Pub Date : 2018-04-26DOI: 10.19080/OFOAJ.2018.07.555710
J. Schneider
At Carrizo Arroyo, southwest of Albuquerque, New Mexico, an approximately 100-m-thick section of the latest Pennsylvanian (latest Gzhelian) to Early Permian (early Asselian) Red Tanks Member of the Bursum Formation is exposed. This sedimentary succession is interpreted as a coastal plain on a very shallow shelf affected by repeated transgressions and regressions. Besides the marine marls and limestones, the most common lithotypes in the nonmarine fossiliferous intervals are greenish-gray and gray, variably sandy fine clastics. Lithology and facies architectures together document a low energy floodplain environment crossed by very shallow but wide flood channels. In the floodplain deposits, three basic taphotypes were observed: (1) the common plant bed type, (2) the rare conchostracan bed type, and (3) the insect bed type, which is not as rare as previously assumed. Plant beds are commonly formed by single layers of dm-long branches and leaves, as well as cm-sized plant fragments. Consequently, it is assumed that the Carrizo Arroyo plant beds were deposited by waning flood in shallow and wide floodplain channels. Conchostracan and insect beds have several features in common. Bedding planes with enrichments of conchostracans, freshwater pelecypods, insects, and, in places, eurypterids, contain tiny plant detritus of mmto cm-size only. They form a sub-mm to mm-thick layer only, and have a restricted lateral extent of several meters to decameters. Altogether, this points to autochthonous assemblages of aquatic arthropods and molluscs preserved in short-lived freshwater puddles and ponds on the floodplain. The common but generally isolated insect wings were most likely transported by winds and trapped at the water surface of those freshwater accumulations on the floodplain. Obviously, fossiliferous deposits at Carrizo Arroyo contain an assemblage of autochthonous and allochthonous elements of the insect fauna, covering environments from the hinterland down to the seacoast. This makes the Carrizo Arroyo Fossillagerstätte exceptional. 377
{"title":"Carrizo Arroyo, central New Mexico - a new late Palaeozoic taphotype of arthropod Fossillagerst�tte","authors":"J. Schneider","doi":"10.19080/OFOAJ.2018.07.555710","DOIUrl":"https://doi.org/10.19080/OFOAJ.2018.07.555710","url":null,"abstract":"At Carrizo Arroyo, southwest of Albuquerque, New Mexico, an approximately 100-m-thick section of the latest Pennsylvanian (latest Gzhelian) to Early Permian (early Asselian) Red Tanks Member of the Bursum Formation is exposed. This sedimentary succession is interpreted as a coastal plain on a very shallow shelf affected by repeated transgressions and regressions. Besides the marine marls and limestones, the most common lithotypes in the nonmarine fossiliferous intervals are greenish-gray and gray, variably sandy fine clastics. Lithology and facies architectures together document a low energy floodplain environment crossed by very shallow but wide flood channels. In the floodplain deposits, three basic taphotypes were observed: (1) the common plant bed type, (2) the rare conchostracan bed type, and (3) the insect bed type, which is not as rare as previously assumed. Plant beds are commonly formed by single layers of dm-long branches and leaves, as well as cm-sized plant fragments. Consequently, it is assumed that the Carrizo Arroyo plant beds were deposited by waning flood in shallow and wide floodplain channels. Conchostracan and insect beds have several features in common. Bedding planes with enrichments of conchostracans, freshwater pelecypods, insects, and, in places, eurypterids, contain tiny plant detritus of mmto cm-size only. They form a sub-mm to mm-thick layer only, and have a restricted lateral extent of several meters to decameters. Altogether, this points to autochthonous assemblages of aquatic arthropods and molluscs preserved in short-lived freshwater puddles and ponds on the floodplain. The common but generally isolated insect wings were most likely transported by winds and trapped at the water surface of those freshwater accumulations on the floodplain. Obviously, fossiliferous deposits at Carrizo Arroyo contain an assemblage of autochthonous and allochthonous elements of the insect fauna, covering environments from the hinterland down to the seacoast. This makes the Carrizo Arroyo Fossillagerstätte exceptional. 377","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132509465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Priewisch, L. Crossey, K. Karlstrom, H. Chafetz, M. Cook
