ISSN 1526-5757

39. Scientific errors that can result when myrmekite and geologic evidence are ignored

Lorence G. Collins

email: lorencec@sysmatrix.net

April 18, 2001

Introduction

The present studies of granitoid rocks from the 1980s into the year 2001 are dominantly directed toward chemical analyses and experimental and theoretical petrology rather than the determination of textures and petrography as seen in thin sections. Values for chemical studies of the granitoids are that they (a) support classifications into source types (S-I-A-M), (b) demonstrate liquid line of descent toward the temperature minimum of the Ab-Or-Qtz system, (c) enable the plotting of Harker diagrams of major oxides and spider diagrams of major and trace elements to show differentiation trends, (d) serve to discriminate among possible tectonic settings, and (e) provide data to enable the determination of ages by using various isotopes (Winter, 2001). For most granitoids this method of investigation is without reproach. However, when only chemical studies are used to study a granitoid, many changes in the solidified magmatic rocks may be hidden or unsuspected. Therefore, scientific errors in interpretation can result.

Recent work suggests that where the granitoids contain rim and/or wartlike myrmekite, improper assumptions can be made concerning the complete history of these rocks (Collins, Internet website articles, 1997-2001). Following solidification, deformation and modification by fluids containing K and Si can cause differentiation progressively toward the temperature minimum of the Ab-Or-Qtz system. This occurs because recrystallized minerals in granitic rocks formed by replacement processes below melting temperatures are stable there just as those formed from a melt. Moreover, the elemental characteristics of their primary magmatic sources and much of their physical features (e.g., enclaves, dikes, zoning, hypidiomorphic textures) are inherited by the metasomatized rocks so that internally and outwardly they retain much of their magmatic ancestry. The chemical analyses can look the same (or nearly so) in both magmatic or metasomatically altered granitoids, not only because of inheritance, but also because the changes in chemical compositions during metasomatism parallel what is observed in a liquid line of descent. It is only by analyzing textures, as seen in thin sections, that extensive changes in chemistry and mineralogy can be detected that are unrelated to magmatic processes. Understanding the significance of myrmekite is important because its presence in a thin section is an indication that additional study is needed in order to fully comprehend what the chemical data mean (Collins, 1988a). The historical background for the shift to modern styles of granitoid investigation and its consequences are presented below as well as problems caused by sampling bias. Because of these problems, guidelines for sampling granitoids are suggested.

Historical background

An examination of articles published since Michel-Lévy (1874) first discovered myrmekite shows trends which illustrate progressive changes in attitudes towards this unusual plagioclase-vermicular quartz intergrowth (see references listed by decades). Becke (1908) was the first to propose that myrmekite was formed by Na- and Ca- metasomatism of K-feldspar. Then, Schwantke (1910) countered with the idea that myrmekite resulted from exsolution of Na, Ca, Al, and Si from high temperature K-feldspar. Because of the conflict between these two models, myrmekite became a subject of great research interest, and investigators presented many arguments as to which one was correct. In the 1940s, 1950s, and later years, new kinds of myrmekite were described, having different kinds of textural patterns and mineral relationships. Because some textural patterns did not seem to be best explained by either of the above two models for myrmekite origin, other models for myrmekite formation were formulated. All of these early models were discussed and evaluated by Philips (1974), but none had sufficient support to say that the origin of myrmekite had been resolved.

In the 1940s through the 1960s, authors of articles on granitic rocks and gneisses commonly reported myrmekite in their petrographic descriptions, listing it as an accessory or alteration mineral along with chlorite, sericite, epidote, calcite, clay, iron oxides, apatite, allanite, titanite, and zircon. In this same period, many authors also included discussions, indicating their favored model for the origin of myrmekite. In the 1940s and 1950s, however, a great debate raged about the origin of all granite bodies, as to whether they were entirely formed (a) by subsolidus replacement processes of sedimentary rocks ("granitization") or (b) by magmatic processes. See papers by Read, Buddington, Grout, Goodspeed, and Bowen presented at a meeting of the Geological Society of America held in Ottawa, Canada, December 30, 1947 (Gilluly, 1948). The debate was subsequently won by the experimentalists, and their conclusion that all granites of large size are magmatic in origin modified opinions about myrmekite. If granite bodies were entirely magmatic in origin, then myrmekite could only be a deuteric alteration mineral that was produced during the final stages of crystallization of a magma. Moreover, because in the 1950s and 1960s, no definitive criteria had been developed to decide whether (a) Ca- and Na-replacement of K-feldspar or (b) exsolution was the correct origin of myrmekite, and because the presence of myrmekite did not seem to indicate any important relationship affecting the petrology of the granite in a major way, many authors of articles about granite in subsequent years no longer even mentioned myrmekite nor promoted their preference for its origin. Myrmekite’s tiny modal volume (generally less than 0.2 volume percent), its uncertain origin, and its relegation to a mineral formed by alteration during the last stages of crystallization of a magma seemed to suggest that myrmekite could be ignored without any serious consequences.

On that basis, interest in myrmekite waned after the 1960s, and the arguments for magmatism as the primary origin of all granite were seemingly so powerful that support for large-scale "granitization" also disappeared in most educational institutions and geological surveys and in undergraduate geology textbooks. Anyone supporting "granitization" was automatically regarded as being "behind the times." Thereafter, experimental work on granitic melts and chemical studies became the dominant accepted ways to investigate granites. Petrography and textural analysis of the rocks, as obtained through studies of microscopic thin sections, were relegated to the "trash heap," and editors of journals were not interested in publishing such information. In place of thin section studies, chemical analyses of major oxides and trace elements, and theoretical and experimental petrology based on thermodynamics became the dominant emphasis. Cathodoluminescent techniques, fluorescent x-ray, and scanning- and electron-microprobe methods of analysis soon replaced wet-chemical methods to determine chemical compositions, and the addition of isotopic age-dating methods, using various isotopes, became the accepted ways to study granitic rocks (Winter, 2001).

On the basis of these modern methods of studying granitic rocks, published articles in the decades since the 1970s contain little mention of petrography. Once it had been decided that all granites were magmatic in origin, the study of petrography was no longer needed, and any hypothesis suggesting that not all granites were totally magmatic in origin was not even considered. With this mind set, many articles, describing the chemistry or isotopic compositions of granitic rocks, mention only the main component minerals. No detailed descriptions of textures occur, and the barest information about accessories or alteration minerals is given, if at all. Even in other articles not emphasizing chemistry, progressively through the decades since the 1960s, myrmekite commonly is omitted from the petrography sections, even when it is relatively abundant. This is in spite of the fact that other alteration minerals are reported. When other alteration minerals are mentioned but not myrmekite, the lack of noting myrmekite is an example of scientific negligence. All mineral data, including myrmekite, should be reported when describing rocks even if the authors do not regard myrmekite as being important.

