The fossil record of shell boring by snails
Norman F. Sohl
1969, American Zoologist (9) 725-734
The predatory boring habit common to many recent snails probably arose first in the Polinicinae (Naticacea) during Upper Cretaceous (Cenomanian) times (100 million years B.P.) . In the fossil record the frequency of bored shells increases greatly in rocks of latest Cretaceous age and becomes more widespread during early...
A geophysical study of North Park and the surrounding ranges, Colorado
John Charles Behrendt, Peter Popenoe, Robert E. Mattick
1969, Geological Society of America Bulletin (80) 1523-1537
A geophysical study in the North Park basin and surrounding mountains, Colorado illustrates the structural relationship of various sedimentary, metamorphic, and igneous rock units. Bouguer anomalies from 1330 gravity stations range from −210 mgal over Precambrian metamorphic rocks in the mountains to −260 mgal in the Walden syncline and —280...
Temporal variation of alkaline earth element/chlorinity ratios in the sargasso sea
G.K. Billings, Owen P. Bricker III, F.T. MacKenzie, A.L. Brooks
1969, Earth and Planetary Science Letters (6) 231-236
An open ocean hydrographic station located 14 miles SE of the Bermuda Islands was sampled at two week intervals through a vertical profile of 2600 meters and over the period June 1966 to March 1967. 428 samples were analyzed for Ca, Mg, Sr...
Inflation of Kilauea Volcano prior to its 1967-1968 eruption: Vertical and horizontal deformation give clues regarding the structure of an active Hawaiian volcano
Richard S. Fiske, Willie Tomoni Kinoshita
1969, Science (165) 341-349
No abstract available....
Fault-plane Solution of the Koyna (India) Earthquake
W.H.K. Lee (compiler), C.B. Raleigh
1969, Nature (223) 172-173
THE peninsular shield of India has long been regarded as a stable region. The area had not been subject to orogenic deformation since the Pre-Cambrian, although a vast area (5 × 105 square km) was flooded by basalts during Late Cretaceous to the Eocene—the Deccan Trap. Several...
Distribution of scandium between coexisting biotite and hornblende in igneous rocks
Robert I. Tilling, L. Paul Greenland, D. Gottfried
1969, GSA Bulletin (80) 651-668
Scandium analyses of more than 90 pairs of coexisting biotite and hornblende from igneous rocks of various provinces (including Southern California, Boulder, Sierra Nevada, Boulder Creek batholiths and the Jemez Mountains volcanic rocks) indicate that the distribution ratio (Kd = Schornblende/Scbiotite) for most samples closely approached that of an equilibrium distribution....
Alkalic and tholeiitic basaltic volcanism related to the Rio Grande depression, southern Colorado and northern New Mexico
Peter W. Lipman
1969, Geological Society of America Bulletin (80) 1343-1353
Upper Cenozoic basaltic rocks in and near the northern Rio Grande depression, a major intracontinental tension-rift structure, vary systematically in petrology and chemistry with distance from the depression. Basalts and basaltic andesites of alkalic affinities, commonly showing evidence of crustal contamination, were erupted east and west of the depression concurrently...
Confidence limits for the precision parameter κ
Allan Cox
1969, Geophysical Journal International (17) 545-549
Confidence limits are calculated for the precision parameter κ used in the analysis of palaeomagnetic data and for the angular standard deviation σ. A set of tables for 95 per cent and 99 per cent confidence limits is presented....
Principal stress directions from plastic flow in crystals
Neville L. Carter, C. Barry Raleigh
1969, Geological Society of America Bulletin (80) 1231-1264
Methods for determining orientations of principal stress axes in deformed rocks involve dynamic analysis of twin-gliding and of extinction bands produced by inhomogeneous translation gliding in crystals. The methods, beginning with Turner's (1953) technique for dynamic analysis of calcite twins, have been developed using as...
Carbon isotopes in pelites of the Precambrian Uncompahgre Formation, Needle Mountains, Colorado
Fred Barker, Irving Friedman
1969, Geological Society of America Bulletin (80) 1403-1407
Carbon isotopic ratios and weight percentages of carbon were measured in 15 samples of slate, phyllite, and schist of the approximately 1500- to 1600-m.y.-old Uncompahgre Formation of the Needle Mountains, southwestern Colorado. Rocks with less than 1 percent total carbon, all of which is reduced, have δC13 values of −23 to...
Errors in using modern stream-load data to estimate natural rates of denudation
Robert H. Meade
1969, Geological Society of America Bulletin (80) 1265-1274
The practice of calculating natural rates of denudation from routinely collected data on the loads of suspended and dissolved matter in modern rivers is subject to several significant errors. The sources of these errors are demonstrated by examples from the Atlantic drainage of the United States, where their total effect...
Measuring underground-explosion effects on water levels in surrounding aquifers
M. S. Garber, Leonard E. Wollitz
1969, Groundwater (7) 3-7
Underground detonations may produce observable effects in surrounding aquifers and wells. The nature and the duration of the effect at any observation point seem to depend on several factors such as the amount of energy released by the detonation, the geologic environment, the position of the buried explosive device in...