The depositional facies and stable isotopic composition of a large-volume Quaternary travertine deposit located in the Rio Grande rift in New Mexico provide a record of the paleohydrology of springs along the western Rio Grande rift flank. Our results show that lateral and vertical facies variations within a travertine deposit developed due to changing depositional environments, which are primarily related to the formation of travertine mounds sourced by springs along the rift-bounding Comanche and Santa Fe faults. Important travertine facies are 1) a terraced mound and sloping fan facies that represents surface flow, and 2) a vein facies that reflects artesian waters within the developing mounds. Stable oxygen and carbon isotope analyses of the two facies show similar δ18O and δ13C values, ranging between -6.6‰ and -9.3‰, and +1.3‰ and +6.1‰, respectively. The range of δ18O values is similar to nearby springs along the west side of the rift and is interpreted to reflect variable mixing of endogenic (deeply derived) spring discharge with meteoric water. The δ13C values are significantly higher than values of nearby springs (δ13C = -1 to -8) and are interpreted to be controlled by variable CO2 degassing rates. The age and volume of the travertine deposit suggests that the mounds archive an estimated minimum of 54 Gigatons CO2 that degassed over a period of 456 ka along the fault system. Significant additional amounts of CO2 likely escaped to the atmosphere during travertine formation and δ13C fractionation. Travertine mound growth was facilitated by times of high CO2 flux and times of high groundwater head in confined aquifer systems. 405
{"title":"Geochronology and geochemical analysis of Quaternary travertine deposits at the Belen quarries of Mesa Aparejo, NM: Evaluation of travertine facies for paleohydrology and paleoenvironment Studies","authors":"A. Priewisch, L. Crossey, K. Karlstrom, H. Chafetz, M. Cook","doi":"10.56577/ffc-.405","DOIUrl":"https://doi.org/10.56577/ffc-.405","url":null,"abstract":"The depositional facies and stable isotopic composition of a large-volume Quaternary travertine deposit located in the Rio Grande rift in New Mexico provide a record of the paleohydrology of springs along the western Rio Grande rift flank. Our results show that lateral and vertical facies variations within a travertine deposit developed due to changing depositional environments, which are primarily related to the formation of travertine mounds sourced by springs along the rift-bounding Comanche and Santa Fe faults. Important travertine facies are 1) a terraced mound and sloping fan facies that represents surface flow, and 2) a vein facies that reflects artesian waters within the developing mounds. Stable oxygen and carbon isotope analyses of the two facies show similar δ18O and δ13C values, ranging between -6.6‰ and -9.3‰, and +1.3‰ and +6.1‰, respectively. The range of δ18O values is similar to nearby springs along the west side of the rift and is interpreted to reflect variable mixing of endogenic (deeply derived) spring discharge with meteoric water. The δ13C values are significantly higher than values of nearby springs (δ13C = -1 to -8) and are interpreted to be controlled by variable CO2 degassing rates. The age and volume of the travertine deposit suggests that the mounds archive an estimated minimum of 54 Gigatons CO2 that degassed over a period of 456 ka along the fault system. Significant additional amounts of CO2 likely escaped to the atmosphere during travertine formation and δ13C fractionation. Travertine mound growth was facilitated by times of high CO2 flux and times of high groundwater head in confined aquifer systems. 405","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125176949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Scholle, M. BouDagher-Fadel, D. Ulmer-Scholle, D. Love
