scholarly journals Contrasting hydrothermal activity at Sierra Negra and Alcedo volcanoes, Galapagos Archipelago, Ecuador

2000 ◽  
Vol 62 (1) ◽  
pp. 34-52 ◽  
Author(s):  
Fraser Goff ◽  
Gary M. McMurtry ◽  
Dale Counce ◽  
James A. Simac ◽  
Alfredo R. Roldán-Manzo ◽  
...  
Keyword(s):  
Hydrothermal Activity ◽  
Galapagos Archipelago ◽  
Sierra Negra

Fumarole/plume and diffuse CO2 emission from Sierra Negra caldera, Galapagos archipelago

2012 ◽  
Vol 74 (6) ◽  
pp. 1509-1519 ◽  
Author(s):  
Eleazar Padrón ◽  
Pedro A. Hernández ◽  
Nemesio M. Pérez ◽  
Theofilos Toulkeridis ◽  
Gladys Melián ◽  
...  
Keyword(s):  
Co2 Emission ◽  
Galapagos Archipelago ◽  
Diffuse Co2 Emission ◽  
Sierra Negra

scholarly journals Three-dimensional attenuation model of Sierra Negra Volcano, Galápagos Archipelago

2016 ◽  
Vol 43 (12) ◽  
pp. 6259-6266 ◽  
Author(s):  
Rebecca L. Rodd ◽  
Jonathan M. Lees ◽  
Gabrielle Tepp
Keyword(s):  
Three Dimensional ◽  
Attenuation Model ◽  
Galapagos Archipelago ◽  
Sierra Negra Volcano ◽  
Sierra Negra

Hydrothermal activity in the Upper Permian Ravnefjeld Formation of central East Greenland – a study of sulphide morphotypes

1998 ◽  
pp. 81-87
Author(s):  
Jesper Kresten Nielsen ◽  
Mikael Pedersen
Keyword(s):  
Base Metal ◽  
Early Period ◽  
Sedimentary Basins ◽  
Hydrothermal Activity ◽  
Source Rocks ◽  
Upper Permian ◽  
Thermal Activity ◽  
East Greenland ◽  
The North ◽  
Alum Shale

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kresten Nielsen, J., & Pedersen, M. (1998). Hydrothermal activity in the Upper Permian Ravnefjeld Formation of central East Greenland – a study of sulphide morphotypes. Geology of Greenland Survey Bulletin, 180, 81-87. https://doi.org/10.34194/ggub.v180.5090 _______________ Bituminous shales of the Ravnefjeld Formation were deposited in the subsiding East Greenland basin during the Upper Permian. The shales are exposed from Jameson Land in the south (71°N; Fig. 1) to Clavering Ø in the north (74°20′N) and have attracted considerable attention due to their high potential as hydrocarbon source rocks (Piasecki & Stemmerik 1991; Scholle et al. 1991; Christiansen et al. 1992, 1993a, b). Furthermore, enrichment of lead, zinc and copper has been known in the Ravnefjeld Formation on Wegener Halvø since 1968 (Lehnert-Thiel 1968; Fig. 1). This mineralisation was assumed to be of primary or early diagenetic origin due to similarities with the central European Kupferschiefer (Harpøth et al. 1986). Later studies, however, suggested base metal mineralisation in the immediately underlying carbonate reefs to be Tertiary in age (Stemmerik 1991). Due to geographical coincidence between the two types of mineralisation, a common history is a likely assumption, but a timing paradox exists. A part of the TUPOLAR project on the ‘Resources of the sedimentary basins of North and East Greenland’ has been dedicated to re-investigation of the mineralisation in the Ravnefjeld Formation in order to determine the genesis of the mineralisation and whether or not primary or early diagenetic base metal enrichment has taken place on Wegener Halvø, possibly in relation to an early period of hydrothermal activity. One approach to this is to study the various sulphides in the Ravnefjeld Formation; this is carried out in close co-operation with a current Ph.D. project at the University of Copenhagen, Denmark. Diagenetically formed pyrite is a common constituent of marine shales and the study of pyrite morphotypes has previously been successful from thermalli immature parts of elucidating depositional environment and thermal effects in the Alum Shale Formation of Scandinavia (Nielsen 1996; Nielsen et al. 1998). The present paper describes the preliminary results of a similar study on pyrite from thermally immature parts of the Ravnefjeld Formation which, combined with the study of textures of base metal sulphides in the Wegener Halvø area (Fig. 1), may provide an important step in the evaluation of the presence or absence of early thermal activity on (or below) the Upper Permian sea floor.

New constraints from zircon, monazite and uraninite dating on the commencement of sedimentation in the Cuddapah basin, India

2017 ◽  
Vol 155 (6) ◽  
pp. 1230-1246 ◽  
Author(s):  
DEBIDARSANI SAHOO ◽  
KAMAL LOCHAN PRUSETH ◽  
DEWASHISH UPADHYAY ◽  
SAMEER RANJAN ◽  
DIPAK C. PAL ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Hydrothermal Activity ◽  
Time Span ◽  
Detrital Zircons ◽  
Cuddapah Basin ◽  
Relative Timing ◽  
Considerable Time ◽  
Long Span ◽  
Considerable Confusion ◽  
Age Constraints

AbstractThe Cuddapah basin in southern India, consisting of the Palnad, Srisailam, Kurnool and Papaghni sub-basins, contains unmetamorphosed and undeformed sediments deposited during a long span of time in the Proterozoic. In the absence of robust age constraints, there is considerable confusion regarding the relative timing of sedimentation in these sub-basins. In this study, U–Pb isotopic dating of zircon and U–Th–Pbtotaldating of monazite and uraninite from the gritty quartzite that supposedly belongs to the formation Banganapalle Quartzite have been used to constrain the beginning of sedimentation in the Palnad sub-basin. Magmatic and detrital zircons recording an age of 2.53 Ga indicate that the sediments were derived from the granitic basement or similar sources and were deposited after 2.53 Ga. Hydrothermally altered zircons both in the basement and the cover provide concordant ages of 2.32 and 2.12 Ga and date two major hydrothermal events. Thus, the gritty quartzite must have been deposited sometime between 2.53 and 2.12 Ga and represents the earliest sediments in the Cuddapah basin. Monazite and uraninite give a wide spectrum of ages between 2.5 Ga and 150 Ma, which indicates several pulses of hydrothermal activity over a considerable time span, both in the basement granite and the overlying quartzite. The new age constraints suggest that the gritty quartzite may be stratigraphically equivalent to the Gulcheru Quartzite that is the oldest unit in the Cuddapah basin, and that a sedimentary/erosional hiatus exists above it.

scholarly journals Survival strategies on a semi-arid island: submersion and desiccation tolerances of fiddler crabs from the Galapagos Archipelago

2021 ◽  
Vol 168 (1) ◽  
Author(s):  
Mariana V. Capparelli ◽  
Carl L. Thurman ◽  
Paloma Gusso Choueri ◽  
Denis Moledo de Souza Abessa ◽  
Mayana Karoline Fontes ◽  
...  
Keyword(s):  
Survival Strategies ◽  
Fiddler Crabs ◽  
Galapagos Archipelago ◽  
Semi Arid
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