San Juan Basin IV最新文献_第4页

Hydrologic characteristics of the Ojo Alamo Sandstone, San Juan Basin, New Mexico 新墨西哥州圣胡安盆地Ojo Alamo砂岩的水文特征

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.409

Clay L. Kilmer, T. E. Kelly

引用次数: 0

Volcanic geology of the Rio Puerco necks 里约热内卢普尔科颈的火山地质

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.135

{"title":"Volcanic geology of the Rio Puerco necks","authors":"","doi":"10.56577/ffc-43.135","DOIUrl":"https://doi.org/10.56577/ffc-43.135","url":null,"abstract":"-The volcanic necks of the Rio Puerco Valley are among the most concentrated and best preserved examples in the world. They formed by erosion of poorly consolidated pyroclastic material surrounding a more resistant basaltic core. Throughout the valley, necks are preserved over a continuum of erosional sttges. A partially exhumed scoria cone near Cerro de Nuestra Senora represents one of the least eroded volcanoes, whereas all that remains of Cabezon Peak is the solidified magma core. Mantle and/or crustal xenoliths occur in about 60% of the necks. Cerros Guadalupe and Negro, in particular, contain an exceptional variety and abundance. A new whole-rock ~'Ari\" Ar plateau age of 2.658 ± 0.032 Ma for Cabezon Peak is consistent with volcanism on the adjacent Mesa Chivato and Mesa Prieta. The two principal types of volcanic features in the Rio Puerco Valley are (I) subaerial volcanic centers 1hat produced surge and pyroclastic beds, lava flows and intrusive cores or crystallized lava lakes, and (2) wholly intrusive structures, such as dikes, which represent only a small part of the volcanic rocks in the valley. Based on field evidence, two models are given to explain the formation of the necks. In the first, a luff ring or scoria cone is built around a central vent, then magma ponds in the vent and solidifies. Later, erosion of the outer cone exposes the plug. This model is more consistent with the larger, more symmetrical necks, such as Cabezon Peak and Cerro de Nuestra Senora. In the second model, magma supply rates are lower, the volcanic cone and conduit smaller, and thermal retention lower. The necks form when small pods of magma intrude into overlying volcanic luffs and breccia near the waning stages of magmatic activity. Those that form by this process display irregular columnar jointing patterns. Most necks in the Rio Puerco Valley are consistent with this latter model.","PeriodicalId":325871,"journal":{"name":"San Juan Basin IV","volume":"47 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":"131901548","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}

引用次数: 4

Gravity and magneitc anomalies in the San Juan Basin area 圣胡安盆地地区重磁异常

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.133

G. Keller, D. Adams

{"title":"Gravity and magneitc anomalies in the San Juan Basin area","authors":"G. Keller, D. Adams","doi":"10.56577/ffc-43.133","DOIUrl":"https://doi.org/10.56577/ffc-43.133","url":null,"abstract":"Regional gravity and magnetic maps that include the San Juan Basin area (e .g., Cordell, 1984: Keller and Cordell , 1984) demonstrate that there arc many significant anomalies present. Here , we present a series of re latively detailed maps that enhance these anomalies and briefly comment on the ir geological significance . Our primary goal is to present these maps for the use of those interested in this region and to illustrate their util ity. GRAVITY AND AEROMAGNETIC ANOMALY MAPS The geophysics group in the Department of Geological Sciences at The University of Texas at El Paso maintains an extensive database of gravity and magnetic measurements . These data were used to construct Bouguer gravity and total magnetic intensity anomaly maps of the San Juan Basin area. The San Juan Basin area contains more than 21,000 gravity and 17,000 magnetic data points. The data sets were processed to form a 2-km grid using a minimum curvature algorithm. A fi rst order polynomial surface was removed from both graips before they were filtered. The filtering algorithm employed was a general ized bandpass/strikepass fi lter based on the Hartley transform (Adams et al. , 1991 ). The maps were filtered to pass wavelengths from 20 km to 800 km . In addition, a gravity map was fi ltered to reject strikes from 85° to 225° east of north . These strikes are perpendicular to the prominent cast-northeast-trending gravity low that crosses the basin. The filtered gravity maps (Figs. I and 2) are dominated by maxima associated with basement uplifts. The Nacimiento and Zuni uplifts are of primary interest here. The northwest-trending gravity high associated with the Zuni uplift indicates that this feature is much larger than the actual Precambrian outcrop area . As di scussed by Woodward et al. (this volume), the Nac imiento upli ft and its bounding fau lts have been of interest for many years. The gravity maxima associated with this uplift correlate very well with the outcrop area. The steep gravity gradient FIGURE I . Residual gravity anomaly map, filtered to pass wavelengths from 20 to 800 km. on the west side of the uplift attests to the steep dip and large throw on th is fault. There is a distinct regional east-northeast grain in the gravity map shown in Fig . I. This trend correlates with the dominant anomaly in the aeromagnetic map discussed below. and gravity anomalies with this trend were enhanced to produce the map shown in Fig. 2. This map demonstrates the importance of Precambrian features, which reflect the evol ution of the crust in this region. The dominant feature on the aeromagnctic anomaly map (Fig . 3) is the northeast-trend ing low that extends across the San Juan Basin. passing just north of the Nacimiento uplift. Cordell and Keller ( 1984) showed that th is anomaly passes through the Rio Grande rift onto the Great Plai ns. This anomaly is offset as it crosses the rift and the Sangre de Cristo Mountai ns, indicating the presence of a series of right later","PeriodicalId":325871,"journal":{"name":"San Juan Basin IV","volume":"332 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":"133016755","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}