A single half-meter-thick bed in the upper part of the Bursum Formation near Cibola Spring contains abundant carbonate nodules with distinctive knobby surface texture. These structures are shown to consist of the remains of a diverse assemblage of organisms, mainly foraminifers, which encrusted skeletal substrates and built finger-like columns with intervening uncolonized areas. The nodules are similar to previously described ones of comparable age from Kansas, Texas, southern New Mexico and other areas (variously termed “Osagia”, “Ottonosia”or “osagid grains”). However, they differ greatly from most “oncolites” or “algal biscuits” in lacking through-going laminations as well as lacking predominant macroscopic or microscopic algal contributors. The Bursum nodules are inferred to have formed in moderately deep waters (below normal wave base) in an open shelf setting. 369
{"title":"On the origin of carbonate nodules in the Bursum Formation at Cibola Spring, Socorro County, New Mexico","authors":"P. Scholle, M. BouDagher-Fadel, D. Ulmer-Scholle, D. Love","doi":"10.56577/ffc-.369","DOIUrl":"https://doi.org/10.56577/ffc-.369","url":null,"abstract":"A single half-meter-thick bed in the upper part of the Bursum Formation near Cibola Spring contains abundant carbonate nodules with distinctive knobby surface texture. These structures are shown to consist of the remains of a diverse assemblage of organisms, mainly foraminifers, which encrusted skeletal substrates and built finger-like columns with intervening uncolonized areas. The nodules are similar to previously described ones of comparable age from Kansas, Texas, southern New Mexico and other areas (variously termed “Osagia”, “Ottonosia”or “osagid grains”). However, they differ greatly from most “oncolites” or “algal biscuits” in lacking through-going laminations as well as lacking predominant macroscopic or microscopic algal contributors. The Bursum nodules are inferred to have formed in moderately deep waters (below normal wave base) in an open shelf setting. 369","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126149061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Koning, A. Jochems, G. Morgan, Virgil Lueth, L. Peters
Within 2 km northwest of downtown Truth or Consequences, the discovery of a fossil tooth identified as Neohipparion eurystyle and 40Ar/39Ar dating of cryptomelane in a fault zone indicate that a through-going, ancestral Rio Grande became established in the Engle and northern Palomas basins prior to 4.87 Ma (best estimate of 5.0 to 5.5? Ma). In the lower ~25 m of the ancestral Rio Grande deposits, referred to as the lower coarse unit (LCU), we differentiate three gravel-based petrofacies units. Gravel of the basal 3-5 m of the LCU in the southeastern part of the study area (petrofacies unit 1) consists almost entirely of Paleozoic and Mesozoic sedimentary rocks inferred to be derived from toe-cutting of the nearby Mescal-Ash Canyon paleofan during establishment of the ancestral Rio Grande. Gravel in the overlying petrofacies unit 2 is composed of felsic volcanic rocks plus minor Proterozoic clasts and Mesozoic-Paleozoic sedimentary clasts, reflecting mixing of gravel shed from highlands surrounding the Engle basin. Only petrofacies unit 3 contains notable exotic clasts transported by the ancestral Rio Grande, namely 10-40% quartzite and trace Pedernal chert, that are mixed with roughly subequal felsic and intermediate volcanic types shed from highlands located west-northwest of the study area. Stratigraphic relationships coupled with gravel transport paths indicate that early deposits of petrofacies 3, which contain a tooth of Neohipparion eurystyle and therefore predate 4.9 Ma, aggraded in a paleovalley inset into petrofacies 2. We interpret this paleovalley incision, as well as subsequent increased clast caliber and the first appearance of appreciable exotic clasts in petrofacies 3, to reflect an increase in Rio Grande stream power likely related to paleoclimate changes. 