scholarly journals Igneous and metamorphic rocks of the Serpentine Hot Springs area, Seward Peninsula, Alaska

1979 ◽  
Author(s):  
Travis Hudson
Keyword(s):  
Hot Springs ◽  
Metamorphic Rocks ◽  
Seward Peninsula

scholarly journals Hydrogeochemistry, Geothermometry, and Genesis of the Hot Springs in the Simao Basin in Southwestern China

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
Yuqi Zhang ◽  
Xun Zhou ◽  
Haisheng Liu ◽  
Mingxiao Yu ◽  
Kuo Hai ◽  
...  
Keyword(s):  
Carbonate Rocks ◽  
Hot Springs ◽  
Cold Water ◽  
Metamorphic Rocks ◽  
Formation Mechanisms ◽  
Chemical Compositions ◽  
Red Beds ◽  
Incongruent Dissolution ◽  
Geothermal Waters ◽  
Isotopic Analyses

In the Simao Basin in southwest China widely occur red beds of poor permeability. Nevertheless, more than 100 springs exist in the basin, some of which are hot springs with varying temperature. Hot springs contain abundant information on hydrogeochemical processes and groundwater circulation. In this study, hydrochemical and isotopic analyses and mixed models are used to examine the sources of recharge, heat, and solutes of the hot springs to better understand the subsurface processes and formation mechanisms of different hot springs in the basin. Three types of springs are found in the Simao Basin: springs of HCO3-Na type occur in the metamorphic rocks, springs of HCO3-Ca(Mg) and Cl-HCO3-Na-Ca types in the carbonate rocks, and springs of Cl(SO4)-SO4(Cl)-HCO3-Na(Ca) type in the red beds. Data of δ2H and δ18O indicate that the hot springs in the Simao Basin are meteoric in origin. Incongruent dissolution is the dominant process affecting the chemical compositions of the spring waters. The hydrochemical constituents of the hot springs in the metamorphic rocks, carbonate rocks, and red beds are influenced by the weathering of albite and the dissolution of carbonate, gypsum, anhydrite, and halite. The geothermal waters are mixed with shallow cold waters in their ascending processes, and the mixing ratios of cold water range from 58% to 94%. Due to the effect of mixing, the reservoir temperatures (51°C-127°C) calculated with the quartz geothermometer are regarded as the minimum reservoir temperatures. More reliable reservoir temperatures (91°C-132°C) are estimated with the fixed-Al method. The following mechanisms contribute to the formation of hot springs in the Simao Basin: the groundwater receives recharge from infiltration of precipitation and undergoes deep circulation, during which groundwater is heated by heat flow and incongruently dissolves the subsurface minerals and emerges in the form of hot springs along the permeable fracture or fault zones.

Rb-Sr and K-Ar study of metamorphic rocks of the Seward Peninsula and Southern Brooks Range, Alaska

1986 ◽  
pp. 185-204 ◽  
Author(s):  
Richard L. Armstrong ◽  
Joseph E. Harakal ◽  
Robert B. Forbes ◽  
Bernard W. Evans ◽  
Stephen Pollock Thurston
Keyword(s):  
Metamorphic Rocks ◽  
Brooks Range ◽  
Seward Peninsula

scholarly journals Hydrogeochemistry of Hot Springs and the 2018 Mojiang M 5.9 Earthquake-Related Chemical Changes in the Simao Basin, China

2022 ◽  
Vol 9 ◽  
Author(s):  
Qilin Li ◽  
Ciping Zhao ◽  
Yun Wang ◽  
Yiying Zhou ◽  
Hua Ran
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
Shallow Groundwater ◽  
Tectonic Activity ◽  
Metamorphic Rocks ◽  
Hydrochemical Characteristics ◽  
Deep Faults ◽  
Saline Springs ◽  
Hydrogeochemical Variations ◽  
Saline Spring

The Simao Basin is characterized by strong tectonic activity and frequent seismicity. This study investigated the hydrochemical characteristics of 21 thermal springs in the Simao Basin from 2018 to 2020. In this study period, the 2018 Mojiang M5.9 earthquake caused several hydrochemical changes. The results indicate that the Simao Basin contained saline spring waters, HCO3−-rich spring waters, and SO42−-rich spring waters. In the study area, the water chemistry types were controlled by stratum lithology. Saline springs flowed through red beds and dissolved large amounts of halite, which is a rich source of Cl−and Na+ ions. In the hot spring waters, Ca2+ (Mg2+) and HCO3− were mainly derived from the dissolution of carbonate minerals, gypsum, and anhydrite of Triassic rocks. The higher SO42- content in the hot spring waters was caused by the pyrite present in Ailaoshan metamorphic rocks. The reservoir temperatures (121–289 °C) in the Simao Basin were estimated by the silica-enthalpy mixing model equation and the silica-enthalpy diagram. The hot springs had higher reservoir temperatures (>250 °C) and were mainly located at the edges of the basin. Metamorphic rocks exposed in the region had low permeabilities and these springs was close to nearby deep faults that provided deep heat. In most springs, the concentrations of Ca2+ and HCO3− ions increased obviously before the 2018 Mojiang M5.9 earthquake; however, the concentrations of these ions decreased after the earthquake. The hydrogeochemical variations might be attributed to the vigorous water-rock interactions and the mixing of secondary fluids. The entry of cold shallow groundwater caused changes in the reservoir temperatures of some spring samples.

scholarly journals Hydrogeochemistry of Hot Springs and the 2018 Mojiang M 5.9 Earthquake-Related Chemical Changes in the Simao Basin, China

2021 ◽  
Author(s):  
Qilin Li ◽  
Ciping Zhao ◽  
Yun Wang ◽  
Yiying Zhou ◽  
Hua Ran
Keyword(s):  
Model Equation ◽  
Hot Springs ◽  
Hot Spring ◽  
Tectonic Activity ◽  
Metamorphic Rocks ◽  
Hydrochemical Characteristics ◽  
Deep Faults ◽  
Saline Springs ◽  
Hydrogeochemical Variations ◽  
Saline Spring

Abstract Due to strong tectonic activity, the Simao Basin frequently experiences earthquakes with a magnitude of 6 or greater. This study investigated the hydrochemical characteristics of 21 thermal springs in the Simao Basin from 2018 to 2020 to determine how the 2018 Mojiang M5.9 earthquake caused hydrochemical changes. The results showed that the Simao Basin contained saline spring waters, HCO3−-rich spring waters, and SO42−-rich spring waters. Stratum lithology characteristics in the area exerted obvious control over the water chemistry characteristics. Saline springs flowed through red beds and dissolved large amounts of halite, which is rich with Cl−and Na+. Ca2+ (Mg2+) and HCO3− in the hot spring waters were mainly derived from the dissolution of carbonate minerals, gypsum, and anhydrite in Triassic rocks. The higher SO42− content in the hot spring waters was influenced by pyrite contained in Ailaoshan metamorphic rocks. The reservoir temperatures (121–289° C) in the Simao Basin were estimated by the silica-enthalpy mixing model equation and silica-enthalpy diagram. The hot springs with higher reservoir temperatures (> 250° C) were mainly located at the edges of the basin, which may correlate with nearby deep faults that provided deep heat and metamorphic rocks with low permeabilities. The concentrations of Ca2+ and HCO3− in most springs increased obviously before the Mojiang M5.9 earthquake but decreased after the earthquake. Changes also occurred in the reservoir temperatures of some spring samples. These hydrogeochemical variations might be attributable to accelerated water-rock interactions and/or the mixing of second fluids due to the earthquake.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

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