Several preconditions must be satisfied before a Rb-Sr date can be considered as representing the time of emplacement or formation of a rock.

The resulting Rb-Sr ratios and Rb and Sr abundances of both the whole rocks and their component minerals will be markedly different.

A Rb-Sr date which is at variance with other geochronometers may not be useless, it may be providing data on an event which is not representing the age of formation of the rock.

The Rb-Sr dating method has been used extensively in dating rocks.

Rb-Sr dating relies on correctly measuring the Rb-Sr ratio of a mineral or whole rock sample, plus deriving an accurate < sup > 87 </ sup > Sr /< sup > 86 </ sup > Sr ratio for the mineral or whole rock sample.

A radiometric age for the Cretaceous-Tertiary boundary based on K-Ar, Rb-Sr, and U-Pb ages of bentonites from Alberta, Saskatchewan, and Montana.

# Foliated charnockite from Filchnerfjella, part of the Orvin Mountains in central Dronning Maud Land, east Antarctica, yielded a Rb-Sr whole-rock isochron age of 536 ± 56 Ma, a new date which constrains the major tectonothermal event ( D2 ) in the area.

The impact was first dated ( at 243 ± 19 million years ago, with Rb-Sr method ) by Deutsch et al.

* The rock must not have undergone any metasomatism which could have disturbed the Rb-Sr system either thermally or chemically

These dates were established by a variety of radiometric dating techniques, including samarium-neodymium ( Sm-Nd ), rubidium-strontium ( Rb-Sr ), potassium-argon ( K-Ar ), and carbon-14.

" Macrocrystal phlogopite Rb-Sr dates for the Ekati property kimberlites, Slave Province, Canada: evidence for multiple intrusive episodes in the Paleocene and Eocene ", 8th International Kimberlite Conference Selected Papers, vol.

Curly hair, high cheekbones, wide gnomelike mouth, a pair of drummer's blocky hands, and a body that said well, maybe I can wrestle you for ten minutes -- but then I'm finished.

It is well then that in this hour both of `` national peril '' and of `` national opportunity '' we can take counsel with the men who made the nation.

If man is actually the product of his environment and if science can discover the laws of human nature and the ways in which environment determines what people do, then someone -- a someone probably standing outside traditional systems of values -- can turn around and develop completely efficient means for controlling people.

Where, then, can we look for improvement??

What can a mother do then to prevent misbehavior??

If it will simply delay the debates until the qualifications are closed next spring, and then carry all the candidates on a tour of debates, it can provide a service to the state.

As this tax base grows so then can your medium and low density residential areas grow.

Whether the compromises -- on both sides -- that made possible the interim appointment can then be repeated remains to be seen.

`` Unless the oyabun has been working on it '', he said, then checked himself and added: `` You can tell Kayabashi-san that the back road is in very good condition and will be quite safe for his party to use ''.

What type of action can hope to win public support, first in this country and then abroad??

It can then grow steadily as it proves itself and as the need for it is demonstrated.

During nighttime hours, because of the intense skywave propagation then prevailing, no large number of stations can be permitted to operate on one of these channels, if the wide area service for which these frequencies are assigned is to be rendered satisfactorily by the dominant stations which must be relied upon to render it.

Here then is our problem: aircraft are vital to winning a war today because they can perform those missions which a missile is totally incapable of performing ; ;

Multiplication, subtraction, and addition can then be accomplished as they appear in the equation by starting at the left end of the equation and working toward the right.

You can save all that shimming time if you set your windows in one, two, three order -- first the stud on one side, then the window, then the stud on the other side.

For those who need or want and can afford another car, buying one and driving it on the grand tour, then shipping it home, is one popular plan for a do-it-yourself pilgrimage.

If the vertex is at Af, and if the interior of C is on the left as one moves in the direction of increasing t, then every such corner can be found from the curve obtained by rotating C clockwise through 90-degrees about the vertex.

Thus if E is sufficiently small, there can be only one intersection of C and Af near Q, for if there were more than one intersection for every E then the difference between C and Af near Q would not be a monotone function.

Now the only way in which all curves of the image family of Af can pass through a fixed point is to have a generator of Af which is not a secant but a tangent of **zg, for then any point on such a generator will be transformed into the point of tangency.

But if no two lines of the regulus of multiple secants of **zg can intersect, then the regulus must be quadratic, or in other words, **zg must be either a Af or a Af curve on a nonsingular quadric surface.

In the written language then can be underlined or italicized to guide the reader here, but much of the time the written language simply depends on the reader's alertness, and a careless reader will have to back up and reread.

and these costs must somehow be apportioned among the various classes and then must somehow be reapportioned among the units of service in order to report unit costs that can serve as tentative measures of reasonable rates.

If the patient can perceive figure kinesthetically when he cannot perceive it visually, then, it would seem, the sense of touch has immediate contact with the spatial aspects of things in independence of visual representations, at least in regard to two dimensions, and, as we shall see, even this much spatial awareness on the part of unaided touch is denied by the authors.

`` That is, if we can be sure this is Colcord's money '' --

It'll probably be at least an hour or two before I can check back with you.

Even as I said it I realized that an education can be invaluable.

Within their confines, moreover, technological and industrial growth has proceeded at an accelerated pace, thus increasing the cornucopia from which material wants can be satisfied.

And no messages can be transmitted on these circuits until senders and receivers authenticate in advance, by special codes, that the messages actually come from their purported sources.

Additional codes can be used to challenge and counterchallenge the authentications.

Nobody can be absolutely certain of the answers.

All can be connected with the gold circuit from their homes.

The box is internally wired so the door can never be opened without setting off a screeching klaxon ( `` It's real obnoxious '' ).

Unless all gadgets are properly operated -- and the wires and seals from the handles removed first -- no damage can be done.

I do not know if such a way of life can come to be a self-conscious challenge, but I suspect that it can.

As his disciples boast, even though his emphasis is elsewhere, Faulkner does show his awareness of the changing order of the South quite keenly, as can be proven by a quick recalling of his Sartoris and Snopes families.

An order can be chanced rather than chosen, and this approach produces an experience that is `` free and discovered rather than bound and remembered ''.

And any sequence can not only change its positions in the work but can even be eliminated from it altogether.

When it comes to this, I shall prefer emigrating to some country where they make no pretence of loving liberty -- to Russia, for instance, where despotism can be taken pure, without the base alloy of hypocrisy '' ( His emphasis )

Something of this can be learned from `` The Way To The Churchyard '' ( 1901 ), an anecdote about an old failure whose fit of anger at a passing cyclist causes him to die of a stroke or seizure.

Similarly experience itself can be conventionalized so that people react to certain preconceived clues for behavior without awareness of the vitality of their experiential field.

When words can be used in a more fresh and primitive way so that they strike with the force of sights and sounds, when tones of sound and colors of paint and the carven shape all strike the sensibilities with an undeniable force of data in and of themselves, compelling the observer into an attitude of attention, all this imitates the way experience itself in its deepest character strikes upon the door of consciousness and clamors for entrance.

it can be changed ; ;

You've already sent your daughter to Miss X's select academy for girls and your son to Mr. Y's select academy for boys, and you can be as liberal as you please with strict impunity.

In scope and power it can only be compared to Tolstoy's War And Peace.

However, for convenience we will stick to the idea that information can be classified according to Table 1.

Since the hazards of poor communication are so great, p can be justified as a habitable site only on the basis of unusual productivity such as is made available by a waterfall for milling purposes, a mine, or a sugar maple camp.