459 INTRODUCTION The Rio Grande is an integral feature of the economy, culture, and landscape of New Mexico and the American Southwest. It also serves as the axial river of the Rio Grande rift and flows through the 2016 NMGS Fall Field Conference area in Belen. The geomorphic history of this river relative to the rift has received much study (Denny, 1940; Ruhe, 1962; Kottlowski, 1953, 1958; Kottlowski et al., 1965; Bachman and Mehnert, 1978; Manley, 1979; Baldridge et al., 1980; Smith et al., 2001; Smith, 2004; Connell et al., 2005). One particularly intriguing event in the history of the Rio Grande rift and its namesake axial river was a remarkable downstream elongation of the Rio Grande from a playa-lake system in the southern Albuquerque and Socorro basins (possibly including the Belen area), where the Rio Grande terminated in the late Miocene, to playa-lakes in the El Paso area (Mack et al., 1997, 2006; Connell, 2004; Connell et al., 2005). This southward expansion resulted in the fluvial integration of several previously closed (endorheic) basins in south-central New Mexico, including the Engle, Palomas, Rincon-Hatch, and Mesilla basins. Previous studies have only partly co
在市中心西北2公里的范围内，发现了一颗被鉴定为新马帕龙eurystyle的牙齿化石，并在断裂带中发现了40Ar/39Ar的隐黑岩年龄，表明在4.87 Ma(最佳估计为5.0 ~ 5.5 Ma)之前，在恩格尔盆地和Palomas盆地北部建立了一个贯穿的，祖先的里约热内卢Grande。马)。在古里约热内卢大沉积下部~25 m处，划分出3个砾石基岩相单元，称为下粗单元(LCU)。研究区东南部LCU基底3 ~ 5 m的砾石(岩相单元1)几乎全部由古生代和中生代沉积岩组成，推断为在祖先里约热内卢Grande建立期间附近Mescal-Ash Canyon古扇的脚切割。上覆岩相单元2的砾石由长英质火山岩加少量元古代碎屑和中、古生界沉积碎屑组成，反映了恩格尔盆地周围高地砾石流的混合作用。只有岩相单元3含有明显的古里约热内卢Grande搬运的外来碎屑，即10-40%的石英岩和微量的腐斑燧石，它们与研究区西北偏西高地上的大致相当的长英质和中等火山类型混合在一起。地层关系和砾石输运路径表明，岩相3的早期沉积在嵌入岩相2的古山谷中沉积，其中含有新海马期eurystyle齿，沉积时间早于4.9 Ma。我们认为，这一古河谷切口，以及随后碎屑口径的增加和岩相3中首次出现明显的外来碎屑，反映了可能与古气候变化有关的里约热内卢大流功率的增加。里约热内卢Grande是新墨西哥州和美国西南部经济、文化和景观的一个组成部分。它也是里约热内卢大裂谷的轴向河流，流经2016年NMGS在贝伦的秋季野外会议区。这条河相对于裂谷的地貌历史已经得到了很多研究(Denny, 1940;孩子们,1962;Kottlowski, 1953,1958;Kottlowski et al.， 1965;巴赫曼和梅纳特，1978;Manley 1979;Baldridge et al.， 1980;Smith et al.， 2001;史密斯,2004;Connell et al.， 2005)。在里约热内卢Grande裂谷及其同名轴向河的历史中，一个特别有趣的事件是里约热内卢Grande从阿尔伯克基盆地南部和索科罗盆地(可能包括贝伦地区)的一个playa-lake系统(里约热内卢Grande终止于中新世晚期)向埃尔帕索地区的playa-lakes的显著下游延伸(Mack et al.， 1999,2006;康奈尔大学,2004;Connell et al.， 2005)。这种向南的扩张导致了新墨西哥州中南部几个先前封闭的(内陆)盆地的河流整合，包括恩格尔盆地、帕洛马斯盆地、林康-哈奇盆地和梅西拉盆地。以前的研究只是部分地限制了这种向南延伸的时间。在Socorro盆地西南部，地层关系结合火山岩的40Ar/39Ar测年表明，playa湖向贯穿轴流河的转变发生在6.88±0.02 Ma和3.73±0.1 Ma之间(分别为Chamberlin和Osburn(2006)和Chamberlin(1999)的Tbsh和Tbsc单元年龄);R.M.张伯伦，私人平民。, 2016)。几个独立的数据集证实，里约热内卢Grande形成于5.0 - 3.0 Ma之间的Engle、Palomas、Hatch-Rincon和Mesilla盆地。伴生盆地充填地层的年龄限制包括生物地层资料(Tedford, 1981;Repenning和May, 1986;Lucas and Oakes, 1986;Morgan和Lucas, 2003年，2011年，2012年;Morgan et al.， 2011)，玄武岩的K/ Ar定年(Bachman and Mehnert, 1978;Seager et al.， 1984)， Hatch Siphon浮石40Ar/39Ar定年及盆地内地球化学对比(3.12±0.03 Ma;Mack et al.， 1996,2009)和磁地层学(Mack et al.， 1993,1998,2006)。磁地层研究表明，帕洛玛斯盆地南部最早的里约热内卢Grande矿床年龄在4.997 ~ 4.631 Ma之间(即在Thvera和Nunivak亚时之间，年龄/ Ogg, 2012)。然而，恩格尔盆地和Palomas盆地北部最早的里约热内卢Grande矿床的年龄以前没有受到限制。本研究探索了在市中心西北2公里范围内最低暴露的里约热内卢大轴向矿床的地层、物源和年龄(图1)。在那里，峡谷和5至12米高(15至40英尺)的断崖的西向东排列显示，轴向河流矿床覆盖在明显更细、更红的矿床上发育的冲刷接触层上。研究区的初步地质图如图2所示。研究区域的一个有用的参考地点是BAR-2砂砾公司拥有的一个著名采石场，位于T或C市中心以西1公里处(图2)。 该研究结合正在进行的调查，有助于阐明祖先里约热内卢Grande到达Palomas盆地北部的时间和方式。Koning, Jochems, morgan, Lueth和Peters 460 Ti Tfp Tsf LPz Tsf Tb QTs
