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ey。 It may therefore be accepted as a fairly accurate and authoritative presentation of the geological conditions existent at the Canyon； with their explanations； as accepted by the leading scientists of to…day。
The beginning of land。 In the long ago centuries； when the world was 〃without form and void；〃 waters covered the face of the earth； and darkness brooded over the waters。 As the earth's crust began to shrink under the water； in the process of cooling； the first masses to crumple up； to wrinkle； were the first to arise above the surface of the vast； primeval； shoreless ocean。 They appeared as tiny islands； pinnacles； or ridges thrust up； exactly as we see them sometimes on the coast；hidden at high tide； appearing again at low tide。
The Laurentian Hills。 Nature had plenty of time before her； so she did not hurry her work； and it took long centuries before there was any large amount of land thrust up out of the bosom of the sea。 The scientists are able to tell us； with some definiteness； which came forth first。 They say that on the continent of America the earliest born land was a mass of granitic rock in Canada；the Laurentian Hills。 The next to peer above the surface and feel the warmth of the sun were peaks and ridges that made islands of themselves； in what are now known as the Rocky Mountains and the Appalachians。 Now； at last； the great waves of the sea and the resistless storms had something to play with； and they pounced down upon the land as with tooth and claw。 They rubbed and pounded； raged and smashed for a thousand years； and then another thousand； and still another； while Mother Earth uneasily thrust forth her rocky children out of the ocean into the light of day。 Surprised at such treatment by the storms and seas； the newly born earth masses began to crumble and 〃weather。〃 The detached fragments slipped back； or were washed back； into the deeper or shallower parts of the ocean； and were there tossed back and forth； pounded and ground into sand and silt； into pebbles and boulders； while more land was slowly being thrust out for the angry sea to work upon。 Layer by layer； the ground…up masses were deposited in the inner ocean bed； parts of which were now practically shut off from the vast ocean beyond。 How many centuries of centuries this process continued geologists do not tell us。 Time is so vast； so long； that they cannot divide those early days into weeks； months and years； as we now do。
The Continent is born。 After many millions of tons had been thus ground up and tossed about and mingled with the waters of the seas； the earth； in a fit of fiery anger； turned and baked them； with intense heat； out of all semblance to their former appearance。 These baked masses； in the course of time； were thrust up out of the seas； mashed and macerated once more； again deposited as sand； silt； pebbles and boulders； and again burned。 These processes followed each other； how many times we do not know； the earth all the while keeping up her steady uplift of the children of her bosom out of the great sea。 Higher and higher came the land。 Further and further receded the sea； until； in due course； the sun shone upon a vast area of land that was the rude skeleton of what is now the continent of North America。
It would have taken a keen eye； however； to have imagined from that which we see to…day what was there。 The Gulf of California reached far up； even into Nevada； and covered what are now the Mohave and Colorado Deserts； there was no California Coast Range； the Gulf of Mexico was vastly larger than it is to…day； covering all Florida； and reaching up the Mississippi Valley half…way to the Great Lakes。
The First Strata。 It was just preceding the last uplift of this epoch that the era of deposition of rock debris was so prolonged that twelve thousand feet of strata were washed into the bed of the sea； in the region now known as the Grand Canyon Country。 It was at the time when life was beginning to dawn； for in the remnants of the strata are found fossils of the earliest known life。 These strata； therefore； are of immense interest to the geologist； as they are the first known rocks containing life to emerge from the primeval sea。 Within the last few years； they have been called the Algonkian Series； and later I shall speak of them more freely。
Prior to the deposition of these Algonkian strata； the Laurentian rocks （the granite） upon which they rest were subject to a long period of 〃planation；〃as the grinding down and leveling of rock surfaces is termed。 After this planation was complete； a subsidence occurred； the whole area became the bed of an inland sea； and upon the planed…down granite； the debris that formed the Algonkian strata was washed。
While they were being deposited； the whole region was the scene of several seismic and volcanic disturbances； for great dykes and 〃chimneys〃 of lava are found； showing clearly that； by some means or other； the strata were broken and shattered； cracked and seamed； and that through these cracks the molten lava oozedforced up from the interior of the earth。 It spread out over the Algonkian rocks in small sheets or blankets； which here and there are still to be found to…day。
Tilting of the Algonkian Strata。 Slowly this twelve thousand feet of strata emerged into the sunlight。 In the uplifting processes； the surface of the earth； where they were； became tilted； and these strata therefore 〃dipped〃 or 〃tilted〃 away from the perpendicular。 As they emerged； weathering and erosion began。 It is most probable that this process of degradation began and continued while the topmost strata were at or near sea level； so that it was a simultaneous process with the uplift。
Erosion of the Algonkian。 How many centuries this weathering and washing away process consumed no one knows。 At the close of this epoch； however； the Algonkian strata had been eroded almost away； owing to its tilted condition； so that in some places even the surface of the Archaean was exposed； and suffered the planing…down process。 Figure 1 on plate facing page 98 is a suggestion as to the possible appearance of the rocks at this time。
Even then； in those far…away； early ages of history； if one had been present to measure these strata； he would have discovered the astounding fact that； although he had measured them and found twelve thousand feet before they began to emerge from the ocean； there were but about five hundred feet of them left。 This is one of the interesting facts in geology；that an observant reader can deduce so much from so little。
The twelve thousand feet deposit。 〃But；〃 asks the layman； 〃I cannot possibly see how； if only five hundred feet of strata are left； any one could ever tell that there were once twelve thousand feet。 If eleven thousand five hundred feet are gone； how do you know they ever existed？〃
A very reasonable question and one very easily answered。 Refer to the sketch。 Let the bracket on the right show the present width of the remaining strata； viz： five hundred feet。 Now observe the tilted condition of the remnants。 To get the original height of the depositions begin with No。 1； the stratum nearest the Archaean and measure that。 Suppose it gives us five hundred feet。 No。 2 gives two hundred feet； No。 3； five hundred feet； No。 4； one hundred and seventy…five； and so on up to No。 14。 As these strata were deposited horizontally； all we have to do is to mentally replace them in their horizontal position。 Throw the tilted strata back again into their original condition； and by this method of measurement it is seen that the twelve thousand feet can be made up。 Figure 2； facing page 98。
Another interesting question here arises： 〃What became of the vast quantity of sand and silt and pebbles that formed and were carried away during such a gigantic process？ For； think of it； eleven thousand five hundred feet of strata； or rock； two miles high； almost three times as high a mass as the present distance in vertical height from El Tovar to the river！ Where has it all gone？〃
Naturally an answer to these questions is mere conjecture； as only from a study of the facts revealed underneath the present strata； can any comparative knowledge be gained of the conditions existent at that prehis