In the 1960s and 1970s, research on myrmekite was in limbo. Because it was felt by editors of journals that myrmekite had been thoroughly studied, articles on this topic were generally rejected. Even abstracts submitted for presentation at professional conventions were rejected because the reviewers felt that attendees would not be interested in them. However, many geologists were still not satisfied with the then-available models for the origin of myrmekite, and, surprisingly, a few articles proposing new models continued to appear in the literature in the 1980s and 1990s as new kinds of myrmekitic textures were found in different rock types. See the reference list by decades.

Beginning in 1972, my own work supported the general feeling that all large masses of granitic rocks have been emplaced by magmatic processes and that no large granite mass has formed by subsolidus "granitization" of sedimentary rocks. However, in the late 1970s, 1980s, and 1990s evidence became available to me that some large plutonic igneous masses, after emplacement and solidification, have been modified by K- and Si-metasomatism to change them into rocks of a more-granitic composition, having increasing percentages of K-feldspar and quartz (Collins, 1988a; Hunt et al., 1992; Collins website articles at http://www.csun.edu/~vcgeo005). In a few places, even adjacent metasedimentary wall rocks had undergone similar and simultaneous K- and Si-metasomatism as the magmatically emplaced pluton was metasomatized. This metasomatism required deformation of solid rocks below melting temperatures in order to create tiny fractures in which fluids could enter and interact with the primary minerals in the rocks. These fluids utilized local or outside sources of K and Si and removed some Ca, Al, Fe, and Mg among other elements from the rocks. No migration of these elements was by solid-state diffusion through undeformed rocks across vast distances (meters and kilometers) as was assumed to occur by some geologists during the old style "granitization" process. The only amount of solid-state diffusion was on a scale much less than a millimeter and only through half the diameter between closely-spaced, microscopic fractures within a mineral grain. Significantly, the tiny fractures created by deformation generally have gone unnoticed by petrologists because such brittle breakage of plagioclase crystals cannot be seen in thin section under plane or cross-polarized light. Only strong deformation that bends albite twin lamellae or cataclasis that rotates broken fragments is observed under cross-polarized light. Seeing these tiny fractures requires cathodoluminescence imaging, which is a technique that petrologists have not commonly applied to the study of granitic textures (Hopson and Ramseyer, 1990a; Collins, 1997b). Consequently, these clues to the K-metasomatism have been missed. At any rate, the main means of elemental migration must be in fluids moving through fractures and by ionic diffusion through these fluids rather than by solid-state diffusion. The residual effects of ion exchanges along the fractures during these movements are readily seen in cathodoluminescent images. Subsequently, the element identification along such fractures can be verified with scanning- and electron-microprobe analyses (Collins, 1997b).

Resistance to this new K- and Si-metasomatic model was enormous and increasingly so after the 1970s to the year 2001 because the general feeling among most granite petrologists is that "granitization" had been disproved. K- and Si-metasomatism must have sounded like "granitization" all over again, even though it was entirely different. Assumptions were made by most petrologists that when a magmatically-emplaced granitic body became crystallized, it was static, and, henceforth, it did not change (except by weathering), even for billions of years. Therefore, any hypothesis suggesting large-scale changes by metasomatic fluids was wrong. While agreeing with the conclusion that all granitoids are emplaced and crystallized from magmas, I suggested that the thin section evidence, field studies, and chemical analyses (including electron-microprobe analyses) showed that large-scale K- and Si-metasomatism is valid in some deformed plutonic masses, and myrmekite is the clue to this metasomatism (Collins, 1988a). Nevertheless, the increasing resistance to a model that sounded like "granitization" has continued in the 1970s, 1980s, and 1990s, regardless of the evidence that was provided.

Objection to large-scale K- and Si-metasomatism is surprising for the following reasons.

(1) Granite petrologists have already accepted large-scale Na-metasomatism during fenitization (Winter, 2001), and the chemistry of Na is not much different from that of K so that both should behave in the same way. Examples of large-scale Na-metasomatism in granitic rocks are demonstrated in northern New York (Collins, 1997r).

(2) Large-scale K-replacement of plagioclase crystals (from the exterior inward) is known to occur throughout some granitic plutons during late-stages of the crystallization of the magma (Collins, 1997s). Therefore, lowering the temperature just a few degrees below melting conditions should not change the capability of K to replace plagioclase. However, the style of replacement changes to that of replacing the plagioclase crystals from the interior outward rather than from the exterior inward. The difference in style occurs because in magma, not totally solidified, the ability of fluids to flow between early-formed crystals creates space for the expanded, lower-density lattice of K-feldspar to grow as it replaces the denser lattice of plagioclase. In contrast, in completely crystallized granitoids, no expansion between sealed and interlocking solid crystals can occur. First fracturing must occur, and then the extra needed space for the K-feldspar lattice to form must be produced by removal of elements from the interiors of the deformed plagioclase crystals. As replacement occurs, it is not mass-for-mass, as in balanced chemical equations, but volume-for-volume (Collins, 1988a, 1997a, 1997b).

(3) Experimental work of Orville (1962, 1963) has already shown that K-metasomatism can be demonstrated and that it occurs at rates that permit the conversion of plutonic rocks containing plagioclase as the only feldspar into granite containing K-feldspar during the geologic time frames that are available (Collins, 1999b).

And finally, (4) economic geologists have observed the broad extent of metasomatism by large quantities of introduced fluids to form many different kinds of metallic ore deposits. Having seen the evidence for such great volumes of "metal" replacements in deformed but solid rocks, our colleagues find it surprising that granite petrologists do not accept large-scale K-metasomatism (Tim H. Bell, email communication, 1997).

The problem for accepting large-scale K- and Si-metasomatism to form some granitoids is partly because granite petrologists have not seen the evidence in thin section via cathodoluminescent imaging and because they have been looking in the wrong places, as is suggested in the next section.

Sample bias

There is an anecdote about a person in the middle of the night coming upon an old man on his knees under a street lamp looking for his glasses. After learning of the man’s loss, this person decides to help in the hunt. After several minutes of looking, however, and finding nothing, this person asks: "Where did you lose your glasses?" The old man points to the dark shadows and says: "Over there." "Then, why are you looking here?" To which the man replied: "Because the light is here."

This anecdote illustrates an analogous problem in studying myrmekite. Myrmekite-bearing granitic rocks generally form resistant outcrops because of the abundance of quartz and feldspars. The outcrops of granite ("where the light is") stand above the valleys ("the shadows where the origin of myrmekite can be found"). In this analogy the investigators of myrmekite have looked only in the granite where the final product has been produced and not where the progressive stages that led to the formation of the myrmekite have taken place. One must look beyond the granite in the transition rocks where biotite is commonly abundant to find the answer to the origin of myrmekite. Unfortunately, biotite-rich rocks are easily weathered and eroded, and in many places glaciers and streams have removed these weaker rocks, and vegetation, soil, and other deposits cover them. Thus, natural processes force a sample bias on the person wanting to collect rocks in a given terrain. Only the resistant rocks in outcrop can be collected unless diamond drilling of covered rocks is used to obtain core samples. Because of this limitation, in many places only the final product of K- and Si-metasomatism can be collected, forcing an unfortunate sample bias. Moreover, in many places the replacements and recrystallization of the original rock found in the resistant outcrop have removed nearly all evidence for its original composition and for its former deformation that permitted the K- and Si-metasomatism.

