Post by 1dave on Mar 21, 2020 17:08:32 GMT -5
It happened around 1860 in Europe.
Rhyolite is similar in composition and appearance to granite, but it is extrusive instead of intrusive - that is, it forms above ground instead of under it.
The word rhyolite comes from the German Rhyolith, derived by from Greek rhyax stream, stream of lava (from rhein) + German -lith -lite given to rocks by Baron Ferdinand Freiherr von Richthofen 5 May 1833 – 6 October 1905) Uncle to the Red Baron of WWI fame.
From 1862 to 1868, he worked as a geologist in the United States, discovering goldfields in California.
Between 1866-67 he wrote a book that solidified the new word in Geology Annals.
It was a hard book to find - and even then at the back of another book about moss.
books.googleusercontent.com/books/content?req=AKW5QafUSiI2A5N3cwoFO6xJS_hCYguiHwWEdR3dd5p0VNZNypT67Wl1D4Y2BfEdvW_HKzbDUZV_8HOLx1K1nw8T_ISPPiEPV83jZtHOotrQI1I1smXKgPKGGBIkkQ5mP-ZkjMrAyFThcPzIhvU7c7UoxYcV6cr_1WgWVWsrIJAqZ5_-zbp4QR88-2BkUWGUc8nqnS4ap4imBsLdLLTsU1ZXOsr43u7qeGR2XcyGRZ0TEy8QboUaSCJEDxsdEdZc-S7LhXQIg9brEuWiFHCytKI-ZNHWKOieNA
Here are the parts I particularly enjoyed:
PRESENTED TO THE CALIFORNIA ACADEMY OF SCIENCES.
By German geologist Baron Ferdinand von Richthofen, Dr. Phil. [Presented, May 6th, 1867.]
TABLE OF CONTENTS.
. . . . . PAGE.
Introductory 1
The Natural System of Volcanic Rocks 5
Order First : Rhyolite 12
Order Second : Trachyte 17
Order Third : Propylite 20
Order Fourth : Andesite 25
Order Fifth : Basalt 26
Correlation of the Five Orders of Volcanic Rocks 28
Laws Relative to the Age of Massive Eruptions 29
Laws regarding the Mutual Relations of Massive Eruptions and Volcanic Activity 32
Relation of Volcanic Rocks to Ancient Eruptive Rocks 35
Correlation of Age and Texture 39
Correlation of Age and Composition 41
Correlation of Eruptive Rocks in regard to their Geographical Distribution 43
On the Origin of Volcanic Rocks 46
1. Origin of Massive Eruptions 47
2. Origin of Volcanic Action 60
3. Other Theories regarding the Origin of Vocalic Rocks 68
Relation of the Distribution of Volcanic Rocks to the Configuration of the Surface of the Globe 78
INTRODUCTORY.
Among the features peculiar to modern Geology may be noticed a revival of that speculative tendency which prevailed among the cultivators of this science at the close of the last century. But while in those early times imagination exerted a dominant influence in the framing of hypotheses, and discussions between the adherents of different doctrines were conducted with all the bitterness peculiar to such struggles, when neither party has a firm basis upon which to found its arguments, the constant ascendency of the spirit of the inductive method has imparted to those theories more recently propounded a more logical and scientific form, while, at the same time, the increasing amount of positive knowledge has given to the different doctrines a more varied and more definite character, and enlarged the scope of dissenting views.
############
A number of theories have been proposed, in rapid succession, relating to the origin of rocks, to the mode and causes of metamorphism, to the agencies of vulcanism, to the structure and mode of formation of mountain ranges, to the structure of the entire globe, and other cognate subjects.
