Velasco Formation

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
×Close Modal
Sort by
Published: 01 December 2016
DOI: 10.5724/gcs.15.35.0479
EISBN: 978-1-944966-10-2
... clasts are thought to have been derived from the Sierra Madre Oriental to the west by the backwash of the tsunami generated by the impact event. In many of the well reports, the wellsite geologists also note that the “Velasco Formation” overlies this breccia. The Velasco Formation is always described...
FIGURES | View All (5)
Journal Article
Published: 01 October 2001
Micropaleontology (2001) 47 (4): 269-316.
...Laia Alegret; Ellen Thomas Abstract The deep-sea, Upper Cretaceous through Paleocene benthic Foraminifera from the Mendez and Velasco Formation (Tampico Embayment, northeastern Mexico) were first described in classical papers of the 1920s. These faunas were among the first deep-water faunas...
Journal Article
Published: 01 July 2007
Seismological Research Letters (2007) 78 (4): 446-453.
...A. A. Velasco; V. L. Gee; C. Rowe; D. Grujic; L. S. Hollister; D. Hernandez; K. C. Miller; T. Tobgay; T. Tobgay; M. Fort; S. Harder; S. Harder Abstract We processed data from a small, five-station temporary seismic network deployed from January 2002 until March 2003 within the Kingdom of Bhutan. We...
FIGURES | View All (4)
Journal Article
Journal: Geology
Published: 01 March 1996
Geology (1996) 24 (3): 255-258.
... spherule-bearing clastic unit located precisely at the K-T boundary. The sections consist of uppermost Maastrichtian ( Micula prinsii Zone) marly limestones of the Mendez Formation and marlstones of the lower Paleocene (Zone NP1) Velasco Formation separated by a distinct, 1–3-m-thick sandstone unit...
Journal Article
Published: 01 July 2011
Journal of the Geological Society (2011) 168 (4): 1061-1071.
... that the craton reached its current relative position in the Mid- to Late Cambrian, after the main Pampean tectonothermal event (530–520 Ma) and before deposition of the La Cébila protolith and the Achavil Formation (Sierra de Famatina), which contain comparable detrital zircon populations. This work...
FIGURES | View All (5)
Journal Article
Published: 15 December 2009
Geological Magazine (2009) 147 (3): 451-468.
...’ does not seem viable since no evidence of a mafic component has been found. The orbicular granitoid of the Sierra de Velasco has exceptional petrological and geochemical characteristics that imply special conditions and processes of formation. In the following sections, we discuss different aspects...
Journal Article
Published: 01 December 2003
Mineralogical Magazine (2003) 67 (6): 1253-1268.
... vermiculite. This result has been related to the interlayer Mg-cation content, due to its affinity to water molecules. The interstratified states have been analysed by the direct Fourier-transform method. The vermiculite from Sta. Olalla exhibits the most complex process, with formation of three different...
FIGURES | View All (15)
Journal Article
Journal: GSA Bulletin
Published: 29 June 2018
GSA Bulletin (2018) 130 (11-12): 1842-1858.
... of exhumation and uplift of these ranges remains enigmatic. This study presents new thermochronology and field observations from the Sierra de Velasco, one of the highest relief (>4 km) and least studied mountains in the Sierras Pampeanas. Advances in the annealing and diffusion kinetics of the apatite...
FIGURES | View All (12)
Journal Article
Published: 03 February 2015
The Canadian Mineralogist (2015) 52 (5): 809-836.
...Fernando G. Sardi; Adriana Heimann A bstract Rare-element class, beryl type, beryl-columbite-phosphate subtype pegmatites of the Velasco district from the Pampeana Pegmatite Province, Argentina, contain varieties of green, yellow, and aquamarine beryl. The major and trace element chemistry...
FIGURES | View All (11)
Series: Geological Society, London, Special Publications
Published: 01 January 2011
DOI: 10.1144/SP350.10
EISBN: 9781862395985
... Abstract In the Sierra de Velasco, northwestern Argentina, undeformed Lower Carboniferous granitoids (350–334 Ma) intrude deformed Lower Ordovician granites and have been emplaced by passive mechanisms, typical of tensional environments. The semi-elliptic, about 300 km 2 shallow-emplaced San...
FIGURES | View All (10)
Journal Article
Published: 24 May 2013
Geological Magazine (2013) 150 (6): 1047-1061.