Another bias in sampling occurs because modern studies of granites deal with their chemistry and isotopic compositions. Rocks needed for these investigations must be fresh, and only a few samples are required. When the investigator already believes ("knows") that the granite is entirely magmatic in origin, there is no purpose in collecting lots of samples to prove its magmatic origin, and samples that might be weathered or messy are avoided. Two thin sections may be sufficient to determine the main minerals. Yet, it is the abundance of samples in the wall rocks and transitions to the granite and their thin sections (the geologic evidence) that may reveal the true history of the rock.

Guidelines for sampling granitoids

On that basis, to avoid sampling bias certain rules should be followed when collecting samples of granitic rocks.

1. The sampling must be systematic, making sure that a grid distribution of samples is obtained wherever the outcrops make it possible.

2. Even though the granitoid may appear to be uniform (magmatic in appearance), two samples need to be taken at each collection site in a grid in order to see the local and broad variations that occur. Where a granitoid is not uniform, all rock types should be collected at a given grid site.

3. Where foliation is present, strike and dip must be measured, and the sample that is collected must be taken from the same place that the rock attitude is determined. The structural attitude of the sample relative to attitudes of rocks in surrounding or adjacent areas may determine the sample’s mineral and chemical composition because the composition may result from metasomatic fluids moving into low pressure sites that are controlled by the structure.

4. Exotic structures and textures (enclaves, schlieren, etc.) are commonly attractive, and the investigator must be careful in the field not to bias the sampling by making a collection consisting of 80-90 percent of the exotic rocks and 10-20 percent from the common rock type. The sampling should be proportional to the relative volumes of the different rock types.

5. Efforts must be made to find and collect from transition rocks. For example, (a) if the granitic rock contains K-feldspar megacrysts, then transitions to portions of the granitic body must be looked for in which the megacrysts are absent. (b) If the K-feldspar megacrysts are zoned, then transitions to places where they lack zoning must be sought. (c) If pegmatite dikes are found, then the dikes need to be walked out along strike to see if they grade into zones of deformation and then to where the dikes and deformation disappear. And (d), similarly, if migmatites occur, the granitic portions need to be sampled progressively along strike until the granitic rocks disappear. Samples of these different kinds of transition rocks are likely to provide clues to the evolutionary history of the granitoid.

Because myrmekite cannot be seen in the field, when it is discovered later in thin section, one should go back in the field, perhaps several times, to collect additional samples and narrow down the transitions to where myrmekite first appears. Because perthitic intergrowths also cannot be seen in the field, if the albite lamellae in the K-feldspar are not uniformly distributed and are irregular in size, then additional sampling is needed. If the perthite lamellae have uniform distribution and are nearly constant in size, then they are likely formed by exsolution from orthoclase. If the lamellae are not uniform, this perthite could be formed from replacement of plagioclase by K-feldspar. Return trips may also show progressive Si-replacements, producing interior quartz blebs in hornblende and biotite across the transitions. At any rate, without such a guideline to seek transition areas, these many different things to look for might be missed if the investigator has preconceived notions that the granitoid is entirely magmatic and unchanged since emplacement. As Goethe said: "We see what we know."

Some of these sampling rules may go against one’s natural tendencies in the field. In some places great numbers of samples do not seem to be necessary. I have had to remind myself many times to follow these rules when my instincts said: "What is the use of sampling here?" However, the unaided eye can not see mineralogical and textural changes that are important. Moreover, I discovered that it was only when I collected hundreds of samples systematically and made thin sections of these samples that structural attitudes at outcrops could be tied to metasomatism. It was only when I collected 900 samples of amphibolite and interlayered biotite-orthopyroxene-plagioclase (An80) gneiss in eight different layers from noses to limbs in isoclinal folds did the thin sections and other methods of analysis reveal convincing evidence for progressive losses of iron from the ferromagnesian silicates in deformed amphibolite in the limbs (Collins, 1969). These losses explained how magnetite concentrations were formed in sufficient quantities to be mined as iron ore. This same extensive sampling also showed the progressive changes in the limbs in the deformed biotite-orthopyroxene-plagioclase gneisses to convert them into myrmekite-bearing granitic gneisses. Likewise, in other terranes it has been only when great numbers of samples were collected from areas outside a granite body through transitions into the granite that I could observe the progressive stages of myrmekite formation. See index of articles in the Internet URL: http://www.csun.edu/~vcgeo005/index.html

Conclusion

On the basis of the above, new attention needs to be applied to thin section studies of more than a few samples and to the occurrence and absence of myrmekite in granitic rocks. Although granitic plutons are emplaced by magmatic processes, that does not mean that these rocks will necessarily remain unchanged through eons following their solidification. The constant stirring in the mantle, causing crustal plate motions, must deform at least some of the crystallized plutons, enabling metasomatic fluids to move through them. It is agreed that using only petrographic studies of thin sections is inadequate to explain what happens in the plutons during their entire evolutionary history. But so also is a study limited to chemical analyses inadequate. Investigators need to combine experimental, chemical, and theoretical studies with geologic evidence obtained in the field and from detailed thin section analysis, concomitant with cathodoluminescence studies, if scientific errors in interpretation are to be avoided.

References by decades

1870s

Michel-Lévy, A. M., 1874, Structure microscopique des roches acides anciennes. Société Francaise de Mineralogie et de
Crystallographie, Bulletin, v. 3, p. 201-222.

1900s

Becke, F., 1908, Über myrmekit: Mineralogie und Petrographie Mitteilungen, v. 27, p. 377-390.
Schwantke, A., 1909, Die Beimischung von Ca in Kalifeldspat und die Myrmekitbildung: Zentblatt für Mineralogie,
p. 311-316.

1910s

Eskola, P., 1914, On the petrology of the Orijarvi Region in south-western Finland: Bulletin de la Commission geologique
de Finlande, No. 40.
Sederholm, J. J., 1916, On synantectic minerals and related phenomena: Bulletin de la Commission geologique de Finlande,
v. 9, p. 1-152.

1930s

Anderson, A. L., 1934, Contact phenomena associated with the Cassia batholith, Idaho: Journal of Geology, v. 42, p.
376-392.
Anderson, G. H., 1934, Pseudocataclastic texture of replacement origin in igneous rocks: American Mineralogist, v. 19, p.
185-193.
Anderson, G. H., 1937, Granitization, albitization, and related phenomena in the northern Inyo Range of California-Nevada:
Geological Society of America Bulletin, v. 48, p. 1-74.
Gilluly, J., 1931, Replacement origin of the biotite granite near Sparta, Oregon: U.S. Geological Survey Professional
Paper 175-C, p. 65-81.
Hills, E.S., 1933, An unusual occurrence of myrmekite, and its significance: Geological Magazine, v. 70, p. 294-301.
Stark, J. T., 1935, Migmatites of the Sawatch Range, Colorado: Journal of Geology, v. 43, p. 1-26.