It will be admitted, even by those who are most strongly opposed to theorizing, that geological science has in this way been promoted and enriched in various respects ; since there is scarcely a theory which, even if insufficient to explain what it under takes, has not some truth in it, or is applicable to some extent in certain cases, or has at least, even when proving to be erroneous itself, led to discussions on subjects of high interest, which is indeed a result of no little value. In reviewing the theories proposed on any particular subject, we find them, it is true, often in apparent contradiction with each other ; yet almost every one is based upon arguments drawn from observed facts, and there are probably very few which will ultimately be entirely abandoned. The immense range of varied processes as applied by nature allows the applicability, in a limited way, of many a theory in certain instances, while in others it may be refuted on no less valid grounds ; and the struggle between the defenders of different doctrines is often founded only in the difference of their standing-points.
What appears to be true in one instance is frequently not applicable in others ; it is the bold generalizations which render theories so often untenable in that form in which they are usually first expressed. An instructive example is presented by the different theories which have been proposed for explaining the mode of formation of mineral veins. Almost every one of them was based upon a limited range of observations, and was, from its first application to a few instances, extended to the generality of veins.
Numerous exceptions to it were then found, leading to the rejection of the first, and the establishment of a different, theory, Which, in its turn, shared a similar fate. Obscure as this subject still is, we are able to state this as certain, with our present state of knowledge, that every mineral vein is the product, not of one simple but of complex processes. Nearly every one of the theories proposed will, therefore, have its limited range of applicability, inasmuch as the agent it suggests may have 'been especially active in the formation of the veins of a certain order, while the same agent may have played a subordinate part in regard to the origin of other veins which were chiefly due to processes of another kind.
This instance points clearly towards the one principal cause of the divergence of opinions in regard to some of the most important geological questions. This cause is the want of latitude of the basis upon which arguments are founded. Conclusions which are obtained by reasoning on geological subjects solely on the strength of chemical analysis, are, when generalized, often found to be utterly in discordance with the
(40) INTRODUCTORY. 6
facts revealed by geological observation ; and how unsatisfactory general theories may be when based upon the latter alone, is sufficiently exemplified by the fantastical attempts made in all ages of geological science to interpret the geological structure of the world from that of a limited region. The basis for argumentation can therefore never be broad enough, and its enlargement should be, as it indeed is, one of the chief objects of geological science. But it is not sufficient to content ourselves with an accumulation of primary observations, which are in fact being infinitely increased by the conjoint labors of geologists in all countries : it should be a higher object of the student of geology, to compare the established results of observation, and to investigate their mutual relations. The study of the structure of one mountain range, or of several ranges comprised within a limited district, may lead to the establishment of an elaborate theory of the mode of their formation, which may apparently answer perfectly well in that one case, but may be found inadmissible when generalized, even in those cases where, by imperfect observation, one would expect to detect a great similarity to the structure first observed. But in determining those features which are common to a number of mountain ranges, or to certain orders of them which we may discern among their generality, we may aspire to form conclusions which are more generally applicable. It is particularly the auxiliary branches of geology to which these remarks apply. The value of observations made in limited regions, or from a limited point of view, on subjects such as the outlines of the morphological .feat ures of the continents, the occurrence of mineral springs, the structure of mineral veins, the age of those among them which carry a certain metal, the generality of volcanic phenomena, the mode of action of earthquakes, the nature of certain kinds of rocks, and their part in the structure of the surface of the globe—cannot be fully realized unless the comparative method is applied in as wide a scope as we may be able to do, and the mutual relations among the different modes of manifestation of force, or among the properties of the kinds of matter upon which it acts, or the bearing of all these relations to each other and to the evolution of the globe, are investigated from as many points of view as we may detect, and in as many combinations as possible.
We may then be able to gain a foundation for argumentation on more involved problems, consisting not of imperfect premises, nor of a confused accumulation of facts, but of established truths of a higher order.
