superimposed strati graphic units onlapping a given surface in which the upper Progradation The outward building of sediment in the unit extends beyond the line of pinch out in the lower unit direction of transport generally but not exclusively from a shoreline toward a body of water Overstep I a discontinuity between two approximately 2 parallel overlapping or underlapping faults Fig syn Pull apart basin I A basin formed by crustal extension onymous with stepover of Aydin and Nur 1982a b 1985 at a releasing bend or releasing overstep along a strike slip this volume Oversteps can occur in both map view and fault zone preferred definition Burchfiel and Stewart 1966 cross section and on both strike slip and dip slip faults Crowell 1974b Mann et aI 1983 nearly synonymous with Nur Aydin and 1985 this volume but the term is com rhomb graben 2 any basin resulting from crustal exten monly applied to strike slip faults in map view See solitary sion Klemme 1980 Bois et aI 1982 overstep multiple overstep releasing overstep and re straining overstep 2 A stratigraphic relation in which one Pure shear A homogeneous deformation involving either or more stratigraphic units unconformably overlie the eroded a plane strain or a general strain in which lines of particles edge of older generally tilted or folded sedimentary rocks that are parallel to the principal axes of the strain ellipsoid have the same orientation before and after deformation Palm tree structure An array of upward diverging fault Hobbs et aI 1976 p 28 Also referred to as an irrota splays within a strike slip zone nomenclature of A G tional deformation or strain See shear simple shear RR Sylvester and Smith Sylvester 1984 synonymous structure with flower of Harding and Lowell 1979 a term Push up A block elevated by crustal shortening at a re that has precedence straining bend or restraining overstep along a strike slip fault GLOSSARY 381

Nur Mann aI See zone Aydin and 1982a et 1983 rhomb Reverse fault I A fault with reverse separation across which the hanging wall is apparently elevated with respect to the footwall preferred definition Hill 1959 2 a fault Ramp valley A topographic basin bounded by reverse generated by reverse slip see Gill 1941 1971 The term faults Burke et aI Not all be Willis 1928 p 493 1982 may applied to faults of any dip Christie Blick 1983 ramp valleys are related to strike slip deformation Reverse separation Separation measured parallel to the Regression A seaward retreat of a shoreline generally dip of a fault across which the hanging wall is apparently expressed as a seaward migration of shallow marine facies elevated with respect to the footwall See separation modified from Mitchum 1977 p 209 Reverse slip The component of slip measured parallel to the of a fault across which the wall is elevated Relay pattern A shingled arrangement of inconsistently dip hanging with to the footwall See overlapping or underlapping structural elements such as faults respect slip or folds that are approximately parallel to each other and Rhombochasm A parallel sided gap in sialic continen to the elongate zone in which they occur modified from tal crust occupied by simatic oceanic crust modified from Harding and Lowell 1979 Fig 2 Many authors do not Carey 1976 p 81 One of S W Carey s distinguish between en echelon and arrangements See type examples relay is the Gulf of California For definition and dis Christie Blick and Biddle I985 this volume original cussion see Carey 1958

Releasing bend A bend in a strike slip fault associated Rhomb graben A basin formed by crustal extension at with overall crustal extension in the vicinity of the bend a releasing bend or releasing overstep in a strike slip fault Figs 2 3 Crowell 1974a synonymous with divergent zone Freund 1971 and Nur 1982b synonymous bend Aydin with pull apart basin of Burchfiel and Stewart 1966 and Crowell 1974a b particularly sharp pull aparts or ones fault A between two strike in view Releasing junction junction that are angular map slip faults associated with overall crustal extension and ba sin formation between the faults Christie Blick and Biddle Rhomb horst A block elevated by crustal shortening at 1985 this volume See fault wedge basin wedge graben a restraining bend or restraining overstep in a strike slip fault zone Aydin and Nur 1982b nearly synonymous with of and Nur 1982a and Mann et Releasing overstep A right overstep between right slip push up Aydin aI 1983 in faults or a left overstep between left slip faults associated particularly those