1940s

Anderson, A. L., 1942, Endomorphism of the Idaho Batholith: Geological Society of America Bulletin, v. 53, p. 1099-1126.
Anderson, A. L., Hammerand, V., 1940, Contact and endomorphic phenomena associated with a part of the Idaho batholith:
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Bugge, J. A. W., 1943, Geological and petrological investigations in the Kongsberg-Bamble Formation: Norges Geologiske
Undersokelse Nr. 160, 150 p.
Cheng, Y., 1944, The migmatite area around Bettyhill, Sutherland: Quarterly Journal of the Geological Society of London,
v. 99, p. 107-148.
Drescher-Kaden, F. K., 1948, Die Feldspat-Quartz Reactions-gefuge der Granite und ihre
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Edelman, N., 1949, Microcline porphyroblasts with myrmekite rims: Bulletin de la Commission geologique de Finlande No.
144, p. 73-79.
Gault, H. R., 1945, Petrography, structure, and petrofabrics of the Pinckneyville quartz diorite, Alabama: Geological Society
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Gilluly, J., (chairman), 1948, Origin of Granite, Conference at meeting of the Geological Society of America held in Ottawa,
Canada, December 30, 1947: Geological Society of America Memoir 28, 139 p.
Gummer, W.K., 1941, Border rocks of a granite batholith, Red Lake, Ontario: Journal of Geology, v. 49, p. 641-656.
Hietanen, A., 1947, Archean geology of the Turku district in southwestern Finland: Geological Society of America
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Krauskopf, K. B., 1943, The Wallowa batholith: American Journal of Science, v. 241, p. 607-628.
Pavlov, N. V., and Karskii, B. E., 1949, Myrmekite in basic rocks: Ivestiya Akademii Nauk SSSR Seriya Geologisches-
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Perrin, R., 1949, On the granite problem: Journal of Geology, v. 57, p. 357-379.
Postel, A. W., 1940, Hydrothermal emplacement of granodiorite near Philadelphia: Proceedings of the Academy of
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Reynolds, D. L., 1943, The south-western end of the Newry igneous complex. A contribution towards the petrogenesis of the
granodiorite: Abstracts and Proceedings of the Geological Society of London, no. 1396, p. 74-81.
Reynolds, D. L., 1946, The sequence of geochemical changes leading to granitization: Quarterly Journal of the
Geological Society of London, v. 102, p. 389-446.
Spencer, E., 1945, Myrmekite in graphic granite and in vein perthite: Mineralogical Magazine, v. 27, p. 79-98.
Waters, A. C., and Krauskopf, K., 1941, Protoclastic border of the Colville batholith: Geological Society of America
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Wilson, A. F., 1947, The charnockitic and associated rocks of northwestern south Australia, Part I, The Musgrave Ranges -
an introductory account: Transactions of the Royal Society of South Australia, v. 71, p. 195-211.

1950s

Bowes, D. R., 1954, The transformation of tillite by migmatization at Mount Fitton, South Australia: Quarterly Journal of
the Geological Society of London, v. 109, p. 455-481.
Harme, M., 1958, Examples of the granitization of plutonic rocks: Bulletin de la Commission geologique de Finlande no.
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Kullerud, G., and Neumann, H., 1953, The temperature of granitization in the Rendals-Vik area, northern Norway: Norsk
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Parras, K., 1958, On the charnockites in the light of a highly metamorphic rock complex in southwestern Finland: Geologinen
Tutkimuslaitos, Bulletin de la Commission Geologique de Finlande, no. 181.
Perrin, R., 1954, Granitization, metamorphism, and volcanism: American Journal of Science, v. 252, p. 449-465.
Quensel, P., 1950, The charnockite series of the Varberg district on the south-western coast of Sweden: Arkiv for Mineralogi
och Geologi, Band 1, nr. 10, p. 227-322.
Sarma, S. R., and Raja, N., 1958, Some observations on the myrmekite structures in Hyderabad granites: Quarterly Journal
of the Geological, Mineralogical, and Metallurgical Society of India, v. 30, p. 215-220.
Sarma, S. R., and Raja, N., 1959, On myrmekite: Quarterly Journal of the Geological, Mineralogical, and Metallurgical
Society of India, v. 31, p. 127.
Schermerhorn, L. J. G., 1956, The granites of Trancoso (Portugal): a study in microclinization: American Journal
of Science, v. 254, p. 329-348.
Schreyer, W., 1958, Die Quarz-Feldspat-Gefüge der migmatischen Gesteine von Vilshofen an der Donan: Neues Jahrbuck für
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Seitsaari, J., 1951, The schist belt northeast of Tampere in Finland: Bulletin de la Commission geologique de Finlande,
v. 153, p. 1-120.
Skjeseth, S., and Sorensen, H., 1953, An example of granitization in the central zone of the Caledonides of northern Norway:
Norges Geologiske Underskelse, no. 184, p. 154-183.
Surya Narayana, K. V., 1956, The nature of the potash feldspar in relation to myrmekite in Clospet granites: Journal of
Mysore University, v. 25, part 12, p. 97-106.

