Geology of the Taos Region最新文献

{"title":"Gravity and aeromagnetic expression of tectonic and volcanic elements of the southern San Luis Basin, New Mexico and Colorado","authors":"V. Grauch, G. Keller","doi":"10.56577/ffc-55.230","DOIUrl":"https://doi.org/10.56577/ffc-55.230","url":null,"abstract":"A BSTRACT .—The San Luis Basin has been characterized as an east-tilted, northerly trending rift basin containing a narrow deep graben on the east and a largely buried, intrarift basement horst on the west. We refine these concepts for the southern San Luis Basin by revisiting existing gravity and aeromagnetic data using modern methods. In the New Mexico portion of the basin, the narrow (6-12 km) Taos graben follows a general north-south trend from Costilla near the state line to the Embudo fault at the southern end of the basin. West of the Taos graben, the intrarift basement horst changes orientation from north-south in Colo- rado to southwestward south of the state line, merging with the Tusas Mountains in a complicated manner that is not entirely understood. At the state line, the Taos graben widens northward to reach 25-30 km wide in the Culebra reentrant in Colorado, accompanied by en echelon stepping of the western graben border to the west. For nearly the entire length of the graben, the gravity-defined western border coincides with Quaternary faults and is followed or paralleled by the course of the Rio Grande. In the southernmost basin, the intrarift horst is absent. Instead, a broad semi-circular gravity low (Tres Orejas gravity low) of ambiguous origin lies west of the geophysically defined Taos graben. Along the southern border of the San Luis Basin, a strong gravity gradient follows the Embudo fault farther westward than previously proposed for a scissors fault configuration. South of the Embudo fault, north-south gradients in both gravity and aeromagnetic data correspond to the Picuris-Pecos fault system and suggest a related, parallel fault exists about 20 km to the west. Prominent circular aeromagnetic anomalies in the Taos Plateau can be associated with individual volcanoes and are used to infer the remanent magnetic polarities the rocks acquired when they cooled. A circular aeromagnetic anomaly near the Gorge bridge suggests a previously unknown volcano lies beneath the Servilleta Basalt. This information can be used to aid future geologic mapping of the Plateau and, in certain circumstances, can help constrain uncertain or multiple age dates for the volcanoes.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122273150","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":"The Flanks of the Rift - Second-day Road Log from Taos of Taos Pueblo, Llano Quemado, Pilar and Return to Taos","authors":"P. Bauer, A. Read, K. Kelson, W. Muehlberger, D. Koning","doi":"10.56577/ffc-55.37","DOIUrl":"https://doi.org/10.56577/ffc-55.37","url":null,"abstract":"Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"24 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":"124926320","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":"Sedimentology of the Tesuque Formation and tectonics of the Embudo fault system Near Dixon, New Mexico","authors":"S. Aby, D. Koning","doi":"10.56577/ffc-55.351","DOIUrl":"https://doi.org/10.56577/ffc-55.351","url":null,"abstract":"A BSTRACT . —The northeastern part of the Velarde 7.5-minute quadrangle, in the Dixon area, is underlain by Tertiary strata of the Tesuque Formation and an isolated outcrop of Proterozoic metasedimentary rocks of the Hondo and/or Vadito Groups. Faults associated with the transfer zone between the San Luis and Española Basins of the Rio Grande rift traverse the map area from southwest to northeast. We use the term Embudo fault system to refer to this zone of deformation and have assigned informal names to individual faults and fault zones within this system. In this area, the Embudo fault system is a ~5-km-wide zone of normal, oblique-normal, and local reverse faults. The Chama-El Rito Member (~12.5-17.5 Ma), the informally defined (Steinpress, 1980) Dixon member (~11.8-13 Ma), the Ojo Caliente Sandstone Member (~11.5-13 Ma), and the Cejita Member (~7.5-10 Ma) of the a combination of on fossil and regional stratigraphic relations. provi- mixed eolian, fluvially-reworked eolian and fluvial deposits lying above Caliente Sandtone Member of Leininger (1982). landslides on Proterozoic-Pliocene units are offset along numerous faults within the Embudo fault system. is mostly normal left-lateral and dominantly down–to-the-northwest although outcrop patterns suggest a complex history of deformation including tilting, extension, localized(?) compression, and shear. Compression in this area is most likely related to a restraining bend in the southeastern