{"title":"Stratigraphy, gravel provenance, and age of early Rio Grande deposits exposed 1-2 km northwest of downtown Truth or Consequences, New Mexico","authors":"D. Koning, A. Jochems, G. Morgan, Virgil Lueth, L. Peters","doi":"10.56577/ffc-.459","DOIUrl":"https://doi.org/10.56577/ffc-.459","url":null,"abstract":"Within 2 km northwest of downtown Truth or Consequences, the discovery of a fossil tooth identified as Neohipparion eurystyle and 40Ar/39Ar dating of cryptomelane in a fault zone indicate that a through-going, ancestral Rio Grande became established in the Engle and northern Palomas basins prior to 4.87 Ma (best estimate of 5.0 to 5.5? Ma). In the lower ~25 m of the ancestral Rio Grande deposits, referred to as the lower coarse unit (LCU), we differentiate three gravel-based petrofacies units. Gravel of the basal 3-5 m of the LCU in the southeastern part of the study area (petrofacies unit 1) consists almost entirely of Paleozoic and Mesozoic sedimentary rocks inferred to be derived from toe-cutting of the nearby Mescal-Ash Canyon paleofan during establishment of the ancestral Rio Grande. Gravel in the overlying petrofacies unit 2 is composed of felsic volcanic rocks plus minor Proterozoic clasts and Mesozoic-Paleozoic sedimentary clasts, reflecting mixing of gravel shed from highlands surrounding the Engle basin. Only petrofacies unit 3 contains notable exotic clasts transported by the ancestral Rio Grande, namely 10-40% quartzite and trace Pedernal chert, that are mixed with roughly subequal felsic and intermediate volcanic types shed from highlands located west-northwest of the study area. Stratigraphic relationships coupled with gravel transport paths indicate that early deposits of petrofacies 3, which contain a tooth of Neohipparion eurystyle and therefore predate 4.9 Ma, aggraded in a paleovalley inset into petrofacies 2. We interpret this paleovalley incision, as well as subsequent increased clast caliber and the first appearance of appreciable exotic clasts in petrofacies 3, to reflect an increase in Rio Grande stream power likely related to paleoclimate changes. 459 INTRODUCTION The Rio Grande is an integral feature of the economy, culture, and landscape of New Mexico and the American Southwest. It also serves as the axial river of the Rio Grande rift and flows through the 2016 NMGS Fall Field Conference area in Belen. The geomorphic history of this river relative to the rift has received much study (Denny, 1940; Ruhe, 1962; Kottlowski, 1953, 1958; Kottlowski et al., 1965; Bachman and Mehnert, 1978; Manley, 1979; Baldridge et al., 1980; Smith et al., 2001; Smith, 2004; Connell et al., 2005). One particularly intriguing event in the history of the Rio Grande rift and its namesake axial river was a remarkable downstream elongation of the Rio Grande from a playa-lake system in the southern Albuquerque and Socorro basins (possibly including the Belen area), where the Rio Grande terminated in the late Miocene, to playa-lakes in the El Paso area (Mack et al., 1997, 2006; Connell, 2004; Connell et al., 2005). This southward expansion resulted in the fluvial integration of several previously closed (endorheic) basins in south-central New Mexico, including the Engle, Palomas, Rincon-Hatch, and Mesilla basins. Previous studies have only partly co","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132669299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Detrital zircon analysis has excellent potential to elucidate the evolution of the Rio Grande‒Rio Chama fluvial system by characterizing the provenance of sediment and assessing fluvial connectivity of Rio Grande rift basins through time. This study uses U-Pb geochronology of detrital zircon separated from modern river sediment, terrace deposits with the Lava Creek B ash (640 ka), and three intermediate terraces to reconstruct the provenance of sediment carried by the Rio Grande‒Rio Chama fluvial system over the last 640 ka. U-Pb detrital zircon ages for Red River sediment are further supported by high precision 40Ar/39Ar detrital sanidine dating, which has the ability to identify age populations that are not resolved by lower precision detrital zircon dates. The detrital zircon age spectra of a 640 ka Rio Grande terrace in the Albuquerque Basin and a 640 ka Rio Chama terrace show a number of diagnostic age peaks: 1) 23-25 Ma characteristic of the Latir Volcanic Field, 2) 27-28 Ma that could be either from the Latir or San Juan Volcanic Fields, 3) 34-35 Ma characteristic of the San Juan Volcanic Field, 4) Cretaceous-aged peaks, and 5) a “triple peak” consisting of 1.7, 1.4, and 1.1 Ga