1960s

Augustithis, S. S., 1962, Non-eutectic, graphic, micrographic and graphic-like "myrmekitic" structures
and intergrowths: Beitrage zur Mineralogie und Petrographie, v. 8, p. 491-498.
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Carman, J. H., and Tuttle, O. F., 1963, Experimental study bearing on the origin of myrmekite (abstract): Geological
Society of America Abstracts, Annual Meeting, p. 29A.
Castle, R. O., 1966, Origin of myrmekite: Geological Society of America Special Paper 87, (abstract), p. 198.
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203.
Chatterjee, S. C., 1965, The anorthosites near Turkel in Kalahandi District, Orissa, and the associated Khondalites
and granite gneisses: D. M. Wadia Commerative Volume (Min. Geol. & Met. Institute, India), p. 381-393.
Collins, L. G., 1969, Regional recrystallization and the formation of magnetite concentrations, Dover magnetite
district, New Jersey: Economic Geology, v. 64, p. 17-33.
Garg, N. K., 1967, Myrmekite in charnockite from southwest Nigeria: a discussion: American Mineralogist, v. 52, p.
918-920.
Goodspeed, R. M., 1969, The origin of myrmekite in the Precambrian plutonic granites in a portion of the New Jersey
Highlands: Geological Society of America Abstracts with Programs, v. 1, p. 22.
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Geological Congress, 23rd, Prague, Proceedings, Section 4, p. 275-292.
Hietanen, A., 1962, Metasomatic metamorphism in western Clearwater County, Idaho: U.S. Geological Survey Professional
Paper 344-A, p. 1-116.
Hofmann, A., 1967, Alkali infiltration metasomatism in feldspar solid solutions: American Geophysical Union Transactions,
v. 48, p. 230.
Hubbard, F. H., 1966, Myrmekite in charnockite from southwest Nigeria: American Mineralogist, v. 51, p. 762-773.
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Hubbard, F. H., 1967b, Exsolution myrmekite; a proposed solid-state transformation model: Geologiska Forenigens i
Stockholm Forhandlingar, v. 89, p. 410-422.
Hubbard, F. H., 1969, The proportionality of quartz in myrmekite: a contribution to the discussion: American
Mineralogist, v. 54, p. 988-989.
Orville, P. M., 1962, Alkali metasomatism and feldspars: Norsk Geologisk Tiddskrift, v. 42, p. 283-316.
Orville, P. M., 1963, Alkali ion exchange between vapor and feldspar phases: American Journal of Sciences, v. 261,
p. 201-237.
Phillips, E. R., 1964, Myrmekite and albite in some granites of the New England Batholith, New South Wales: Journal of the
Geological Society of Australia, v. 11, p. 49-59.
Phillips, E. R., and Ransom, D. M., 1968, The proportionality of quartz in myrmekite: American Mineralogist, v. 53,
p. 1411-1413.
Ramaswamy, A., and Murty, S., 1968, Myrmekite from pyroxene granulite: Bulletin Geochemical Society of India,
v. 3, p. 45-47.
Ramberg, H., and Widenfalk, L., 1968, Bildning av myrmekit: Geologiska Foereningen I Stockholm Foerhandlingar, v.
90, no. 534, p. 470.
Ransom, D. M., and Phillips, E. R., 1969, The proportionality of quartz in myrmekite: a reply: American Mineralogist,
v. 54, p. 984-987.
Rao, Y. J., and Raju, C. S., 1964, Diffusion through plagioclase feldspars and its bearing on myrmekite formation: Current
Science, v. 33, p. 307-309.
Rao, Y. J., and Raju, C. S., 1969, Myrmekites in granitic rocks of Srikakulam district, Andhra Pradesh: Current Science,
v. 38.
Sahu, K. N., 1968, On myrmekites of hypersthene granites of Tapang, Orissa: Proceedings of the Indian Science Congress,
p. 229.
Sathe, R. V., 1964, A note on cotectic myrmekites from Jothwod granite, Panchmahal District, Gujrat: Science and
Culture, No. 30, p. 334-337.
Schermerhorn, L. J. G., 1960, Telescoping of mineral facies in granites: Bulletin de la Commission geologique de
Finlande, No. 188, p. 121-132.
Shelley, D., 1964, On myrmekite: American Mineralogist, 49, p. 41-52.
Shelley, D., 1966, The significance of granophyric and myrmekitic textures in the Lundy granites: Mineralogical Magazine,
v. 35, p. 678-692.
Shelley, D., 1967, Myrmekite and myrmekite-like intergrowths: Mineralogical Magazine, v. 36, p. 491-503.
Shelley, D., 1969, The proportionality of quartz in myrmekite: a discussion: American Mineralogist, v. 54, p. 982-984.
Siddhanta, S. K., and Akella, J., 1966, The origin of myrmekites in hornblende-plagioclase gneisses and in the associated
pegmatites: Acta Geologica Hungarica, v. 10, p. 31-52.
Tufar, W., 1966, Bemerkenswerte Myrmekite aus Erzvorkommen vom Alpen-Ostrand: Neues Jahrbuch für Mineralogie
Monatshefte, v. 8, p. 246-252.
Voll, G., 1960, New work on petrofabrics: Liverpool and Manchester Geological
Journal, v. 2, part 3, p. 503-567.
Widenfalk, L., 1969, Electron micro-probe analyses of myrmekite plagioclase and coexisting feldspars: Lithos, v. 2, p.
295-309.

1970s

Ashworth, J. R., 1972, Myrmekites of exsolution and replacement origin: Geological Magazine, v. 109, p. 45-62.
Ashworth, J. R., 1973, Myrmekites of exsolution and replacement origins: a reply: Geological Magazine, v. 110,
p. 77-80.
Barker, D. S., 1970, Compositions of granophyre, myrmekite, and graphic granite: Geological Society of America Bulletin, v.
84, p. 3339-3350.
Bhattacharyya, C, 1971, Myrmekite from the charnockitic rocks of the Eastern Ghats, India: Geological Magazine, v. 108, p.
433-438.
Bhattacharyya, C, 1972, Myrmekite from the charnockitic rocks of the Eastern Ghats, India: a reply: Geological Magazine, v.
109, p. 371-372.
Byerly, G. B., and Vogel, T. A., 1973, Origin of rimming, antiperthite and myrmekite in metamorphic plagioclase
(abstract): EOS, American Geophysical Union, Transactions, v. 54, no. 4, p. 509.
Carr, G. R., and Phillips, E. R., 1973, On exsolution myrmekite: Carstens, H., 1967, Exsolution in ternary
feldspars: II. Intergranular precipitation in alkali feldspar containing calcium in solid solution: Contributions to Mineralogy and Petrology, v. 14, p. 316-320.
Didwal, R. S., 1970, On the origin of myrmekites in granitoid rock of Doda district, Jammu & Kashmir State: Geoviews,
v. VII, no 1, p. 13-20.
Dusel-Bacon, C., 1979, Preliminary results of an augen gneiss study, Big Delta quadrangle: U.S. Geological Survey Circular,
v. 804 B, p. 57-59.
Ghosh, D., 1976, On the myrmekites from the granite gneiss of Doranda, Hazaribagh District, Bihar: Journal of the Geological
Society of India, v. 17, no. 2, p. 201-206.
Gupta, L. N., 1970, Evolution of myrmekites: Bulletin Indian Geologists’ Association, v. 3, p. 31-32.
Hibbard, M. J., 1979, Myrmekite as a marker between preaqueous and postaqueous phase saturation in granitic systems:
Geological Society of America Bulletin, v. 90, Part I, p. 1047-1062.
Hunter, D. B., 1976, On some potassium feldspars in the Precambrian granitic rocks of Swaziland, v. 76, p. 63-73.
Joergart, T., 1970, On the late formation of plagioclase in granitic rocks: Dansk Geologisk Forening, Meddelelser, v. 20,
no. 1, p. 69-71.
Kazak, A. P., 1973, Problem of the origin and age of augen gneiss in the Mediterranean basin: Doklady Akademii Nauk
SSSR, v. 212, p. 1416-1419.
Laurent, R., 1973, The origin and kinematic evolution of a metasomatic granite of the Aiguilles Rouges, western Alps:
Special Publication of the Geological Society of South Africa 3, p. 499-505.
Makhlayev, L. V., 1973, In reference to the genesis of myrmekites: International Geology Reviews, v. 15, p. 179-182.
Marmo, V., 1971, Granite petrology and the granite problem: Elsevier, Amsterdam, 244 p.
Myers, J. S., 1978, Formation of banded gneisses by deformation of igneous rocks: Precambrian Research, v. 6,
p. 43-64.
Phillips, E. R., 1972a, Myrmekite from the charnockitic rocks of the Eastern Ghats, India: a discussion: Geological
Magazine, v. 109, p. 371.
Phillips, E. R., 1972b, Compositions of granophyre, myrmekite, and graphic granite: discussion: Geological Society
of America Bulletin, v. 83, p. 249-250.
Phillips, E. R., 1972c, Myrmekites of exsolution and replacement origins: a discussion: Geological Magazine, v. 110,
p. 74-77.
Phillips, E. R., 1973, Myrmekites from the Haast schists, New Zealand: a discussion: American Mineralogist, v. 58,
p. 802-803.
Phillips, E. R., 1974, Myrmekite - one hundred years later: Lithos, v. 7, p. 181-194.
Phillips, E. R., and Carr, G. R., 1973, Myrmekite associated with alkali feldspar megacrysts in felsic rocks from
New South Wales: Lithos, v. 6, p. 245-260.
Phillips, E. R., and Ransom, D. M., 1970, Myrmekitic and non-myrmekitic plagioclase compositions in gneisses from
Broken Hill, New South Wales: Mineralogical Magazine, v. 37, p. 729-732.
Phillips, E. R., Ransom, D. M., and Vernon, R. H., 1972, Myrmekite and muscovite developed by retrograde metamorphism
at Broken Hill, New South Wales: Mineralogical Magazine, v. 38, p. 570-578.
Phillips, E. R., and Stone, I. J., 1974, Reverse zoning between myrmekite and albite in a quartzofeldspathic gneiss from
Broken Hill, New South Wales: Geological Magazine, v. 39, p. 654-657.
Ramaswamy, A., and Murty, S., 1972, Myrmekite from the charnockite series of Amaravathi, Guntur district, Andhra
Pradesh: Journal of the Geological Society of India, v. 13, p. 273-276.
Robertson, I. D. M., 1978, Potash granites of the southern edge of the Rhodesian craton and the northern granulite zone of
the Limpopo mobile belt: Special Publication of the Geological Society of South Africa 3,p. 265-276.
Shelley, D., 1970, The origin of myrmekite intergrowths and a comparison with rod-eutectics in metals: Mineralogical
Magazine, v. 37, p. 674-681.
Shul'diner, V. I., 1972, The problem of myrmekites: International Geology Review, v. 14, p. 354-358.
Shelley, D., 1973a, Myrmekites from the Haast schists, New Zealand: American Mineralogist, v. 58, p. 332-338.
Shelley, D., 1973b, Myrmekites from the Haast schists, New Zealand: a reply: American Mineralogist, v. 58, p. 804.