that are angular map view with overall crustal extension and basin formation between the faults Christie Blick and Biddle 1985 this volume Riedel shear In simple shear two sets of shear fractures tend to form oriented at 1 2 and 900 1 2 to the principal displacement zone where I is the internal coefficient of Restraining bend A bend in a strike slip fault associated friction commonly taken to be about 300 Shear fractures with overall crustal shortening and uplift in the vicinity of oriented at 1 2 are called R shears whereas those formed the bend Figs 2 3 Crowell 1974a synonymous with at 900 1 2 are termed R shears modified from Tchalenko convergent bend and Ambraseys 1970 See synthetic and antithetic faults Figs I 3 Restraining fault junction A junction between two strike faults associated with overall crustal and slip shortening uplift Right hand overstep or stepover An overstep step between the faults Christie Blick and Biddle 1985 this over in which one fault or fold segment occurs to the right volume of the adjacent segment from which it is being viewed Campbell 1958 Wilcox et aI 1973 See right stepping Restraining overstep A right overstep between left slip overstep stepover For oversteps in cross section it is nec faults or a left overstep between right slip faults associated essary to specify the direction from which the overstep is with overall crustal shortening and uplift between the faults being viewed Christie Blick and Biddle 1985 this volume Right lateral Refers to an offset along a fault in map view in which the far side is apparently displaced to the right Retrogradation The landward backstepping of sedimen with respect to the near side tary units usually but not exclusively from a shoreline as expressed a landward of facies belts by migration Right separation Strike separation in which the far side of a fault is apparently displaced to the right with respect a that Reverse drag Oeformation along fault creates a to the near side See separation strike separation fold or set of folds whose curvature is opposite that which would be formed by normal drag folding Reverse drag is Right slip The component of slip measured parallel to a common feature of listric normal faults where hanging the strike of a fault in which the far side of the fault is wall folds are concave toward the slip direction displaced to the right with respect to the near side See slip 382 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK

Right stepping Refers to an overstep in which one fault Slip The relative displacement of formerly adjacent points the surface or fold segment occurs to the right of the adjacent segment on opposite sides of a fault measured along fault from which it is being viewed Fig 2 See right hand over modified from Reid et aI 1913 p 168 Crowell 1959 step p 2655

Rotation Motion in which the path of a point in the mov Slip oblique fault A strike slip fault along which strike of either ing object defines an arc around a specified axis slip deformation is accompanied by a component shortening or extension transverse to the fault Mann et al Rotational strain Strain in which the orientation of the 1983 includes convergent and divergent strike slip or wrench et and trans strain axes is different before and after deformation Bates faults of Wilcox aI 1973 and transpressional with and Jackson 1980 p 546 See simple shear tensional faults of Harland 1971 nearly synonymous oblique slip fault Secondary synthetic fault One of a set of faults that de fault A fault that strikes parallel to the azi velop in simple shear generally after the formation of syn Slip parallel muth of the direction Mann et aI 1983 thetic faults Riedel shears Secondary synthetic faults have slip synonymous with strike or wrench fault of Wilcox the same sense of displacement as the synthetic faults and simple parallel slip et aI 1973 and with strike fault of Christie form an angle to the principal displacement zone that is of simple slip Blick and Biddle 1985 this volume about the same magnitude as the synthetic faults but of op posite sign Figs I 3 Synonymous with P shear See An isolated between two synthetic and antithetic fault Riedel shear Solitary overstep discontinuity approximately parallel overlapping or underlapping faults Guiraud and Seguret 1985 this volume Fig 2 Separation I The apparent displacement of formerly contiguous surfaces on opposite sides of a fault measured Sphenochasm A triangular gap of oceanic crust separat in any given direction modified from Reid et aI 1913 p ing two