##############
The mode of origin of the non-foliated crystalline rocks, made up of silicates,* is among those subjects which have at all times, but at no time more than of late, commanded a great deal of attention, and given rise to the establishment of numerous theories, each of which was applied in a general way, if not by its author, then by his followers. It is well known how conflicting they apparently are, and what weighty arguments have been brought in favor of as well as against each of them. The only method, promising success, of weighing the merits of these different theories, or of modifying them in accordance with the general advance of science, appears to be, to
* I have J"or these applied the Dame " eruptive rocks " in the following pages, considering that, wherever we have
occasion to observe them, they are not at their original seat, but ejected from it towards the surface. The reasons supporting
this position will be more fully mentioned in the chapter on the origin of volcanic rocks.
ascend from the examination of the nature of these rocks to that of their mutual relations, to investigate these from as many points of view as we can discover, in regard to physical and chemical properties, mode of occurrence and age, as well as in regard to geographical distribution : that is, to try to establish the natural system of eruptive rocks. The results so obtained may then, in accordance with what we just remarked in a general way, be applicable to reasoning on remoter questions, of which we can only attempt to find the most probable solution. They regard chiefly the causes of those relations, the mode of origin of the eruptive rocks, and the processes connected with their ejection. The intricate nature of the subject, and the fact that the present changes on and below the face of the globe, as well as the events of the past, are often but dimly and imperfectly perceptible to our observation, demand that we should concentrate our endeavors in exploring first the laws of that which is definite and constant within the infinite range of phenomena, and await further experience to arrive at an explanation of those isolated facts which form apparent exceptions to the order of things.
It is with these views that the following pages were written. They extend chiefly over the comparatively limited, and yet very extensive class of "volcanic rocks," and are offered as a mere elementary attempt, which is necessarily very imperfect.
The application to exact reasoning of the numerous observations which have been made on the subject of volcanic rocks in different countries, is nearly prevented by the extraordinary discrepancy existing in regard to the mode in which the names of rocks are used by different authors. The first condition of a uniform and harmonious mode of observation on volcanic rocks, and the phenomena connected with them, is the application of a uniform system of nomenclature.
In concluding these preliminary remarks, I dare express the hope that some indulgence may be had with the imperfections of this essay, if it is taken into consideration that it was written on the Pacific coast, where chemical laboratories are unknown, libraries scarce, and little opportunity is afforded of becoming acquainted with the current geological literature. I fulfill a deep-felt duty if I tender at this place my sincere thanks to Professor J. D. Whitney, not only for allowing me the use of his library and revising the manuscript of this essay, but also for the interest which he has constantly taken in my pursuits, and for what I owe to his personal intercourse, especially in a country where scientific communication is so extremely limited. The influence of this intercourse will, long after this, be kept in grateful memory by all those who are taking personally a part in the development of the California Academy, the members of which kindly allowed this paper to be published in their Memoirs. 
##############
To combine granite, quartzose porphyry, and rhyolite into one class, because they resemble each other in their chemical composition, and to place them at the head of the list because containing the highest amount of silica observed among eruptive rocks, would be to take no regard whatever of geological facts. Rhyolite is, mineralogically and geologically, far nearer related to trachyte than to either granite or quartzose porphyry ; and these two are quite distinct from each other, while granite is closely allied, by gradual passage, to syenite, and quartzose porphyry to porphyrite.
It is by slow degrees only that we can hope to reach a more scientific, that is, a more natural system in this, the most intricate branch of descriptive natural sciences.
The natural differs from the artificial system in this, that it starts from the application
(45) 8 R1CHTH0FEN THE NATURAL SYSTEM
not of one only but of various principles, compares and weighs the results obtained by each of them, and accepts them as final only when perfectly harmonizing among each other. It is then that it tries to determine what principles are most available for establishing the higher orders, and which for the subdivisions. The singular complication which is peculiar to the classification of rocks, is, besides the reasons already mentioned, due in a great measure to the fact that geology combines the double functions of a historical and an inductive science, while in petrology we have besides the requirements of a descriptive natural science. The natural system of rocks should therefore be based, not only upon the entire range of their petrographical characters, such as mineral composition, chemical composition, texture, and specific gravity, but also upon their mode of origin and geological occurrence. Classification of objects and classification of relations are, with them, closely connected, and should be made to assist each other.