1980s

Ashworth, J. R., 1986, Myrmekite replacing albite in prograde metamorphism: American Mineralogist, v. 71, p. 895-899.
Chadha, D. K., 1980, On the formation of myrmekite in the Chaur sub-foliated granite, Simla Hills, India: Recent Research
in Geology (India), v. 6, p. 325-329.
Collins, L. G., 1983, Myrmekite formed by recrystallization of plagioclase and its implications for the origin
of some granitic rocks: Geological Society of America Abstracts with Program, v. 15, no. 5, p. 420.
Collins, L. G., 1988a, Hydrothermal Differentiation And Myrmekite --- A Clue To Many Geologic Puzzles: Theophrastus
Publications S.A., Athens, Greece, 382 pp.
Collins, L. G., 1988b, Myrmekite, a mystery solved near Temecula, Riverside County, California. California
Geology, v. 41, p. 276-281.
Collins, L. G., 1989, Origin of the Isabella pluton and its enclaves, Kern County, California: California Geology,
v. 42, p. 53-59.
Dymek, R. F., and Schiffries, C. M., 1987, Calcic myrmekite: possible evidence for the involvement of water during the
evolution of andesine anorthosite form St. Urbain, Quebec: Canadian Mineralogist, v. 25, p. 291-319.
Guha, D. B., and Gupta, L. N., 1986, Electron microscopic investigations of perthite, myrmekite and rapakivi structures
in feldspars occurring in the granitic rocks of the Doda area, Journal of the Geological Society of India, v. 27, no. 2, p. 220-222.
Heikal, M. A., Attawiya, M. Y., and El-Sheshtawi, Y. A., 1985, Textural patterns, geochemistry and origin of the
granitoid rocks around Wadi, El-Shiekh, southwestern Sinai, Egypt: Annals of the Geological Survey of Egypt, v. 15, p. 197-210.
Hibbard, M. J., 1980, Myrmekite as a marker between preaqueous and postaqueous phase saturation in granitic systems:
reply: Geological Society of America Bulletin, v. 91, Part I, p. 673-674.
Hibbard, M. J., 1987, Deformation of incompletely crystallized magma systems: Granitic gneisses and their tectonic
implications: Journal of Geology, v. 95, p. 543-561.
Hietanen, A., 1986, Role of replacement in the genesis of anorthosite in the Boehls Butte area, Idaho: Bulletin of the
Geological Society of Finland, v. 58, part 1, p. 71-79.
Kresten, P., 1988, Granitization - fact or fiction?: Geologiska Foreningens i Stockholm Forhandlingar, v. 100, pt. 4,
p. 335-340.
La Tour, T. E., 1987, Geochemical model for the symplectic formation of myrmekite during amphibolite-grade progressive
mylonitization of granite: Geological Society of America, Abstracts with Programs, v. 19, p. 741.
LaTour, T. E., and Barnett, R. L., 1987, Mineralogical changes accompanying mylonitization in the Bitterroot dome of
the Idaho batholith: implications for timing of deformation: Geological Society of America Bulletin, v. 98, p. 356-363.
La Tour, T. E., Thomson, M. L., 1988, Myrmekite as a transitional stage of K-feldspar breakdown; in J. S. Kallend, J.
S., and Gottstein, G., (eds.), Eighth International Conference on Textures of Materials (ICOTOM 8): The Metallurgical Society, p. 817.
Mehnert, K. R., 1987, The granitization problem - revisited: Fortschrift Mineralogie, v. 65, p. 285-306.
Moore, D. E., 1987, Syndeformational metamorphic myrmekite in granodiorite of the Sierra Nevada, California: Geological
Society of America Abstracts with Programs, v. 19 (7), p. 776.
Nold, J. L., 1981, Myrmekite in metasedimentary rocks: Missouri Academy of Science, Transactions, v. 15, p. 244.
Nold, J. L., 1984, Myrmekite in Belt Supergroup metasedimentary rocks – northeast border zone of the Idaho Batholith:
American Mineralogist, v. 69, p. 1050-1052.
Phillips, E. R., 1980a, On polygenetic myrmekite. Geological Magazine, v. 117, p. 29-36.
Phillips, E. R., 1980b, Myrmekite as a marker between preaqueous and postaqueous phase saturation in granitic systems:
discussion: Geological Society of America Bulletin, Part I, v. 91, p. 672-673.
Rafiq, M., Khan, M. A., Jan, M.Q., 1988, Myrmekite in the Ambela granitic complex, N. Pakestan; a product of deformation
and replacement in the feldspars: Geological Bulletin, University of Peshawar, v. 21, p. 159-165.
Robertson, S., 1984, Textures of Archean granites, Ivisartoq region, southern West Greenland: Report of activities
1983; Report – Geological Survey of Greenland, v. 120, p. 67-70.
Schiffries, C. M., and Dymek, R. F., 1985, Calcic myrmekite in anorthositic and gabbroic rocks: Geological Society of
America Abstracts with Programs, v. 17, p. 709. (annual meeting in Orlando, Florida)
Simpson, C., 1985, Strain related myrmekitic intergrowths in mylonites: Geological Association of Canada/Mineralogical
Association of Canada, Programs with Abstracts, v. 10, p. A56.
Simpson, C., 1985, Deformation of granitic rocks across the brittle-ductile transition: Journal of Structural Geology,
v.7, p. 503-511.
Simpson, C., and Wintsch, R. P., 1989, Evidence for deformation-induced K-feldspar replacement by myrmekite:
Journal of Metamorphic Geology, v. 7, p. 261-275.
Srivastava, D. K., and Karkare, S. G., 1987, Myrmekite in Bastar granitoids and their genesis: Records of the
Geological Society of India, v. 118, p. 74-75.
Tadkod, M., 1989, Geochemistry of main rock types and petrogenesis of myrmekite from Hells-Roaring Lakes area,
Montana: Geological Society of America, 1989 annual meeting, Abstracts with Programs, v. 21, no. 6, p. 276.
Vidal, J. Kubin, L., Debat, P., and Soula, J., 1980, Deformation and dynamic recrystallization of K-feldspar
augen in orthogneiss from Montagne Noire, Occitania, southern France: Lithos, v. 13, p. 247-255.
Winchester, J. A., and Max, M. D., 1984, Element mobility associated with syn-metamorphic shear zones near Scotchport,
NW Mayo, Ireland: Journal of Metamorphic Geology, v. 2, p. 1-11.
Yuezhi, C., 1980, The characteristics of myrmekite from the migmatites in Huoqiu District, western Anhui: Geological Review
(Dizhi Lunping), v. 26, no. 6, p. 499-504. (translation)