continental blocks with fault margins converging 169 Crowell 1959 p 2661 2 the perpendicular dis to a and as originated the ro tance between strike slip faults Rod point interpreted having by overlapping parallel to the other modified from and Nur this tation of one block with respect gers 1980 Mann et aI 1983 Aydin 1985 1976 81 The of Biscay is one of S W volume 3 the distance between overstepping parallel strike Carey p Bay s of a sphenochasm See Carey 1958 for slip faults either overlapping or underlapping measured Carey examples original definition parallel to the faults Segall and Pollard 1980 nearly syn onymous with overlap of Rodgers 1980 Splay Generally synonymous with fault splay a subsid to iary fault that merges with and is genetically related a Shear A strain resulting from stresses that cause or tend more prominent fault to cause parts of a body to move relatively to each other in a direction parallel to their plane of contact modified Stepover A discontinuity between two approximately from Bates and Jackson 1980 p 575 See pure shear parallel overlapping or underlapping faults Aydin and Nur simple shear 1982a b 1985 this volume Aydin and Page 1984 syn onymous with overstep Stepovers can occur in both map shear A constant volume defor Simple homogeneous view and cross section and on both strike slip and dip slip mation strain in which a of involving plane single family faults Aydin and Nur 1985 this volume but the term is material is undistorted in the deformed state parallel planes commonly applied to discontinuities on strike slip faults in and to the same of in the undeformed parallel family planes map view state Hobbs et aI 1976 p 29 Also referred to as a ro tational deformation or strain See shear shear pure Stratigraphic separation The stratigraphic thickness either cut out or repeated by a fault modified from Crowell 1959 A wrench Simple strike slip or wrench fault strike slip or p 2663 fault along which adjacent blocks move laterally with no component of shortening or extension transverse to the fault Strand See fault strand Christie Blick and Biddle 1985 this volume synonymous with simple parallel strike slip or wrench fault of Wilcox Strike The azimuth of the line of intersection of an in et aI 1973 and with slip parallel fault of Mann et aI clined surface with a horizontal plane 1983 Strike separation Separation measured parallel to the strike 2662 Bates Sinistral Pertaining to the left e g sinistral slip is left of a fault modified from Crowell 1959 p slip and Jackson 1980 p 618 See separation

to A polished or smoothly striated surface on Strike slip The component of slip measured parallel Bates either side of a fault that results from motion along the fault the strike of a fault Crowell 1959 p 2655 and Bates and Jackson 1980 p 587 Jackson 1980 p 618 See slip GLOSSARY 383

Strike slip fault A fault along which most of the dis Thermal subsidence That part of the tectonic subsidence placement is accomplished by strike slip modified from at a given point in a caused by thermal Bates and Jackson 1980 p 618 contraction Sleep 1971 Parsons and Sclater 1977 See tectonic subsidence Strike slip basin Any basin in which sedimentation is accompanied by significant strike slip modified from Mann A map scale contraction fault that shortens et aI 1983 an arbitrary datum commonly but not necessarily bedding McClay 1981 The term may be applied to faults of any Subsidence The depression of an area of the Earth s crust dip although thrust faults tend to dip less than 300 during with respect to surrounding areas active slip

Synthetic fault Originally defined by H Cloos 1928 Trace slip The component of slip measured parallel with 1936 to describe faults that dip in the same direction as the trace of a bed or other surface on the fault plane the rocks displaced and that rotate fault bounded blocks so Reid et aI 1913 p 170 Beckwith 1941 p 2182 that the net slip on each fault is less than it would be with I out rotation Oennis 1967 p 148 149 Many authors now Transcurrent fault A strike slip fault typically sub use the term to describe faults that I are subsidiary to a vertical at depth and commonly involving igneous and major fault and have less displacement than that fault 2 metamorphic as well as supracrustal sediments formed in the same stress regime as the major fault with and sedimentary rocks see Moody and Hill 1956 Freund which they are associated 3 are oriented at a low angle 1974 nearly synonymous with wrench fault 2 a long to the major fault in map view for strike