zircon derived from Precambrian basement, which is common in Phanerozoic sediments throughout the western U.S. Based on two samples, we interpret relatively abundant 28-36 Ma zircon in river sediment to be characteristic of the Rio Chama. These similarities are compatible with models showing that the Rio Chama – with San Juan Mountain headwaters – dominated the river system at 640 ka. Similar 28-35 Ma zircon in a 250˗350 ka Rio Grande terrace in the Española Basin is compatible with models positing a San Juan Mountain source of detritus for the Rio Grande after spillover of Lake Alamosa ~430 ka, and with reworking of Santa Fe Group sediment. The 27-28 Ma temporal overlap between the San Juan and Latir Volcanic Fields is problematic for provenance, but modern river sand samples suggest it is possible to distinguish the 28 Ma San Juan Volcanic Field (Fish Canyon Tuff) zircon peak from the 22-27 Ma Latir Volcanic Field zircon peak. Although the Latir Volcanic Field has a 28.2 Ma tuff (Tetilla Peak Tuff), its associated zircon is much less abundant than younger zircon (e.g., the 25.49 Ma Amalia Tuff). The similar pattern of age peaks between 640 ka fluvial sediment in the Albuquerque Basin and the Rio Chama indicates that the Rio Chama dominated the river system at 640 ka. Preliminary detrital sanidine data for Red River sediment that was derived from the Latir Volcanic Field show that 23-25 Ma sanidine is twice as abundant as 27-29 Ma sanidine, and therefore abundant 27-29 Ma zircon in the Rio Grande system is interpreted to indicate fluvial connectivity to the San Juan Mountains. 479
{"title":"New insights on the late Pleistocene Rio Grande-Rio Chama fluvial system from detrital zircon dating","authors":"M. Repasch, K. Karlstrom, M. Heizler, D. Koning","doi":"10.56577/ffc-.479","DOIUrl":"https://doi.org/10.56577/ffc-.479","url":null,"abstract":"Detrital zircon analysis has excellent potential to elucidate the evolution of the Rio Grande‒Rio Chama fluvial system by characterizing the provenance of sediment and assessing fluvial connectivity of Rio Grande rift basins through time. This study uses U-Pb geochronology of detrital zircon separated from modern river sediment, terrace deposits with the Lava Creek B ash (640 ka), and three intermediate terraces to reconstruct the provenance of sediment carried by the Rio Grande‒Rio Chama fluvial system over the last 640 ka. U-Pb detrital zircon ages for Red River sediment are further supported by high precision 40Ar/39Ar detrital sanidine dating, which has the ability to identify age populations that are not resolved by lower precision detrital zircon dates. The detrital zircon age spectra of a 640 ka Rio Grande terrace in the Albuquerque Basin and a 640 ka Rio Chama terrace show a number of diagnostic age peaks: 1) 23-25 Ma characteristic of the Latir Volcanic Field, 2) 27-28 Ma that could be either from the Latir or San Juan Volcanic Fields, 3) 34-35 Ma characteristic of the San Juan Volcanic Field, 4) Cretaceous-aged peaks, and 5) a “triple peak” consisting of 1.7, 1.4, and 1.1 Ga zircon derived from Precambrian basement, which is common in Phanerozoic sediments throughout the western U.S. Based on two samples, we interpret relatively abundant 28-36 Ma zircon in river sediment to be characteristic of the Rio Chama. These similarities are compatible with models showing that the Rio Chama – with San Juan Mountain headwaters – dominated the river system at 640 ka. Similar 28-35 Ma zircon in a 250˗350 ka Rio Grande terrace in the Española Basin is compatible with models positing a San Juan Mountain source of detritus for the Rio Grande after spillover of Lake Alamosa ~430 ka, and with reworking of Santa Fe Group sediment. The 27-28 Ma temporal overlap between the San Juan and Latir Volcanic Fields is problematic for provenance, but modern river sand samples suggest it is possible to distinguish the 28 Ma San Juan Volcanic Field (Fish Canyon Tuff) zircon peak from the 22-27 Ma Latir Volcanic Field zircon peak. Although the Latir Volcanic Field has a 28.2 Ma tuff (Tetilla Peak Tuff), its associated zircon is much less abundant than younger zircon (e.g., the 25.49 Ma Amalia Tuff). The similar pattern of age peaks between 640 ka fluvial sediment in the Albuquerque Basin and the Rio Chama indicates that the Rio Chama dominated the river system at 640 ka. Preliminary detrital sanidine data for Red River sediment that was derived from the Latir Volcanic Field show that 23-25 Ma sanidine is twice as abundant as 27-29 Ma sanidine, and therefore abundant 27-29 Ma zircon in the Rio Grande system is interpreted to indicate fluvial connectivity to the San Juan Mountains. 