1990s

Augustithis, S. S., 1990. Atlas Of Metamorphic-Metasomatic Textures And Processes. Elsevier, Amsterdam, 228 pp.
Brodie, K. H., 1995, The development of oriented symplectites during deformation: Journal of Metamorphic Geology, v. 13,
no. 4, p. 499-508.
Collins, L. G., 1990, Cathodoluminescence microscopy of myrmekite: Comment. Geology, v. 18, p. 1163.
Collins, L. G., 1996, Metasomatic origin of the Cooma Complex in southeastern Australia: Theophrastus’ Contributions
to Advanced Studies in Geology, V. I, p. 105-112.
Collins, L. G., 1997a, Origin of myrmekite and metasomatic granite: Myrmekite, ISSN 1526-5757, electronic Internet
publication, no. 1, http://www.csun.edu/~vcgeo005/revised1.htm.
Collins, L. G., 1997b, Replacement of primary plagioclase by secondary K-feldspar and myrmekite: Myrmekite, ISSN
1526-5757, electronic Internet publication, no. 2, http://www.csun.edu/~vcgeo005/revised2.htm.
Collins, L. G., 1997c, Microscopic and megascopic relationships for myrmekite-bearing granitic rocks formed by
K-metasomatism: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 3, http://www.csun.edu/~vcgeo005/revised3.htm.
Collins, L. G., 1997d, Myrmekite formed by Ca-metasomatism: Myrmekite, ISSN 1526-5757, electronic Internet
publication, no. 4, http://www.csun.edu/~vcgeo005/revised4.htm.
Collins, L. G., 1997e, Myrmekite formed by exsolution?: Myrmekite, ISSN 1526-5757, electronic Internet publication,
no. 5, http://www.csun.edu/~vcgeo005/revised5.htm.
Collins, L. G., 1997f, Myrmekite as a clue to metasomatism on a plutonic scale; origin of some peraluminous granites:
Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 6, http://www.csun.edu/~vcgeo005/revised6.htm.
Collins, L. G., 1997g, K-differentiation in magmatic and metasomatic processes: Myrmekite, ISSN 1526-5757, electronic
Internet publication, no. 7, http://www.csun.edu/~vcgeo005/revised7.htm.
Collins, L. G., 1997h, Polonium halos and myrmekite in pegmatite and granite: Myrmekite, ISSN 1526-5757, electronic
Internet publication, no. 8, http://www.csun.edu/~vcgeo005/revised8.htm.
Collins, L. G., 1997i, Large-scale K- and Si-metasomatism to form the megacrystal quartz monzonite at Twentynine Palms,
California, USA: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 9, http://www.csun.edu/~vcgeo005/29palms.htm.
Collins, L. G., 1997j, K- and Si-metasomatism in the Donegal granites of northwest Ireland: Myrmekite, ISSN 1526-5757,
electronic Internet publication, no. 10, http://www.csun.edu/~vcgeo005/donegal.htm.
Collins, L. G., 1997k, Myrmekite in garnet-sillimanite-cordierite gneisses and Al-Ti-Zr trends, Gold Butte, Nevada:
Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 11, http://www.csun.edu/~vcgeo005/gold.htm.
Collins, L. G., 1997l, Myrmekite in the Santa Rosa mylonite zone, Palm Springs, California: Myrmekite, ISSN 1526-5757,
electronic Internet publication, no. 12, http://www.csun.edu/~vcgeo005/palm.htm.
Collins, L. G., 1997m, Myrmekite in the Rubidoux Mountain leucogranite – a replacement pluton: Myrmekite, ISSN
1526-5757, electronic Internet publication, no. 13, http://www.csun.edu/~vcgeo005/rubidoux.htm.
Collins, L. G., 1997n, Myrmekite in muscovite-garnet granites in the Mojave Desert, California, USA: Myrmekite,
ISSN 1526-5757, electronic Internet publication, no. 14, http://www.csun.edu/~vcgeo005/mojave.htm.
Collins, L. G., 1997o, Problems with the magmatic model for the origin of the Hall Canyon muscovite granite pluton,
Panamint Mountains, California, USA: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 15, http://www.csun.edu/~vcgeo005/hall.htm.
Collins, L. G., 1997p, Sericitization in the Skidoo pluton, California: A possible end-stage of large-scale
K-metasomatism: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 16, http://www.csun.edu/~vcgeo005/skidoo.htm.
Collins, L. G., 1997q, The mobility of iron, calcium, magnesium, and aluminum during K- and Si-metasomatism: Myrmekite,
ISSN 1526-5757, electronic Internet publication, no. 17, http://www.csun.edu/~vcgeo005/mobility.htm.
Collins, L. G., 1997r, Sphene, myrmekite, and titanium immobility and mobility; implications for large-scale
K- and Na-metasomatism and the origin of magnetite concentrations: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 18, http://www.csun.edu/~vcgeo005/sphene.htm.
Collins, L. G., 1997s, Contrasting characteristics of magmatic and metasomatic granites and the myth that granite plutons
can be only magmatic: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 19, http://www.csun.edu/~vcgeo005/myth.htm.
Collins, L. G., 1997t, Failure of the exsolution silica-pump model for the origin of myrmekite: Examination of
K-feldspar crystals in the Sharpners Pond tonalite, Massachusetts: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 20, http://www.csun.edu/~vcgeo005/pump.htm.
Collins, L. G., 1997u, Three challenging outcrops in the Marlboro Formation, Massachusetts, USA: Myrmekite, ISSN
1526-5757, electronic Internet publication, no. 21, http://www.csun.edu/~vcgeo005/three.htm.
Collins, L. G., 1997v, K-feldspar augen in the Ponaganset gneiss and Scituate granite gneiss, Rhode Island,
Connecticut, and Massachusetts, USA: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 22, http://www.csun.edu/~vcgeo005/augen.htm.
Collins, L. G., 1997w, A close scrutiny of the "Newer Granites" of the Caledonian Orogen in Scotland: Myrmekite,