Rhyolite is similar in composition and appearance to granite, but it is extrusive instead of intrusive - that is, it forms above ground instead of under it.
The word rhyolite comes from the German Rhyolith, derived by from Greek rhyax stream, stream of lava (from rhein) + German -lith -lite given to rocks by Baron Ferdinand Freiherr von Richthofen 5 May 1833 – 6 October 1905) Uncle to the Red Baron of WWI fame.
From 1862 to 1868, he worked as a geologist in the United States, discovering goldfields in California.
Between 1866-67 he wrote a book that solidified the new word in Geology Annals.
It was a hard book to find - and even then at the back of another book about moss.
books.googleusercontent.com/books/content?req=AKW5QafUSiI2A5N3cwoFO6xJS_hCYguiHwWEdR3dd5p0VNZNypT67Wl1D4Y2BfEdvW_HKzbDUZV_8HOLx1K1nw8T_ISPPiEPV83jZtHOotrQI1I1smXKgPKGGBIkkQ5mP-ZkjMrAyFThcPzIhvU7c7UoxYcV6cr_1WgWVWsrIJAqZ5_-zbp4QR88-2BkUWGUc8nqnS4ap4imBsLdLLTsU1ZXOsr43u7qeGR2XcyGRZ0TEy8QboUaSCJEDxsdEdZc-S7LhXQIg9brEuWiFHCytKI-ZNHWKOieNA
Here are the parts I particularly enjoyed:
Principles of the Natural System of Volcanic Rocks.
PRESENTED TO THE CALIFORNIA ACADEMY OF SCIENCES.
By German geologist Baron Ferdinand von Richthofen, Dr. Phil. [Presented, May 6th, 1867.]
TABLE OF CONTENTS.
. . . . . PAGE.
Introductory 1
The Natural System of Volcanic Rocks 5
Order First : Rhyolite 12
Order Second : Trachyte 17
Order Third : Propylite 20
Order Fourth : Andesite 25
Order Fifth : Basalt 26
Correlation of the Five Orders of Volcanic Rocks 28
Laws Relative to the Age of Massive Eruptions 29
Laws regarding the Mutual Relations of Massive Eruptions and Volcanic Activity 32
Relation of Volcanic Rocks to Ancient Eruptive Rocks 35
Correlation of Age and Texture 39
Correlation of Age and Composition 41
Correlation of Eruptive Rocks in regard to their Geographical Distribution 43
On the Origin of Volcanic Rocks 46
1. Origin of Massive Eruptions 47
2. Origin of Volcanic Action 60
3. Other Theories regarding the Origin of Vocalic Rocks 68
Relation of the Distribution of Volcanic Rocks to the Configuration of the Surface of the Globe 78
INTRODUCTORY.
Among the features peculiar to modern Geology may be noticed a revival of that speculative tendency which prevailed among the cultivators of this science at the close of the last century. But while in those early times imagination exerted a dominant influence in the framing of hypotheses, and discussions between the adherents of different doctrines were conducted with all the bitterness peculiar to such struggles, when neither party has a firm basis upon which to found its arguments, the constant ascendency of the spirit of the inductive method has imparted to those theories more recently propounded a more logical and scientific form, while, at the same time, the increasing amount of positive knowledge has given to the different doctrines a more varied and more definite character, and enlarged the scope of dissenting views.
############
A number of theories have been proposed, in rapid succession, relating to the origin of rocks, to the mode and causes of metamorphism, to the agencies of vulcanism, to the structure and mode of formation of mountain ranges, to the structure of the entire globe, and other cognate subjects.