slip faults in subvertical strike slip fault that cuts strata approximately cross sectional view for normal faults and 4 for strike perpendicular to strike original sense of Geikie 1905 p slip faults have the same sense of displacement as the ma 169 modified from Oennis 1967 p 57 jor fault with which they are associated or for normal faults dip in the same direction The R set of Riedel shears and Transform fault A strike slip fault that acts as a litho the P shears of Tchalenko and Ambraseys 1970 are syn spheric plate boundary and terminates at both ends against thetic faults Figs I 3 major tectonic features such as oceanic ridges subduction zones or rarely other transform faults that are also plate Tear fault A strike slip or oblique slip fault within or boundaries Wilson 1965 Freund 1974 bounding an produced by either regional exten sion or regional shortening Tear faults accommodate dif Transform margin A plate margin formed by a trans ferential displacement within a given allochthon or be form fault or system of transform faults and dominated by tween the allochthon and adjacent structural units strike slip deformation

Tectonic depression I Any structurally produced to Transgression A landward movement of a shoreline pographic low 2 a topographic low produced by strike generally expressed as a landward migration of shallow slip deformation Clayton 1966 marine facies modified from Mitchum 1977 p 211

Tectonic subsidence That part of the subsidence at a given Transtension A system of stresses that operates in zones point in a sedimentary basin caused by a tectonic driving of oblique extension modified from Harland 1971 See mechanism Tectonic subsidence is calculated by removing divergent strike slip or wrench fault transpression the component of subsidence produced by non tectonic pro cesses such as sediment loading sediment compaction and Transpression A system of stresses that operates in zones water depth changes Watts and Ryan 1976 Steckler and of oblique shortening modified from Harland 1971 Watts 1978 Keen 1979 Bond and Kominz 1984 Sylvester and Smith 1976 See convergent strike slip or wrench fault transtension Tension A system of stresses that tends to lengthen or increase the volume of a substance Uniaxial tension in Trend The azimuth of an inclined or horizontal line volves one nonzero principal stress which is tensile in general tension two principal stresses are tensile Means A buried surface of or non de It stress to 1976 p 79 is possible for a tensile principal position modified from J C Crowell personal commun occur with one or more compressive principal stresses 1975

Tension T fracture A mode I crack that forms when Underlapping faults Approximately parallel faults that lithostatic loads become negative Lawn and Wilshaw 1975 overstep without overlapping applied to oceanic ridge seg See p 52 J T Engelder personal commun 1985 ex ments by Pollard and Aydin 1984 tension fracture In strike slip systems extension fractures and tension fractures form in response to simple shear at Wedge graben A basin formed by extension at a releas about 450 to the master fault Fig I Tchalenko and Am ing junction between two predominantly strike slip faults braseys 1970 having the same sense of offset Freund 1982 synony 384 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK mous with fault wedge basin of Crowell 1974a See re Rocky Mountains Implications for subsidence mechanisms age of leasing fault junction breakup and crustal thinning Geological Society of America Bulletin v 95 p 155 173 BURCHFIEL B c AND STEWART 1 H 1966 Pull apart origin of the A at Wrench fault strike slip fault typically sub vertical central segment of Death Valley California Geological Society of depth involving igneous and metamorphic basement rocks America Bulletin v 77 p 439 442 BURKE K MANN P KIDD W 1982 What is as well as supracrustal sediments and sedimentary rocks AND a ramp valley 11th Intcrnational Congress on Hamilton Ontariu In modified from Moody and Hill 1956 p 1208 Wilcox et tcrnational Association of Sedimentologists Abstracts of Papers p 40 aI 1973 with transcurrent fault nearly synonymous BUTLER R W H 1982 The terminology of structures in thrust belts Journal of v 4 p 239 245 CAMPBELL J D 1958 En echelon Economic v 53 Y shear A fault that forms in response to simple shear folding Geology 448 472 and as deformation continues gradually accommodates most p CAREY S W 1958 A tectonic approach to in Carey of the movement the zone Drift a Hobart along principal displacement S W convenor