479","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"48 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132686337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biostratigraphic importance of the small, isolated exposure of the upper Cretaceous Dakota sandstone at Canyon View, Palo Duro Canyon, Sevilleta Nationional Wildlife Refuge, New Mexico","authors":"S. Hook","doi":"10.56577/ffc-.31","DOIUrl":"https://doi.org/10.56577/ffc-.31","url":null,"abstract":"","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"528 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116219227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Triassic-Jurassic stratigraphy on the Becker SW quadrangle and vicinity, Socorro County, New Mexico","authors":"S. Lucas, B. Allen, D. Love","doi":"10.56577/ffc-.27","DOIUrl":"https://doi.org/10.56577/ffc-.27","url":null,"abstract":"","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122756904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Grants obsidian in the Ceja formation beneath the Llano de Albuquerque south of Belen","authors":"J. D. Young, D. Love","doi":"10.56577/ffc-.22","DOIUrl":"https://doi.org/10.56577/ffc-.22","url":null,"abstract":"","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115195820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Grambling, K. Karlstrom, M. Holland, N. Grambling
A bstrAct — The Sandia-Manzano and adjacent Los Piños mountains, the eastern uplift of the Rio Grande rift along the Albuquerque basin, expose a series of Paleoproterozoic and Mesoproterozoic plutons that intrude the 1.70-1.60 Ga Manzano Group within the Manzano thrust belt. This paper summarizes the age and tectonic setting of two distinct pulses of magmatism: one at 1.67-1.64 Ga and one at 1.46-1.45 Ga. The 1.67-1.64 Ga granite plutons are as follows, from north to south, the 1669±13 Ma Monte Largo Hills, 1653±16 Ma Cibola, 1655±14 Ma Manzanita, 1659±5 Ma Ojito, and 1655±1 Ma Los Piños/Sepultura granites. Circa 1.45 Ga magmatism is recorded in the 1453±12 Ma Sandia Pluton, and the 1456±13 Ma Priest Pluton. The plutons range from monzogranite to granodiorite. The older plutonic suite is closely associated with a period of voluminous bimodal rhyolite-basalt volcanism. The temporal, spatial, and chemical proximity of these volcanics to the 1.65 Ga plutons suggests a tectonic relationship between intrusive and extrusive products of the same magmatic system. This relationship is explained in terms of rhyolitic, caldera-style eruptions that were intruded by plutons of similar age. Metamorphic assemblages and fabrics in aureoles of both the 1.65 Ga and 1.46 Ga plutons indicate syntectonic (syncontractional) emplacement at middle crustal depths of 3-4 km. Contact aureoles of 1.65 plutons have andalusite-sillimanite assemblages, and those of 1.46 plutons have triple point aluminosilicate assemblages (550°C, 3.5 kbars). The 1.45-1.46 Ga suite has no known proximal extrusive activity and is associated with late-stage aplite and pegmatite dikes, which frequently crosscut the outer margins of the plutons. Extrusive equivalents may be present east of the Rocky Moun- tain front in the western Granite-Rhyolite provinces. The plutons and their aureoles record two episodes of deformation and metamorphism: the 1.65 Ga Mazatzal orogeny, and the 1.45 Ga Picuris orogeny. Collectively, these two events produced the observed polyphase strain fabric in the Manzano Group rocks of the Manzano Mountains.
