KarstBase a bibliography database in karst and cave science.
Featured articles from Cave & Karst Science Journals
Characterization of minothems at Libiola (NW Italy): morphological, mineralogical, and geochemical study, Carbone Cristina; Dinelli Enrico; De Waele Jo
Chemistry and Karst, White, William B.
The karst paradigm: changes, trends and perspectives, Klimchouk, Alexander
Long-term erosion rate measurements in gypsum caves of Sorbas (SE Spain) by the Micro-Erosion Meter method, Sanna, Laura; De Waele, Jo; Calaforra, José Maria; Forti, Paolo
The use of damaged speleothems and in situ fault displacement monitoring to characterise active tectonic structures: an example from Zapadni Cave, Czech Republic , Briestensky, Milos; Stemberk, Josef; Rowberry, Matt D.;
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
Earth and Planetary Science Letters, 1987, Vol 81, Issue 0, p. 175-192
238U---234U---230Th---232Th systematics and the precise measurement of time over the past 500,000 years
Lawrence Edwards R. , Chen J. H. , Wasserburg G. J. ,
Abstract:
We have developed techniques to measure the 230Th abundance in corals by isotope dilution mass spectrometry. This, coupled with our previous development of mass spectrometric techniques for 234U and 232Th measurement, has allowed us to reduce significantly the analytical errors in 238U---234U---230Th dating and greatly reduce the sample size. We show that 6 x 108 atoms of 230Th can be measured to 30[per mille sign] (2[sigma]) and 2 x 1010 atoms of 230Th to 2[per mille sign]. The time over which useful age data on corals can be obtained ranges from a few years to ~ 500 ky. The uncertainty in age, based on analytical errors, is 5 y (2[sigma]) for a 180 year old coral (3 g), 44 y at 8294 years and 1.1 ky at 123.1 ky (250 mg of coral). We also report 232Th concentrations in corals (0.083-1.57 pmol/g) that are more than two orders of magnitude lower than previous values. Ages with high analytical precision were determined for several corals that grew during high sea level stands ~ 120 ky ago. These ages lie specifically within or slightly postdate the Milankovitch insolation high at 128 ky and support the idea that the dominant cause of Pleistocene climate change is Milankovitch forcing
We have developed techniques to measure the 230Th abundance in corals by isotope dilution mass spectrometry. This, coupled with our previous development of mass spectrometric techniques for 234U and 232Th measurement, has allowed us to reduce significantly the analytical errors in 238U---234U---230Th dating and greatly reduce the sample size. We show that 6 x 108 atoms of 230Th can be measured to 30[per mille sign] (2[sigma]) and 2 x 1010 atoms of 230Th to 2[per mille sign]. The time over which useful age data on corals can be obtained ranges from a few years to ~ 500 ky. The uncertainty in age, based on analytical errors, is 5 y (2[sigma]) for a 180 year old coral (3 g), 44 y at 8294 years and 1.1 ky at 123.1 ky (250 mg of coral). We also report 232Th concentrations in corals (0.083-1.57 pmol/g) that are more than two orders of magnitude lower than previous values. Ages with high analytical precision were determined for several corals that grew during high sea level stands ~ 120 ky ago. These ages lie specifically within or slightly postdate the Milankovitch insolation high at 128 ky and support the idea that the dominant cause of Pleistocene climate change is Milankovitch forcing
Keywords: abundance, age, ages, climate, climate change, climate-change, corals, dating, dilution, error, errors, isotope, level, magnitude, mass, mass-spectrometry, mg, pleistocene, precision, range, sample, sea, sea level, sea-level, size, stand, stands, support, systematics, time, uncertainty, values,