ISSN 1526-5757, electronic Internet publication, no. 23, http://www.csun.edu/~vcgeo005/scotland.htm.
Collins, L. G., 1997x, Magmatic resorption versus subsolidus metasomatism – two different styles of K-feldspar replacement
of plagioclase: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 24, http://www.csun.edu/~vcgeo005/ajo.html.
Collins, L. G., 1997y, Muscovite-garnet granites in the Mojave Desert: Relation to crustal structure of the Cretaceous
arc: Comment: Geology, v. 25, p. 187.
Collins, L. G., 1998a, The microcline-orthoclase controversy – can microcline be primary?: Myrmekite, ISSN 1526-5757,
electronic Internet publication, no. 26, http://www.csun.edu/~vcgeo005/primary.htm.
Collins, L. G., 1998b, Metasomatic origin of the Cooma Complex in southeastern Australia: Myrmekite, ISSN 1526-5757,
electronic Internet publication, no. 27, http://www.csun.edu/~vcgeo005/cooma.htm.
Collins, L. G., 1998c, Primary microcline and myrmekite formed during progressive metamorphism and K-metasomatism
of the Popple Hill gneiss, Grenville Lowlands, northwest New York, USA: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 28, http://www.csun.edu/~vcgeo005/popple.htm.
Collins, L. G., 1998d, The K-replacement modifications of the Kavala megacrystal granodiorite and the Sithonia
euhedral-epidote-bearing, hornblende-biotite granodiorite in northern Greece: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 29, http://www.csun.edu/~vcgeo005/greece.htm.
Collins, L. G., 1998e, The K-replacement origin for the megacrystal Hermon-type granites in the Grenville Lowlands,
northwestern Adirondack Mountains, New York, USA: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 30, http://www.csun.edu/~vcgeo005/hermon.htm.
Collins, L. G., 1998f, The lateral secretion origin of Zn ores at Balmat and Edwards, New York, USA: Myrmekite, ISSN
1526-5757, electronic Internet publication, no. 31, http://www.csun.edu/~vcgeo005/zinc.htm.
Collins, L. G., 1998g, Exsolution vermicular perthite and myrmekitic mesoperthite: Myrmekite, ISSN 1526-5757,
electronic Internet publication, no. 32, http://www.csun.edu/~vcgeo005/perthite.htm.
Collins, L. G., 1998h, Origin of the augen granite gneiss in the Bill Williams Mountains, Arizona, USA: Myrmekite, ISSN
1526-5757, electronic Internet publication, no. 33, http://www.csun.edu/~vcgeo005/bill.htm.
Collins, L. G., 1998i, Metasomatic aluminous gneisses at Gold Butte, Nevada, U.S.A.; a clue to formation of strongly
peraluminous granites; in Theophrastus’ Contributions To Advanced Studies In Geology, Augustithis, S. S. and others (eds.), p. 33-46.
Collins, L. G., and Behnia, P.,1998, Petrogenesis of the Ghooshchi Granite by K- and Si-metasomatism of diorites and
gabbros, western Azerbaijan, Iran: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 25, http://www.csun.edu/~vcgeo005/iran.html.
Collins, L. G., 1999a, The K-replacement origin of the megacrystal lower Caribou Creek granodiorite and the Goat
Canyon-Halifax Creeks quartz monzonite – modifications of a former tonalite and diorite stock, British Columbia, Canada: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 34, http://www.csun.edu/~vcgeo005/caribou.htm.
Collins, L. G., 1999b, Experimental studies demonstrating metasomatic processes and their natural granitic environments:
Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 36, http://www.csun.edu/~vcgeo005/Orville.htm.
Collins, L. G., 1999c, Overlooked experimental evidence for K-replacements of plagioclase and origin of microcline in
granite plutons: Myrmekite, ISSN 1526-5757, electronic Internet publication, no. 37, http://www.csun.edu/~vcgeo005/Microcline.htm.
Garcia, D., Pascal, M., and Roux, J., 1996, Hydrothermal replacement of feldspars in igneous enclaves of the Velay
granite and the genesis of myrmekites: European Journal of Mineralogy, v. 8, no. 4, p. 703-717.
Hippertt, J. F., and Valarellie, J. V., 1998, Myrmekite constraints on the available models and a new hypothesis for its
formation: European Journal of Mineralogy, v. 10, nr. 2, p. 317-331.
Hopson, R. F., 1991, Morphology and origin of wartlike myrmekite: Geological Society of America Abstracts with Program,
v. 23, no. 2, p. 36.
Hopson, R. F., and Ramseyer, K., 1990a, Cathodoluminescence microscopy of myrmekite: Geology, v. 18, p. 336-339.
Hopson, R. F., and Ramseyer, K., 1990b, Cathodoluminescence microscopy of myrmekite: Reply: Geology, v. 18, p. 1163-
1164.
Hunt, C. W., Collins, L. G., and Skobelin, E. A., 1992: Expanding Geospheres, Polar Publishing, Calgary, Canada,
421 pp.
Jiashu, R., 1992, Origin of myrmekite: Acta Petrologica et Mineralogical (Yanshi Kuangwuxue Zazhi), v. 11, no. 4, p.
324-330. (translation)
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Acknowledgments

I thank my wife, Barbara, whose many excellent suggestions greatly improved this article. I also express my appreciation to David Liggett, who has helped me with the technical computer problems for getting this article and all the other articles on line for this electronic publication.

For more information contact Lorence Collins at: lorencec@sysmatrix.net 

Lorence G. Collins
Department of Geological Sciences
California State University Northridge
18111 Nordhoff Street
Northridge, California 91330-8266
FAX 818-677-2820