..., 1981 ; Alonso, 1987 a , b ). As in the rest of the CZ, the main décollement level of the thrusts is located at the base of the Láncara Formation (Lower–Middle Cambrian). Displacement of the thrust units was probably firstly northwards and later towards the NE, with an accumulated...
FIGURES | View All (11)
Series: Geological Society, London, Special Publications
Published: 01 January 2005
DOI: 10.1144/GSL.SP.2005.245.01.20
EISBN: 9781862394933
... Abstract A Geographical Information System (GIS) has been applied to shape-fabric analysis and strain measurement. It works in either raster or vectorial format, allows determination of many geometrical features of grains and stores additional descriptive information linked to all these graphic...
FIGURES | View All (6)
Journal Article
Published: 06 March 2018
Bulletin of the Seismological Society of America (2018) 108 (2): 604-618.
... ), and some minor NE faults, both of which were later reactivated during the Alpine convergence. The main rifting episode in the Mesozoic resulted in the opening of the Bay of Biscay and the formation of a new plate boundary between Iberia and Europe that was closed later during the Alpine orogeny. Between...
FIGURES | View All (7)
Journal Article
Published: 01 April 2009
Mineralogical Magazine (2009) 73 (2): 269-284.
... and growth are also discussed. Finally, an X-ray diffraction analysis of the precipitates provided no evidence of the formation of the dolomite-type ordered kutnahorite [CaMn(CO 3 ) 2 ] in any of the experimental sets. In the Lippmann model, the key concept is the `total solubility product', σΠ, which...
FIGURES | View All (9)
Journal Article
Published: 01 November 2003
European Journal of Mineralogy (2003) 15 (6): 1069-1077.
... are calcite, quartz, hydroxyapophyllite, hydroandradite, prehnite, pumpellyite-(Fe +2 ), Cu-sulphides and electrum. The babingtonite formation is related to the locally Aldepleted aqueous fluids at relative high fO 2 and low XCO 2 . Babingtonite [Ca 2 Fe 2+ Fe 3+ Si 5 O 14 (OH)] is a hydrated calcic-ferrous...
FIGURES | View All (6)
Journal Article
Published: 15 August 2014
Geological Magazine (2014) 152 (2): 341-350.
...M.A. LOPEZ-SANCHEZ; A. IRIONDO; A. MARCOS; F.J. MARTÍNEZ Abstract The uppermost metavolcanic layer of the Cambro-Ordovician Ollo de Sapo Formation, the largest accumulation of pre-Variscan igneous rocks in the Iberian Peninsula, have been dated in its northernmost part using U–Pb SHRIMP-RG zircon...
FIGURES | View All (5)
Journal Article
Published: 01 October 2002
The Canadian Mineralogist (2002) 40 (5): 1505-1520.
.... Concentrations of total C, organic C and S were established with a LECO apparatus, and the other elements, by ICP–MS analysis ( Table 1 ). Finally, we have attempted to model the field stress for groups 1 and 2 ( Fig. 6 ). The position of σ 1 before ore formation may be NW–SE, as shown...
FIGURES | View All (10)
Journal Article
Journal: Geosphere
Published: 30 May 2018
Geosphere (2018) 14 (4): 1635-1656.
...” files, it is necessary to change the file format. This can be achieved, as, indeed, was done in this research, using the open source tool MeshLab (available for free at http://meshlab.sourceforge.net/ ), wherein it is also feasible to remove unneeded areas or select only those parts of interest...
FIGURES | View All (16)
Journal Article
Published: 01 February 2008
Mineralogical Magazine (2008) 72 (1): 277-281.
... loss of 75% of the water molecules and the formation of basanite (CaSO 4 .0.5H 2 O), followed by complete dehydration to form anhydrite (γ-CaSO 4 ). In contrast, brushite dehydrates to form monetite (CaHPO 4 ) in a single step, at 125°C. This value is slightly smaller than the range expressed...
Journal Article
Published: 01 February 2009
American Mineralogist (2009) 94 (2-3): 313-322.
... simultaneously and have similar structures, the formation of solid solutions and/or epitaxies is always a possibility, which is important not only from a fundamental point of view, but also from an applied perspective. For instance, the formation of solid solutions of anionic substitution has been investigated...
FIGURES | View All (8)