margin of the fault system. Tertiary unit contacts are laterally offset between and 2.75 km within and across a zone of intense deformation ~.5 km wide that makes up the southeastern margin of the fault system. Vertical-offset measurements within/across this zone cannot be made with confidence due to interfingering relations between Tertiary units and the complications arising from left-lateral offset. Pliocene basalt are offset 60-70 m vertically and pos- sibly up 460 m laterally across the La Mesita fault. Tertiary units generally dip toward the southwest. This tilting preceded offset within the Embudo fault system and much it between deposition the Ojo members of the Cejita Member, although some","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"148 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":"122925757","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":"Geologic structure of the Velarde Graben and the southern Embudo fault system, north-central New Mexico","authors":"D. Koning, J. Ferguson, P. Paul, W. S. Baldridge","doi":"10.56577/ffc-55.158","DOIUrl":"https://doi.org/10.56577/ffc-55.158","url":null,"abstract":"A BSTRACT .—The northeast-trending Embudo fault has a significant component of left-lateral slip and acts as a transfer fault in relaying extensional strain between the San Luis and Española Basins. In the northern Española Basin, the Embudo fault system links with the La Mesita and Dixon-Velarde faults of the northern Velarde graben, a 6-10 km-wide intra-rift graben. There is no evidence that a single scissors fault connects the down-to-the-northwest Embudo fault with the major down-to-the-east faults that bound the western side of the deepest parts of the central Española Basin (e.g., the Pajarito fault system). Rather, late Cenozoic slip associated with the Embudo fault appears to be partitioned amongst several major faults in the Velarde graben. In the southern Velarde graben, a lateral transfer of slip likely occurs between these faults and a major down-to-the-east fault called the Santa Clara fault. This transfer zone likely corresponds to an important fault segment boundary and is marked by transverse folds that may follow a transverse basement structure. Stratigraphic and seismic data indicate that substantial throw occurred along at least two major Velarde graben faults prior to the deposition of upper Miocene strata. This interpretation is consistent with a steepening of seismic reflectors with depth along the eastern margin of the Velarde graben. We speculate that the gravity high extending northwestward from the Picuris Mountains may correspond to a structural high related to the early development of the rift transfer zone between the Española and San Luis Basins. Subsequently, fault propagation and linkage may have formed a through-going Embudo fault system.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"38 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131894760","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":"Taos regional groundwater flow model","authors":"P. Burck, P. Barroll, A. Coré, D. Rappuhn","doi":"10.56577/ffc-55.433","DOIUrl":"https://doi.org/10.56577/ffc-55.433","url":null,"abstract":"A BSTRACT .— The Mexico Office of the State Engineer Hydrology Bureau has developed a regional, 7-layer, groundwa- ter flow model of the Taos Valley, New Mexico using MODFLOW-2000. This model was designed and developed together with the Taos Technical Committee, a team of experts in hydrology and geology, with many years of experience in the Taos area, and in conjunction with a U. S. Bureau of Reclamation (BOR) surface water model. Results from recent hydrogeologic investigations are incorporated, including deep drilling and hydrologic testing sponsored by the BOR, and the latest geologic mapping by the New Mexico Bureau of Geology and Mineral Resources. The model simulates groundwater flow in about 3000 ft of alluvial and volcanic materials, and is designed to estimate aquifer drawdowns and depletion effects to the Rio Grande, its tributaries and springs. The groundwater model serves two primary functions: first, as a tool to administer water rights, and second, to evaluate scenarios in settlement negotiations in an on-going water rights adjudication. This model simulates key hydrologic processes including natural recharge, irrigation seepage, evapotranspiration, and aquifer interaction with the Rio Grande and its tributaries and Buffalo Pasture Springs. Geologic strata represented in the model include Quaternary alluvial fan deposits, Tertiary Servilleta Basalt flows, and Tertiary Santa Fe Group sediments. The model simulates heads and groundwater discharges reasonably well, and captures major groundwater features such as large downward vertical gradients, thus allowing the interaction of the shallow and deep aquifer systems to be well simulated.