摘要/ abstract摘要:位于阿尔布开克盆地里约热内卢大裂谷东隆起的Sandia-Manzano及其邻近的Los Piños山脉，暴露出一系列侵入曼萨诺冲断带1.70-1.60 Ga曼萨诺群的古元古代和中元古代岩体。本文总结了1.67 ~ 1.64 Ga和1.46 ~ 1.45 Ga两个不同的岩浆活动脉冲的年龄和构造背景。1.67 ~ 1.64 Ga花岗岩岩体由北向南依次为1669±13 Ma Monte Largo Hills、1653±16 Ma Cibola、1655±14 Ma Manzanita、1659±5 Ma Ojito和1655±1 Ma Los Piños/Sepultura花岗岩。1453±12 Ma的桑迪亚岩体和1456±13 Ma的普雷斯特岩体记录了1.45 Ga左右的岩浆活动。岩体范围从二长花岗岩到花岗闪长岩。较老的深成岩套与大量的双峰流纹岩-玄武岩火山作用期密切相关。这些火山在时间、空间和化学上与1.65 Ga的岩体接近，表明同一岩浆系统的侵入产物和喷出产物之间存在构造关系。这种关系可以用流纹岩、破火山口式喷发来解释，这些喷发被类似年龄的岩体侵入。1.65 Ga和1.46 Ga岩体的光晕中的变质组合和构造表明在地壳中深度3 ~ 4 km处有同构造(同收缩)侵位。1.65岩体的接触光晕具有红柱石-硅线石组合，1.46岩体的接触光晕具有三点铝硅酸盐组合(550℃，3.5 kbar)。1.45-1.46 Ga组没有已知的近端挤压活动，与晚期的长晶岩和伟晶岩岩脉有关，这些岩脉经常横切岩体的外缘。在西部花岗岩流纹岩省的落基山前缘以东可能有类似的挤出物。岩体及其光环记录了1.65 Ga马扎扎尔造山运动和1.45 Ga Picuris造山运动两期变形变质作用。总的来说，这两个事件在曼萨诺山脉的曼萨诺群岩石中产生了观察到的多相应变结构。
{"title":"Proterozoic magmatism and regional contact metamorphism in the Sandia-Manzano Mountains, New Mexico, USA","authors":"T. Grambling, K. Karlstrom, M. Holland, N. Grambling","doi":"10.56577/ffc-.169","DOIUrl":"https://doi.org/10.56577/ffc-.169","url":null,"abstract":"A bstrAct — The Sandia-Manzano and adjacent Los Piños mountains, the eastern uplift of the Rio Grande rift along the Albuquerque basin, expose a series of Paleoproterozoic and Mesoproterozoic plutons that intrude the 1.70-1.60 Ga Manzano Group within the Manzano thrust belt. This paper summarizes the age and tectonic setting of two distinct pulses of magmatism: one at 1.67-1.64 Ga and one at 1.46-1.45 Ga. The 1.67-1.64 Ga granite plutons are as follows, from north to south, the 1669±13 Ma Monte Largo Hills, 1653±16 Ma Cibola, 1655±14 Ma Manzanita, 1659±5 Ma Ojito, and 1655±1 Ma Los Piños/Sepultura granites. Circa 1.45 Ga magmatism is recorded in the 1453±12 Ma Sandia Pluton, and the 1456±13 Ma Priest Pluton. The plutons range from monzogranite to granodiorite. The older plutonic suite is closely associated with a period of voluminous bimodal rhyolite-basalt volcanism. The temporal, spatial, and chemical proximity of these volcanics to the 1.65 Ga plutons suggests a tectonic relationship between intrusive and extrusive products of the same magmatic system. This relationship is explained in terms of rhyolitic, caldera-style eruptions that were intruded by plutons of similar age. Metamorphic assemblages and fabrics in aureoles of both the 1.65 Ga and 1.46 Ga plutons indicate syntectonic (syncontractional) emplacement at middle crustal depths of 3-4 km. Contact aureoles of 1.65 plutons have andalusite-sillimanite assemblages, and those of 1.46 plutons have triple point aluminosilicate assemblages (550°C, 3.5 kbars). The 1.45-1.46 Ga suite has no known proximal extrusive activity and is associated with late-stage aplite and pegmatite dikes, which frequently crosscut the outer margins of the plutons. Extrusive equivalents may be present east of the Rocky Moun- tain front in the western Granite-Rhyolite provinces. The plutons and their aureoles record two episodes of deformation and metamorphism: the 1.65 Ga Mazatzal orogeny, and the 1.45 Ga Picuris orogeny. Collectively, these two events produced the observed polyphase strain fabric in the Manzano Group rocks of the Manzano Mountains.","PeriodicalId":243410,"journal":{"name":"Guidebook 67 - Geology of the Belen Area","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115329966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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