Continental Symposium University et Bartlett aI 1981 uf Tasmania 177 355 1976 The Expanding Earth Amsterdam Elsevier Scientific Publishing Company Developments in Geotectonics 10 488 p ACKNOWLEDGMENTS CHRISTIE BLICK N 1983 Structural geology of the southern Sheeprock Mountains Utah Regional significance in Miller D M Todd V In compiling this glossary we have been inspired by J R and Howard KA eds Tectonic and Stratigraphic Studies in C Crowell s insistence on the value of precise terminology the Eastern Great Basin Geological Society of American Memoir 157 for the effective communication of both observations and p 101 124 CHRISTIE BLICK N AND BIDDLE K T 1985 Deformation and basin for ideas The was reviewed at various stages manuscript by mation along strike slip faults in Biddle K T and Christie Blick A J T A M Grunow O R Aydin Engelder Seely N eds Strike Slip Deformation Basin Formation and Sedimenta and CC Wielchowsky We also thank IW O Oalziel tion Society of Economic Paleontologists and Mineralogists Special KA Kastens C Nicholson and M S Steckler for help Publication 37 p 1 34 CLA YTON L 1966 Tectonic the Fault a trans ful suggestions Remaining errors or omissions are how depressions along Hope current fault in North Canterbury New Zealand New Zealand Journal ever the of the authors support responsibility Logistical of Geology and v 9 p 95 104 was provided by Exxon Production Research Company and CLOOS H 1928 Ober antithetische Bewegungen Geologische Rund by an ARCO Foundation Fellowship to Christie Blick schau v 19 p 246 251 1936 Einfiihrung in die Geologie Berlin Borntraeger 503 p CROWELL J C 1959 Problems of fault nomenclature American As REFERENCES sociation of Bulletin v 43 p 2653 2674 1974a Origin of late basins in southern California in ARMSTRONG R L 1968 Sevicrorogenic belt in Nevada and Utah Geo Dickinson W R ed Tectonics and Sedimentation Society of Eco and Publication No 22 logical Society of America Bulletin v 79 p 429 458 nomic Paleontologists Mineralogists Special AYDIN A AND NUR A 1982a Evolution of pull apart basins and push p 190 204 1974b Sedimentation the San Andreas fault California up ranges Pacific Petroleum Geologists Newsletter American Asso along Dott R H Jr and Shaver R H eds Modem and Ancient ciation of Petroleum Geologists Pacific Section Nov 1982 p 2 4 in 1982b Evolution of pull apart basins and their scale indepen Geosynclinal Sedimentation Society of Economic Paleontologists and dence Tectonics v I p 91 105 Mineralogists Special Publication No 19 p 292 303 1985 The types and role of stepovers in strike slip tectonics 1976 Implications of crustal stretching and shortening of coastal in Biddle K T and Christie Blick N Strike Slip Deformation Ba Ventura Basin California in Howell DG ed Aspects of the Geo sin Formation and Sedimentation Society of Economic Paleontolo logic History of the California Continental Borderland American As gists and Mineralogists Special Publication No 37 p 35 44 sociation of Petroleum Geologists Pacific Section Miscellaneous Pub AYDIN A AND PAGE B M 1984 Diverse tec lication 24 p 365 382 tonics in a transform environment San Francisco Bay region Cali DAHLSTROM C DA 1970 Structural geology in the eastern margin of fornia Geological Society uf Amcrica Bulletin v 95 p 1303 1317 the Canadian Rocky Mountains Bulletin of Canadian Petroleum Ge BALLANCE PF 1980 Models of sediment distribution in non marine ology v 18 p 332 406 American and shallow marine cnvironments in oblique slip fault zones ill Bal DENNIS 1 G ed 1967 International Tectonic Dictionary lance PF and Reading H G cds Sedimentation in Oblique Slip Association of Petroleum Geologists Memoir 7 196 p Mobile Zones International Association of Sedimentologists Spccial FISCHER AG 1969 Geologic time distance rates the Bubnoff unit Bulletin v 80 549 551 Publication No 4 p 229 236 Geological Society of America p BALLY A W BERNOULLI D DAVIS GA AND MONTADERT L 1981 1974 Origin and growth of basins in Fischer AG and Jud Listric Global Tectonics Princeton New normal faults Oceanologica Acta Proceedings 26th Interna son S ed Petroleum and Jersey tional Geological Congress Geology of Continental Margins Sympo Princeton University Press p 47 82 sium Paris p 87 101 Fox PJ AND GALLO D G 1984 A tectonic model for ridge trans BARTLETT W L FRIEDMAN M AND LOGAN J M 1981 Experimental form ridge plate boundaries Implications for the structure of oceanic folding and faulting of rocks under confining pressure Part IX Wrench lithosphere v 104 p 205 242 faults in layers Tectonophysics