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"69 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":"132918765","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":"The Taos Plateau and the Rio Grande Gorge - First-day road log from Taos to Questa, the Wild Rivers Recreation Area, Arroyo Hondo, the Dunn Bridge, the Rio Grande Gorge Bridge, and return to Taos","authors":"A. Read, P. Bauer, Ren A. Thompson, K. Kelson, W. Muehlberger","doi":"10.56577/ffc-55.1","DOIUrl":"https://doi.org/10.56577/ffc-55.1","url":null,"abstract":"The investigation uses a multi-faceted approach to determining pre-mining ground water quality, including determination of the existing hydrogeologic and geochemical conditions at off-site analog areas, modeling of the hydrogeochemical conditions off site, determining parameters that would have affected on-site controls of hydrogeology and geochemistry before mining, and appropriate scaling and modeling of on-site conditions.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"41 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":"117263315","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":"Preliminary interpretation of high-resolution aeromagnetic data collected near Taos, New Mexico","authors":"V. Grauch, P. Bauer, K. Kelson","doi":"10.56577/ffc-55.244","DOIUrl":"https://doi.org/10.56577/ffc-55.244","url":null,"abstract":"A BSTRACT . —High-resolution aeromagnetic data were recently collected in an area surrounding the Town of Taos to improve the regional geologic understanding of the subsurface. Qualitative and quantitative analyses of the data were integrated to obtain a preliminary interpretation. The primary sources of aeromagnetic anomalies are interpreted as Servilleta Basalt with dominantly reversed-polarity remanent magnetization, weakly to moderately magnetic Precambrian crystalline basement, and magnetic Tertiary intrusions. In the western part of the survey area, we interpret an area of shallow Servilleta Basalt cut by north-striking faults, which are related to the Los Cordovas faults. The area of shallow basalt is faulted down to the east on the eastern side, and is truncated by northeast-striking faults near the Rio Pueblo de Taos on the southern side. A basement struc- tural bench under the Town of Taos, which appears to be bounded by some of the northeast-striking faults, likely continues into a structurally complex area underlying the Buffalo Pasture area, but the configuration is unclear. In the northeastern part of the survey area, we interpret rift-related and pre-rift faults that strike north and northwest, respectively. The north-striking faults align with the Rio Lucero, supporting the premise that the drainage is tectonically controlled. Faults of both orientations appear to bound basement structural benches that step down to the south and west. In the southern and east-central parts of the area, aeromagnetically inferred faults parallel major variations in orientation of the Embudo, Sangre de Cristo and Picuris-Pecos fault systems. The parallel faults occur within a 2- to 7-km-wide zone from the range front into the basin. We interpret high-amplitude aeromagnetic anomalies along the northern and northeastern survey perimeters to represent Tertiary plutons, which are partially exposed and intrude Precambrian rocks in the north.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"95 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":"124854636","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":"Structural and stratigraphic development of the Miranda Graben constrains the uplift of the Picuris Mountains","authors":"D. W. McDonald, K. C. Nielsen","doi":"10.56577/ffc-55.219","DOIUrl":"https://doi.org/10.56577/ffc-55.219","url":null,"abstract":"A BSTRACT .—The Miranda graben is a complex extension zone located at the junction of the N-striking Picuris-Pecos fault (PPF) and the ENE-striking Embudo fault in the Sangre de Cristo Mountains of northern New Mexico. The PPF is reactivated and segmented into at least 3 segments by the ENE-striking Embudo fault and by several Laramide age NW-striking tear faults. These segments are (from N to S): the Taos, the Picuris, and the Pecos segments. On the east side of the Picuris segment in the Picuris Mountains, the Oligocene-Miocene Miranda graben is formed by the N-striking La Serna fault on the west, the NNE- striking Miranda fault on the east, and the ENE-striking Embudo fault to the north. In the Oligocene, the lower member of the Picuris Formation was deposited east of the PPF. The Bradley conglomerate member was deposited in the north-central Picuris Mountains and is (interpreted to