{"title":"山谷-托莱多火山口复合体的流纹岩和伴生矿床","authors":"J. Gardner, F. Goff, S. Kelley, E. Jacobs","doi":"10.58799/nmg-v32n1.3","DOIUrl":null,"url":null,"abstract":"Several decades of focused studies on the Valles–Toledo caldera complex and the Jemez Mountains in northern New Mexico have brought about new understanding of the relations of stratigraphic units that record the complex’s evolution. We present here a revision of the formal stratigraphic nomenclature for the Quaternary Tewa Group, an established stratigraphic unit that includes the volcanic and volcaniclastic deposits of the caldera complex. We propose 11 completely new units of member rank, with descriptions of lithology, contact relations, distribution, and type areas. These new members are parts of the Bandelier Tuff, Cerro Toledo, and Valles Rhyolite Formations, and serve to depict the magmatic and geomorphic evolution of the area during and following each of two major caldera-forming episodes. With results from mapping efforts in the Jemez Mountains revealing the broad implications and interrelations of some established units, we redefine one formation (Cerro Toledo Rhyolite) and demote three formal members (El Cajete, Battleship Rock, and Banco Bonito) to bed or flow rank. Because it has been shown repeatedly in published works that one formation (Cerro Rubio Quartz Latite) was originally defined based on erroneous relations, we propose its formal abandonment. Additionally, we propose formal abandonment of one established member (Valle Grande Member of the Valles Rhyolite) because of lack of utility and widespread disuse. Our proposed revisions embody the practices of geologic mappers, and serve to better clarify relations of volcanic and volcaniclastic rocks through the evolution of the Valles–Toledo caldera complex. The new formal stratigraphy that we propose will provide a flexible but robust framework for on-going and future research in the Valles–Toledo caldera complex.","PeriodicalId":35824,"journal":{"name":"New Mexico Geology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"24","resultStr":"{\"title\":\"Rhyolites and associated deposits of the Valles - Toledo caldera complex\",\"authors\":\"J. Gardner, F. Goff, S. Kelley, E. Jacobs\",\"doi\":\"10.58799/nmg-v32n1.3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Several decades of focused studies on the Valles–Toledo caldera complex and the Jemez Mountains in northern New Mexico have brought about new understanding of the relations of stratigraphic units that record the complex’s evolution. We present here a revision of the formal stratigraphic nomenclature for the Quaternary Tewa Group, an established stratigraphic unit that includes the volcanic and volcaniclastic deposits of the caldera complex. We propose 11 completely new units of member rank, with descriptions of lithology, contact relations, distribution, and type areas. These new members are parts of the Bandelier Tuff, Cerro Toledo, and Valles Rhyolite Formations, and serve to depict the magmatic and geomorphic evolution of the area during and following each of two major caldera-forming episodes. With results from mapping efforts in the Jemez Mountains revealing the broad implications and interrelations of some established units, we redefine one formation (Cerro Toledo Rhyolite) and demote three formal members (El Cajete, Battleship Rock, and Banco Bonito) to bed or flow rank. Because it has been shown repeatedly in published works that one formation (Cerro Rubio Quartz Latite) was originally defined based on erroneous relations, we propose its formal abandonment. Additionally, we propose formal abandonment of one established member (Valle Grande Member of the Valles Rhyolite) because of lack of utility and widespread disuse. Our proposed revisions embody the practices of geologic mappers, and serve to better clarify relations of volcanic and volcaniclastic rocks through the evolution of the Valles–Toledo caldera complex. The new formal stratigraphy that we propose will provide a flexible but robust framework for on-going and future research in the Valles–Toledo caldera complex.\",\"PeriodicalId\":35824,\"journal\":{\"name\":\"New Mexico Geology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2010-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"24\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"New Mexico Geology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.58799/nmg-v32n1.3\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Earth and Planetary Sciences\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Mexico Geology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.58799/nmg-v32n1.3","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
Rhyolites and associated deposits of the Valles - Toledo caldera complex
Several decades of focused studies on the Valles–Toledo caldera complex and the Jemez Mountains in northern New Mexico have brought about new understanding of the relations of stratigraphic units that record the complex’s evolution. We present here a revision of the formal stratigraphic nomenclature for the Quaternary Tewa Group, an established stratigraphic unit that includes the volcanic and volcaniclastic deposits of the caldera complex. We propose 11 completely new units of member rank, with descriptions of lithology, contact relations, distribution, and type areas. These new members are parts of the Bandelier Tuff, Cerro Toledo, and Valles Rhyolite Formations, and serve to depict the magmatic and geomorphic evolution of the area during and following each of two major caldera-forming episodes. With results from mapping efforts in the Jemez Mountains revealing the broad implications and interrelations of some established units, we redefine one formation (Cerro Toledo Rhyolite) and demote three formal members (El Cajete, Battleship Rock, and Banco Bonito) to bed or flow rank. Because it has been shown repeatedly in published works that one formation (Cerro Rubio Quartz Latite) was originally defined based on erroneous relations, we propose its formal abandonment. Additionally, we propose formal abandonment of one established member (Valle Grande Member of the Valles Rhyolite) because of lack of utility and widespread disuse. Our proposed revisions embody the practices of geologic mappers, and serve to better clarify relations of volcanic and volcaniclastic rocks through the evolution of the Valles–Toledo caldera complex. The new formal stratigraphy that we propose will provide a flexible but robust framework for on-going and future research in the Valles–Toledo caldera complex.
期刊介绍:
New Mexico Geology is a quarterly, peer-reviewed journal available by subscription. Articles of original research are generally less than 10,000 words in length and pertain to the geology of New Mexico and neighboring states, primarily for an audience of professional geologists or those with an interest in the geologic story behind the landscape. The journal also publishes abstracts from regional meetings, theses, and dissertations (NM schools), descriptions of new publications, book reviews, and upcoming meetings. Research papers, short articles, and abstracts from selected back issues of New Mexico Geology are now available as free downloads in PDF format. Back issues are also available in hard copy for a nominal fee.