v 79 p 255 277 FREUND R 1971 The Hope Fault a strike slip fault in New Zealand BATES R L AND JACKSON J A 1980 eds New Zealand Bulletin v 86 p 1 49 American Geological Institute 749 p 1974 Kinematics of transform and transcurrent faults Tecton BECKWITH R H 1941 Trace slip faults American Association of Pe ophysics v 21 p 93 134 troleum Geologists Bulletin v 25 p 2181 2193 1982 The role of shear in rifting in Pilmason G ed Con BOIS c BOUCHE P AND PELET R 1982 Global geologic history and tinental and Oceanic American Geophysical Union distribution of reserves American Association of Petro Series v 8 p 33 39 leum Geologists Bulletin v 66 p 1248 1270 FRIEDMAN M HANDIN J LOGAN J M MIN KD AND STEARNS D BOND G c AND KOMINZ M A 1984 Construction of tectonic sub W 1976 Experimental folding of rocks under confining pressure Part sidence curves for the early miogeocline southern Canadian III Faulted drape folds in multilithologic layered specimens Geolog GLOSSARY 385

ical of America Bulletin v 87 p 1049 1066 C Seismic to Society Payton E cd Applications Hydrocar GARFUNKEL Z 1981 Internal structurc of the Dead Sea lcaky transfurm bon Exploration American Association of Petroleum Geologists Mem in relation tu platc kincmatics Tectonophysics v 80 p 81 108 oir 26 p 205 212 GEIKIE J 1905 Structural and Field Geology Edinburgh Oliver and MOODY J D AND HILL M L 1956 Wrench fault tectonics Geolog v Boyd 435 p ical Society of America Bulletin 67 p 1207 1246 GILL J E 1941 Fault nomenclature Royal Society of Canada Trans NORRIS DK 1958 Structural conditions in Canadian mines Geo actions v 35 p 71 85 logical Survey of Canada Bulletin 44 54 p 1971 Continued confusion in the classification of faults Geo PARSONS AND SCLATER J 1977 An of the variation of B G analysis floor flow with logical Society of America Bulletin v 82 p 1389 1392 ocean bathymetry and heat age Journal of Geophysical GRESSL Y A 1838 Observations geologique sur Ie Jura Soleurois Nou Research v 82 p 803 827 veaux Memoires de la Societe Helvetique des Sciences Naturelles v PHILIPP w 1961 Struktur und Lagerstattengeschichte des Erdolfeldes Gesellschaft v 2 p 1 112 Eldingen Deutsche Geologische Zeitschrift 112 p GUIRAUD M AND SEGUREr M 1985 A releasing solitary overstep model 414 482 for the late Cretaceous Wealdian Soria strike ba POLLARD DD AND AYDIN 1984 and of oceanic early slip A Propagation linkage sin northern ill Biddle K T and Christie Blick N scgments Journal of Research v 89 p 10 017 Spain cds ridge Geophysical Strike Slip Deformation Basin Formation and Sedimentation Society 10 028 of Economic and Publication No REItJ H et al 1913 of the Committee on the Nomenclature Palcontologists Mineralogists Special F Report of Faults of America Bulletin v 24 163 186 37 p 159 177 Geological Society p HARDING T P 1983 Divergent wrench fault and negative f10wcr struc RODGERS DA 1980 Analysis of pull apart basin development pro ture Andaman Sea i1 A W cd Seismic of Struc duced en echelon strike faults ill Ballance P and Bally Expression by slip F Reading tural v 3 American Association of Petroleum Stud H cds Sedimentation in Mobile Zones Interna Styles Geulogists G Oblique Slip ies in Geology Series 15 v 3 p 4 2 1 to 4 2 8 tional Association of Scdimentulogists Special Publication No 4 p 1985 Seismic characteristics and idcntification of negative flower 27 41 structures positive flower structures and positive structural inversion RODGERS 1 1963 Mechanics of Appalachian foreland folding in Penn American Association Petroleum Geologists Bulletin v 69 p 582 sylvania and West Virginia American Association of Petroleum Ge 600 ologists Bulletin v 47 p 1527 1536 HARIJING TP AND LOWELL J 1979 Structural their SEGALL P AND POLLARD D 1980 Mechanics of discontinuous faults D styles plate D tectonic habitats and hydrocarbon traps in petroleum provinces Amcr Journal of Geophysical Research v 85 p 4337 4350 ican Association of Petroleum Gcologists Bulletin v 63 p 1016 SHATSKI N S 1946a Basic features of the structurcs and development 1058 of the East European platform Comparative tectonics of ancient plat HARDING TP GREGORY RF AND STEPHENS L H 1983 Convergent forms Izvestiya Akademii Nauk SSSR Ser Geol No I p 5 62 wrench fault and positive flower structure Ardmore Basin Oklahoma 1946b The Great Donets Basin and the Wichita System Com i1 A W Seismic of Structural v 3 tectonics of ancient Akademii Nauk SSSR Bally cd Expression Stylcs parative platforms Izvestiya American Association of Petroleum Geologists Studics in Gculogy Sc Ser Geol No 6 p 57 