It will be admitted, even by those who are most strongly opposed to theorizing, that geological science has in this way been promoted and enriched in various respects ; since there is scarcely a theory which, even if insufficient to explain what it under takes, has not some truth in it, or is applicable to some extent in certain cases, or has at least, even when proving to be erroneous itself, led to discussions on subjects of high interest, which is indeed a result of no little value. In reviewing the theories proposed on any particular subject, we find them, it is true, often in apparent contradiction with each other ; yet almost every one is based upon arguments drawn from observed facts, and there are probably very few which will ultimately be entirely abandoned. The immense range of varied processes as applied by nature allows the applicability, in a limited way, of many a theory in certain instances, while in others it may be refuted on no less valid grounds ; and the struggle between the defenders of different doctrines is often founded only in the difference of their standing-points.
What appears to be true in one instance is frequently not applicable in others ; it is the bold generalizations which render theories so often untenable in that form in which they are usually first expressed. An instructive example is presented by the different theories which have been proposed for explaining the mode of formation of mineral veins. Almost every one of them was based upon a limited range of observations, and was, from its first application to a few instances, extended to the generality of veins.
Numerous exceptions to it were then found, leading to the rejection of the first, and the establishment of a different, theory, Which, in its turn, shared a similar fate. Obscure as this subject still is, we are able to state this as certain, with our present state of knowledge, that every mineral vein is the product, not of one simple but of complex processes. Nearly every one of the theories proposed will, therefore, have its limited range of applicability, inasmuch as the agent it suggests may have 'been especially active in the formation of the veins of a certain order, while the same agent may have played a subordinate part in regard to the origin of other veins which were chiefly due to processes of another kind.
This instance points clearly towards the one principal cause of the divergence of opinions in regard to some of the most important geological questions. This cause is the want of latitude of the basis upon which arguments are founded. Conclusions which are obtained by reasoning on geological subjects solely on the strength of chemical analysis, are, when generalized, often found to be utterly in discordance with the
(40) INTRODUCTORY. 6
facts revealed by geological observation ; and how unsatisfactory general theories may be when based upon the latter alone, is sufficiently exemplified by the fantastical attempts made in all ages of geological science to interpret the geological structure of the world from that of a limited region. The basis for argumentation can therefore never be broad enough, and its enlargement should be, as it indeed is, one of the chief objects of geological science. But it is not sufficient to content ourselves with an accumulation of primary observations, which are in fact being infinitely increased by the conjoint labors of geologists in all countries : it should be a higher object of the student of geology, to compare the established results of observation, and to investigate their mutual relations. The study of the structure of one mountain range, or of several ranges comprised within a limited district, may lead to the establishment of an elaborate theory of the mode of their formation, which may apparently answer perfectly well in that one case, but may be found inadmissible when generalized, even in those cases where, by imperfect observation, one would expect to detect a great similarity to the structure first observed. But in determining those features which are common to a number of mountain ranges, or to certain orders of them which we may discern among their generality, we may aspire to form conclusions which are more generally applicable. It is particularly the auxiliary branches of geology to which these remarks apply. The value of observations made in limited regions, or from a limited point of view, on subjects such as the outlines of the morphological .feat ures of the continents, the occurrence of mineral springs, the structure of mineral veins, the age of those among them which carry a certain metal, the generality of volcanic phenomena, the mode of action of earthquakes, the nature of certain kinds of rocks, and their part in the structure of the surface of the globe—cannot be fully realized unless the comparative method is applied in as wide a scope as we may be able to do, and the mutual relations among the different modes of manifestation of force, or among the properties of the kinds of matter upon which it acts, or the bearing of all these relations to each other and to the evolution of the globe, are investigated from as many points of view as we may detect, and in as many combinations as possible.
We may then be able to gain a foundation for argumentation on more involved problems, consisting not of imperfect premises, nor of a confused accumulation of facts, but of established truths of a higher order.
