23A

sions on t h e implications of t h e work for seismic probing a h e a d a t u l t r a s o n i c f r e q u e n - c i e s add on ultrasonic evaluation of rock quality in a tu~m6 context.

Geology

772058 CGRRELR~ION ~ LENGTH AND OFFSET IN STRIEE- SLIP FAULTS Radii, G Tectonophysics, V37, ~, 2 Feb I977,~TI-T7

Strike-sllp faults in continental crust are shown to exhibit non-lineer positive correla- tion between length add offset. This cO~rela - tion can be empirically explained as the co,- bided effect of the changes in the growth rates of offset amd length durimg the time of tectonic activity of a fault.

772059 MATHEMATICAL MCDEL FOR 0RIERTATION DATA FRCM MACROSCOPIC CYLINDRICAL FOLDS Kelker s D; Lamgenberg, C W J Int Ass Math Geol, V8, NS, Oct 1976,

~549-559

Discusses the use of Bir~am's distribution for amalyzir~ orientation data from a cylin- drically folded surface. Parameters of the distribution give information on the spatial attitude, shape amd symne t~y of the fold, b u t n o t o n t h e s i z e o r t i g h t n e s s o f t h e f o l d . Wi th a probability distribution fitted to the fold it is possible to test hypotheses such as whe- ther two folds, or two segments of the same fold, have the same fold axis.

772060 GEOLOGICAL IMPLICATIONS OF SI~EADY ST~E MECH- ANISMS IN CATASTROPHE THEORY

Cubitt, J M; Shaw, B J Int Ass Math Gecl, V8, N6, Dec 1976, P657- 662

Gives a brief introduction to catastrophe theory and outlines the problem of equilibri~n as it relates to geological application of the theory. Illustrates a proposed solution to this by a model for sediment transport on t he continental slope •

772061 CATASI~OPHE THEORY MODELS IN GEOLOGY Henley, S J Int Ass Math Geol, VS, N6, Dec 1976, P649-

6~5

Catastrophe theory is a recently developed branch of topology which has a nt~nber of prac- tical applications, principally because of its ability to model situations which include dis- continuities cr slDgularitles, where the methods of differential calculus break down. Outlines of how the theory may be applied to volcanic ash and nuees ardentes, turbiditles add fault movement ere given.

"r72~2 SHEAR ZONES INSIDE GULF COAST SALT STOCKS HELP TO DELINEATE SPINES OF MOVEMENT

Ku~fer, D H Am Ass Petrol Geol Bull, V60, ~, Sept 1976,

n434-1~7

In the course of mapping salt structures in the salt mines of Louisiana add elsewhere, evidence has been four~ to confirm the idea that discrete masses of salt called s~Ines,

move indepemdently and with different velocities, ereatir~ a zone of shearing movement. The eml~hasis of this paper is on the character of the evidence, its implications tO salt-dome geology, and how spines might affect the sur- rounding sedimentary rocks.

772063

Tectonic process

FOLD DEVELOPMEN~ IN THE JURA Laubscher, H P Tectonophysics, V37, N4, 2 Feb 1977, P337-

362

Describes the general situation at the onset of foldir6, based on mapping anl stratigraphic analysis, in terms of tectonostatics. The dis- cussion is in terms of cross sections with occasional outlooks into the third dimension, and the scale is restricted to lO-lO00m.

Earthquake mechanisms and effects

772~ LONG AND SHORT THeM EARTHQUAKE PREDICTION IN KAMCHATKA

Fedotov, S A; Sobolev, S A; Boldyrev, A A Tectonophysics, V37, E%, 2 Feb 1977, I>305-

321

Presents the results of long-areal sheet-term earthquake prediction obtained durir~ 1971- 1974.

772065 TIME-D(IWAIN DETONATION OF EARTHQUAKE FAULT PARAME~S FR(~ SHCRT PERIOD P-WAVES

Somerville, P G; Wi~ins, R A; Ellis, R M Bull Seismol Soc Am, V66, ~, Oct 1976, P1459-

1484

772066

Source parameters of two shallow earthquakes have been determined by the time-domaln armly- sis of short-period teleseismic reccm~lirgs, the objective being to investigate whether a shear dislocation model of earthquake rupture can describe the teleseimuically recorded short-period radiation of earthquakes having SmS11 sot~ce dimensions.

EARTHQUAKE PREDICTION AND ROC~ ~CHANICS. CON- TRIBL~ION TO CURREET RE~a/~CH IN GEOPHYSICS Wys,, M (editor) Basle: Birkhauser Verlag, 1975 , 330P

A collection of 28 papers on the behaviour of rocks under load in lab test conditions, on field observations of precursors of tectonic shocks and on theories amd models of earthquake precursory phenomena, reprinted from Pure and Applied Geophysics, Vol 113, 1975.

Underground Excavations

772067 LANCA~A'~ DEBUT FOR ROCK BORING RIG Ground Emgng, VlO,NI, Jan 1977, PS9-40

Briefly describes Pigctt Foundations Lid new bedim6 rig which is capable of drillimg in a single pass holes up to 8ft in diameter or to