90 ries 15 4 2 13 to 4 2 17 SHELTON J 1984 Listric normal faults An illustrated summary p W HARDING T P VIERBUCHEN R C AND CHRISTIE BLICK 1985 American Association of Pctroleum Bulletin v 68 p 801 N Geologists Structural styles platc tectonic settings and hydrocarbon traps of di 815 transtensional wrench faults ill Biddle K and Christic SLEEP NH 1971 Thermal effects of the formation of Atlantic conti vergent T Blick eds Strike Deformation Basin Formation and Sedi nental continental Astronomical N Slip margins by breakup Royal Society mentation Society of Economic Paleontologists and Mineralogists Spe Geophysical Journal v 24 p 325 350 cial Publication No 37 p 51 78 SKEMPTON A W 1966 Some observations on tectonic shear zones 1st HARLAND W B 1971 Tectonic transpression in Caledonian Spitsber Congress of International Society of Rock Mechanics Lisbon Pro gen Geological Magazine v 108 p 27 42 ceedings v I p 329 335 HILL M L 1959 Dual classification of faults American Associatiun SPENCER E 1977 Introduction to the Structure of the Earth New W of Petroleum Gcologists Bulletin v 43 p 217 237 York McGraw Hill Book Company 2nd edition 640 p forced in HOBBS B E MEANS W D AND WILLIAMS P F 1976 An Outline STEARNS D W 1978 Faulting and folding thc Rocky Moun of Structural Geology New York John Wiley and Sons 571 p tains foreland in Matthews V Ill ed Laramide Folding Associated HOFFMAN P DEWEY J F AND BURKE K 1974 Aulacogens and their With Basement Block Faulting in the Western United States Geolog ical of America Memoir 151 37 genetic relation to with a Proterozoic example from Great Society p 1 Slave Lake Canada in Dott R Jr and Shaver RH STECKLER M S AND WATTS A B 978 Subsidence of the Atlantic H eds Modern and Ancient Geosynclinal Sedimentation Society of Economic type off New York Earth and Planetary Paleontologists and Mineralogists Special Publication No 19 p 38 Letters v 41 p 1 13 55 SUPPE J 1985 Principles of Structural Geology Englewood Cliffs New KARIG D E 1971 Origin and development of marginal basins in the Jersey Prenticc Hall 537 p Wrench Fault Tectonics American western Pacific Journal of Geophysical Research v 76 p 2542 2561 SYLVESTER AG compiler 1984 Series No 374 KEEN C E 1979 Thermal history and subsidence of rifted continental Association of Petroleum Geologists Reprint 28 p margins Evidence from wells on the Nova Scotian and Labrador SYLVESTER AG AND SMITH RR 1976 Tectonic transpression and Shelves Canadian Journal of Earth Sciences v 16 p 505 522 basement controlled deformation in the San Andreas fault zone Saltun KLEMME H 1980 Petroleum basins c1assificatiuns and character Trough California American Association of Petroleum Geologists D istics Journal uf Petroleum Geology v 3 p 187 207 Bulletin v 60 p 2081 2102 LAWN BR AND WILSHAW T R 1975 Fracture of Brittle Solids New TCHALENKO JS AND AMBRASEYS NN 1970 Structural analysis of York Cambridge University Press 204 p the Dasht e Bayaz Iran fractures Geological Socicty of MANN P HEMPTON M BRADLEY D c AND BURKE 1983 America Bullctin v 81 p 41 60 R K Develupment of pull apart basins Juurnal uf Gcology v 91 p 529 VAN HINTE J E 1978 Geohistury analysis application uf micropa 554 leontology in cxploration geology American Association of Petroleum MCCLAY K R 1981 What is a thrust What is a nappe ill McClay Geologists Bulletin v 62 p 201 222 KR and Price N J cds Thrust and Nappe Tectonics Geological WALKER R G 1984 General introduction Facies facies sequcnces and of London Publication No 9 7 9 facies models i1 Walker R G Facies Models Geusciencc Can Society Special p ed MEANS W D 1976 Stress and Strain New York Springer Vcrlag ada Reprint Scrics I 2nd edition p 1 9 Marine Tech 339 p WATTS A B 1983 The strength of the Earth s crust MITCHUM R M JR 1977 Seismic stratigraphy and global changes of nology Society Journal v 17 p 5 17 Part II of terms used in seismic ill WATTS A AND RYAN W BF 1976 Flexure of the Glossary slratigraphy B lithosphere 386 KEVIN T BIDDLE AND NICHOLAS CHRISTIE BLICK

1928 Dead Sea rift or and continental margin basins Tectonophysics v 36 p 25 44 WilLIS Bailey problem valley ramp valley of America Bulletin v 39 p 490 542 WfIITE DA 1980 Assessing oil and gas plays in facies cycle wedges Geological Society J T 1965 A class of faults and their on conti American Association of Petroleum Geologists Bulletin v 64 p 1158 WilSON new bearing nental drift Nature 207 343 347 1178 v p WilCOX R E HARDING T P AND SEELY D R 1973 Basic wrench tectonics American Association of Petroleum Geologists Bulletin v 57 p 74 96