be) laterally equivalent to the lower member. The Proterozoic Ortega Quartzite Formation in the northern Picuris Mountains is inferred to be the main source for these conglomerates, which suggests that the west side of the PPF remained uplifted or was rejuvenated at the end of the late Laramide deformation. By late Oligocene time, subsidence within the graben had begun, as evidenced by the limited deposits of the Llano Quemado breccia. Following deposition of the breccia increased subsidence produced an angular unconformity between the steeply W-dipping breccia and the overlying almost horizontal upper member of the Picuris Formation. In the last 10 m.y. subsidence in the San Luis and Española Basins caused the Picuris Mountains to remain as an uplifted horst block. Based on the significant scarp on the La Serna fault subsidence has continued into the Quaternary.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"16 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":"126631988","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":"Tectonically induced clastic-carbonate depositional sequences of the Pennsylvanian-Permian transition in the Rowe-Mora Basin, northern New Mexico","authors":"K. Krainer, S. Lucas, B. Kues","doi":"10.56577/ffc-55.314","DOIUrl":"https://doi.org/10.56577/ffc-55.314","url":null,"abstract":"A BSTRACT .— One of the few places in the late Paleozoic Rowe-Mora basin of northern New Mexico that preserves a section through the traditional Pennsylvanian-Permian boundary is near Canovas Canyon in the Sangre de Cristo Mountains, northwest of Las Vegas. At this section, the Alamitos Formation is ~ 172 m thick and has late Desmoinesian fusulinids in its lower part, and late Virgilian-Wolfcampian fusulinid and invertebrate macrofossils in its upper part. Macrofossil assemblages consist largely of crinoid and bryozoan fragments, and brachiopods (chiefly Composita subtilita and Neosprifer dunbari ), indicating shallow, normal marine carbonate shelf depositional environments. The Alamitos Formation at Canovas Canyon was deposited on the northern part of the Pecos shelf and is composed of nonmarine (arkosic sandstone, conglomerate, and reddish-purple shale) and marine (shale and limestone) lithofacies. These lithofacies form six, well-developed asymmetrical transgressive-regressive (T-R) depositional sequences. There is much evidence of synsedimentary tectonics of the ancestral Rocky Mountain deformation in the Rowe-Mora basin during the Late Pennsylvanian, and formation of the Alamitos Formation depositional sequences at Canovas Canyon is interpreted as having largely been induced by tectonic movements. Eustatic sea-level changes caused by the Gondwana glaciation, which are responsible for cyclic sedimentation on tectonically stable shelf areas during the late Paleozoic, are interpreted as being of lesser importance in the Canovas Canyon section.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"56 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":"126855225","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":"Chemical and isotopic constraints on source-waters and connectiviity of basin-fill aquifers","authors":"P. Drakos, K. Sims, J. Riesterer, J. Blusztajn, J. Lazarus","doi":"10.56577/ffc-55.405","DOIUrl":"https://doi.org/10.56577/ffc-55.405","url":null,"abstract":"A BSTRACT . — Selected wells and surface water sources in the Taos Valley have been sampled and analyzed for major anions and cations, trace metals, 87 Sr/ 86 Sr, 3 H, δ 2 H, and δ 18 O. 87 Sr/ 86 Sr varies from 0.7074 to 0.7156, indicating water-rock interaction with variable source rocks. Because these waters have relatively enriched 87 Sr/ 86 Sr it is likely that the Pennsylvanian carbon- ates and granitic basement rocks have contributed significantly to their Sr isotopic compositions. Tritium results indicate that recharge to the shallow aquifer occurs on a time scale of < 5 to 10 years, but that recharge to some deep alluvial wells and Agua Azul (Servilleta Formation) wells occurs on a time scale of > 50 years. Recharge into the mountain front fractured bedrock aquifers occurs on time scales ranging from < 5 to 10 years to > 50 years. δ 2 H and δ 18 O data suggest that some deep basin-fill aquifer wells have received older (Pleistocene) recharge, whereas other deep wells have received Holocene recharge. Some compartmentalization of the Tertiary aquifer system is indicated by these results. This aquifer compartmentalization is likely caused by intrabasin faults such as the Seco fault that exhibit significant offset.","PeriodicalId":224165,"journal":{"name":"Geology of the Taos Region","volume":"19 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":"121037615","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}