Field use of orifice meters
Donald G. Jorgensen
1969, Groundwater (7) 8-11
A well-designed and calibrated orifice meter is an accurate and inexpensive measuring device for flow. Endline orifices can be calibrated at work sites by solving an equation that interrelates easily measured dimensions of the orifice and outflow....
Ultramafic and basaltic rocks dredged from the nearshore flank of the Tonga Trench
Robert N. Fisher, Celeste G. Engel
1969, Geological Society of America Bulletin (80) 1373-1378
Deep dredging in the Tonga Trench (Southwest Pacific Ocean) at a depth of 9150 to 9400 m yielded fresh to granulated and serpentinized peridotite and dunite. Other rocks recovered there and at three stations deeper than 7000 m include basalts, tuffs, and tuffaceous agglomerates.Chemical analyses of the fresh peridotite, with...
Age and chemistry of mesozoic and tertiary plutonic rocks in south-central Alaska
Bruce L. Reed, Marvin A. Lanphere
1969, GSA Bulletin (80) 23-44
On the basis of potassium-argon mineral ages, plutonic rocks in an area of approximately 22,000 square miles in the southern Alaska Range and the Aleutian Range can be assigned to age groups that show differences in chemical characteristics and geographic distribution. The plutonic groups are Early and Middle Jurassic, Late...
Hydrology of carbonate rock terranes — A review: With special reference to the United States
V.T. Stringfield, H. E. LeGrand
1969, Journal of Hydrology (8) 349-376
Limestone and other carbonate rocks are characterized by many unusual features and extreme conditions, either involving the hydrologic system within them or wrought by hydrologic conditions on them or through them. Perhaps there could be little agreement as to what is typical or average for the many features of carbonate...
Theoretical basis of the borehole deepening method of absolute stress measurement
Rodolfo V. de la Cruz, Richard E. Goodman
1969, Conference Paper, The 11th U.S. symposium on rock mechanics
Knowledge of the initial state of stress in rocks provides a key to the solution of many problems in rock mechanics. The initial state of stress is part of the basic data required for rational design of structures in rock, since its redistribution when engineering activities are conducted is a...
Duck viral enteritis (duck plague) in North American Waterfowl
Louis N. Locke, Louis Leibovitz, Carlton M. Herman, John F. Walker
James W. Webb, editor(s)
1969, Conference Paper, Proceedings of the twenty-second annual conference of the Southeastern Association of Game and Fish Commissioners
Duck Viral Enteritis (DVE) was first recognized in North America in January 1967, when an outbreak occurred in a commercial flock of white Pekin ducks in Suffolk County, Long Island, New York (Leibovitz and Hwang, 1968b). Originally described as a disease of domestic ducks in the Netherlands, DVE has since...
Model for simulation of residual stress in rock
D. J. Varnes
1969, Conference Paper, Proceedings of the 11th U.S. Symposium on Rock Mechanics (USRMS)
Rocks in mines, quarries, and many outcrops commonly show evidence of being under high stress. Saw cuts and drillholes close in, partly mined coal bursts violently, and pillars crush and rock spalls in mines even at moderate depths. Similarly, strong and massive rocks such as granite and sandstone naturally divide...
Isotopic composition of lead in volcanic rocks from central Honshu — with regard to basalt genesis
Mitsunobu Tatsumoto, Roy J. Knight
1969, Geochemical Journal (3) 53-86
The isotopic composition of lead and concentrations of lead, uranium, and thorium were determined in tholeiitic and high-alumina basalts, and their calc-alkali rock series, from central Japan. The isotopic composition of lead of high alumina basalts is similar to that of tholeiites from adjacent areas, whereas their silicic differentiates (calc-alkali...
Nuées Ardentes of the 1968 Eruption of Mayon Volcano, Philippines
James G. Moore, W.G. Melson
1969, Bulletin Volcanologique (33) 600-620
Mayon Volcano, southeastern Luzon, began a series of explosive eruptions at 0900 April 21, 1968, and by May 15 more than 100 explosions had occurred, at least 6 people had been killed, and roughly 100 square km had been covered by more than 5 cm of airfall ash, blocky ash...
Seismic-refraction measurements in Jackson Hole, Wyoming
B. L. Tibbetts, J. C. Behrendt, John David Love
1969, Geological Society of America Bulletin (80) 1109-1121
Three reversed seismic-refraction profiles were recorded in the Jackson Hole, Wyoming, area during July 1964. The seismic model which was developed consists of three layers with velocities of 2.4 km/sec for Tertiary and Cretaceous rocks above the Cleverly Formation (Lower Cretaceous), 3.8 km/sec for rocks from Lower Cretaceous down to...
Water, population pressure, and ancient Indian migrations
D. O'Bryan, M. E. Cooley (compiler), T. C. Winter
1969, Eos, Transactions, American Geophysical Union (50) 438-442
A preliminary report on environmental factors relating to some prehistoric Indian migrations in the lower San Juan Valley region, northeastern Arizona...
Role of cohesive strength in the mechanics of overthrust faulting and of landsliding: Discussion
M. King Hubbert, William Walden Rubey
1969, Geological Society of America Bulletin (80) 953-954
No abstract available....
Physical and chemical factors in the formation of marine apatite
R. A. Gulbrandsen
1969, Economic Geology (64) 365-382
No abstract available....