引用次数: 1

James Hervey Simpson and the first record of San Juan Basin geology 詹姆斯·赫维·辛普森首次记录了圣胡安盆地的地质情况

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.83

B. Kues

引用次数: 1

Ground-water resources of the southeastern San Juan Basin 圣胡安盆地东南部地下水资源

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.407

W. Stone

引用次数: 0

Triassic stratigraphy and paleontology, Chama Basin and adjacent areas, north-central New Mexico 三叠纪地层学与古生物学，查马盆地及邻近地区，新墨西哥州中北部

San Juan Basin IV Pub Date : 1900-01-01 DOI: 10.56577/ffc-43.151

S. Lucas, A. Hunt

{"title":"Triassic stratigraphy and paleontology, Chama Basin and adjacent areas, north-central New Mexico","authors":"S. Lucas, A. Hunt","doi":"10.56577/ffc-43.151","DOIUrl":"https://doi.org/10.56577/ffc-43.151","url":null,"abstract":"~Triass ic strala in the Chama Basin and along the flanks of the Nacimiento and Jemez Mountains of Rio Arriba and Sandoval Counties, New Mexico , pertain to the Middle Triassic Moenkopi Formati on (Anton Chico Member) and the Upper Triassic Chinle Group (Agua Zarca, Sali tral , Poleo, Petrified Forest and Roc k Point Fomiations) . The Mocnko pi Formation is present only along the flanks of the Nacimiento and Jemez Mountains in Sandoval County. It is as much as 39 m thick and consists most ly of grayish red siltstone , mudstone and immature , trough-crossbedded sandstone. The Agua Zarca Formation is as much as 61 m thick and consists mostly of trough-crossbedded. q uartzose sandstone and siliceous conglomerate. Near Coyote in Rio Arriba County, it overlies \" mott led strata\" developed in the top of the Pennsy lvanian-Permian Cutler Form ation. The Salitral Formation is as much as 102 m of mostly purpl ish, smcct iti c mudstone. The Poleo Formation is up to 41 m thick and is mostly grayish ye llow, trough-crossbedded litharenites and subarkoses and minor amounts of both intrabasinal and siliceous conglomerate . Above the Poleo Formation , as much as 200 m of strata , dominated by reddi sh brown, smectitic mud stones, constitute the Petrifi ed Forest Formation . South of San Miguel Canyon in Sandoval County, the Poleo Format ion is not present. and all of the mudstonc sec tion above the Agua Zarca Formation is ass igned lo the Petrifi ed Forest Formation . Locally, near San Ysidro , the Correo Member is present at the top of the Pet rified Forest Formation. In the Chama physiographic bas in, the Rock Point Fom1a1ion, as much as 70 m thick and mostly reddish brown and gray ish red siltstone and ripplelaminar sandstone , disconformably overlies the Petrified Forest Formation. Three formations of the Chinle Group in north-central New Mexico contain biochronologically important fossils. notably the aetosaur Lonxosuch1u (late Camian) in the Salitral Formati on , the aetosaur Tvpothorax and the phytosaur Pseudopalatu.1· (early -middle Norian) in the Petrified Forest Formation, and a new genus of phytosaur (late Norian/Rhaet ian) in the Rock Point Formation. These foss ils and li thostratigraphy allow prec ise correlation of the Chinle Group strata exposed in north-central New Mexico with other Upper Triassic strata in New Mexico.","PeriodicalId":325871,"journal":{"name":"San Juan Basin IV","volume":"34 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":"129503625","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}

引用次数: 27