##############
The mode of origin of the non-foliated crystalline rocks, made up of silicates,* is among those subjects which have at all times, but at no time more than of late, commanded a great deal of attention, and given rise to the establishment of numerous theories, each of which was applied in a general way, if not by its author, then by his followers. It is well known how conflicting they apparently are, and what weighty arguments have been brought in favor of as well as against each of them. The only method, promising success, of weighing the merits of these different theories, or of modifying them in accordance with the general advance of science, appears to be, to
* I have J"or these applied the Dame " eruptive rocks " in the following pages, considering that, wherever we have
occasion to observe them, they are not at their original seat, but ejected from it towards the surface. The reasons supporting
this position will be more fully mentioned in the chapter on the origin of volcanic rocks.
ascend from the examination of the nature of these rocks to that of their mutual relations, to investigate these from as many points of view as we can discover, in regard to physical and chemical properties, mode of occurrence and age, as well as in regard to geographical distribution : that is, to try to establish the natural system of eruptive rocks. The results so obtained may then, in accordance with what we just remarked in a general way, be applicable to reasoning on remoter questions, of which we can only attempt to find the most probable solution. They regard chiefly the causes of those relations, the mode of origin of the eruptive rocks, and the processes connected with their ejection. The intricate nature of the subject, and the fact that the present changes on and below the face of the globe, as well as the events of the past, are often but dimly and imperfectly perceptible to our observation, demand that we should concentrate our endeavors in exploring first the laws of that which is definite and constant within the infinite range of phenomena, and await further experience to arrive at an explanation of those isolated facts which form apparent exceptions to the order of things.
It is with these views that the following pages were written. They extend chiefly over the comparatively limited, and yet very extensive class of "volcanic rocks," and are offered as a mere elementary attempt, which is necessarily very imperfect.
The application to exact reasoning of the numerous observations which have been made on the subject of volcanic rocks in different countries, is nearly prevented by the extraordinary discrepancy existing in regard to the mode in which the names of rocks are used by different authors. The first condition of a uniform and harmonious mode of observation on volcanic rocks, and the phenomena connected with them, is the application of a uniform system of nomenclature.
In concluding these preliminary remarks, I dare express the hope that some indulgence may be had with the imperfections of this essay, if it is taken into consideration that it was written on the Pacific coast, where chemical laboratories are unknown, libraries scarce, and little opportunity is afforded of becoming acquainted with the current geological literature. I fulfill a deep-felt duty if I tender at this place my sincere thanks to Professor J. D. Whitney, not only for allowing me the use of his library and revising the manuscript of this essay, but also for the interest which he has constantly taken in my pursuits, and for what I owe to his personal intercourse, especially in a country where scientific communication is so extremely limited. The influence of this intercourse will, long after this, be kept in grateful memory by all those who are taking personally a part in the development of the California Academy, the members of which kindly allowed this paper to be published in their Memoirs. 
##############
To combine granite, quartzose porphyry, and rhyolite into one class, because they resemble each other in their chemical composition, and to place them at the head of the list because containing the highest amount of silica observed among eruptive rocks, would be to take no regard whatever of geological facts. Rhyolite is, mineralogically and geologically, far nearer related to trachyte than to either granite or quartzose porphyry ; and these two are quite distinct from each other, while granite is closely allied, by gradual passage, to syenite, and quartzose porphyry to porphyrite.
It is by slow degrees only that we can hope to reach a more scientific, that is, a more natural system in this, the most intricate branch of descriptive natural sciences.
The natural differs from the artificial system in this, that it starts from the application
(45) 8 R1CHTH0FEN THE NATURAL SYSTEM
not of one only but of various principles, compares and weighs the results obtained by each of them, and accepts them as final only when perfectly harmonizing among each other. It is then that it tries to determine what principles are most available for establishing the higher orders, and which for the subdivisions. The singular complication which is peculiar to the classification of rocks, is, besides the reasons already mentioned, due in a great measure to the fact that geology combines the double functions of a historical and an inductive science, while in petrology we have besides the requirements of a descriptive natural science. The natural system of rocks should therefore be based, not only upon the entire range of their petrographical characters, such as mineral composition, chemical composition, texture, and specific gravity, but also upon their mode of origin and geological occurrence. Classification of objects and classification of relations are, with them, closely connected, and should be made to assist each other.
