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Community news

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That hydrophobic is the repelling of water [16].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms


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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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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;
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Your search for recession (Keyword) returned 80 results for the whole karstbase:
Showing 31 to 45 of 80
Simulation of daily and monthly stream discharge from small watersheds using the SWAT model, 2000,
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Spruill C. A. , Workman S. R. , Taraba J. L. ,
The Soil and Water Assessment Tool (SWAT) was evaluated and parameter sensitivities were determined while modeling daily streamflows in a small central Kentucky watershed over a two-year period. Streamflow data from 1996 were used to calibrate the model and streamflow data from 1995 were used for evaluation. The model adequately predicted the trends in daily streamflow during this period although Nash-Sutcliffe R-2 values were -0.04 and 0.19 for 1995 and 1996, respectively The model poorly predicted the timing of some peak flow values and recession rates during the last half of 1995. Excluding daily peak flow values from August to December improved the daily R-2 to 0.15, which was similar to the 1996 daily R2 value. The Nash-Sutcliffe R-2 for monthly total flows were 0.58 for 1995 and 0.89 for 1996 which were similar to values found in the literature. Since very little information was available on the sensitivity of the SWAT model to various inputs, a sensitivity analysis/calibration procedure was designed to evaluate parameters that were thought to influence stream discharge predictions. These parameters included, drainage area, slope length, channel length, saturated hydraulic conductivity, and available water capacity. Minimization of the average absolute deviation between observed and simulated streamflows identified optimum values/ranges for each parameter. Saturated hydraulic conductivity alpha baseflow factor; drainage area, channel length, and channel width were the most sensitive parameters in modeling the karst influenced watershed. The sensitivity analysis process confirmed die trace studies in the karst watershed that a much larger area contributes to streamflow than can be described by the topographic boundaries. Overall, the results indicate that the SWAT model can be an effective tool for describing monthly, runoff from small watersheds in central Kentucky that have developed on karat hydrology however calibration data are necessary to account for solution channels draining into or out of the topographic watershed

Hydrogeological characteristics of a karst mountainous catchment in the northwest of Vietnam, 2001,
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Tam V. T. , Vu T. M. N. , Batelaan O. ,
This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is located at 600 -700 in a.s.l. and covers an area of 284 kin. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including geological and hydrogeological. field surveys, cave surveys, dye-tracer tests, meteorological and surface water monitoring. Geological studies and cave surveys have identified the most important active cave/conduit systems within the catchment. Although these data are essential, they are insufficient to make a comprehensive appraisal of the hydrologic nature of the catchment under interest. An attempt was made to calculate a global water balance of the catchment, based on short-term (15 months) meteorological and streamflow records. The results show that, despite the existence of a number of substantial cavern conduit systems, the groundwater system of the catchment is governed by the fracture/fissure matrix. The cavern conduit systems only collect groundwater from the adjacent fracture matrix and/or connect topographically isolated surface watercourses. The groundwater storage of the cavern conduit systems appears to be regionally insignificant in comparison with the governed fracture matrix groundwater system

Spatial and temporal patterns of bacterial density and metabolic activity in a karst aquifer, 2001,
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Simon K. S. , Gibert J. , Petitot P. , Laurent R. ,
Karst aquifers are heterotrophic ecosystems fueled by organic matter imported from the surface. The temporal pattern of floods influences organic matter import and the spatial distribution of organic matter and biofilms in aquifer structural zones. We investigated spatial and temporal patterns of bacterial density and activity as indicators of energy availability and microbial dynamics in a karst aquifer. During baseflow, bacterial density and microbial hydrolytic activity were similar in the upper and lower zones of the aquifer. Floods apparently scoured aquifer biofilms and trans ported soil bacteria into the aquifer, increasing inactive bacterial density in the water column. Respiring bacterial density did not respond to floods and changed little over time. The overall proportion of total bacteria that were respiring was very high on some dates, resulting from a reduction of inactive cell density during flood recession. Floods appear to be key events in scouring senescent microbial assemblages in karst aquifers and stimulating microbial recolonization of the aquifer matrix. We conclude that a conceptual model of karst aquifer structure and function should incorporate changes caused by alternation between flooding and drying in the aquifer

Geochronology of late Pleistocene to Holocene speleothemsfrom central Texas: Implications for regional paleoclimate, 2001,
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Musgrove Marylynn, Banner Jay L. , Mack Larry E. , Combs Deanna M. , James Eric W. , Cheng Hai, Edwards R. Lawrence,
A detailed chronology for four stalagmites from three central Texas caves separated by as much as 130 km provides a 71 000-yr record of temporal changes in hydrology and climate. Mass spectrometric 238U-230Th and 235U-231Pa analyses have yielded 53 ages. The accuracy of the ages and the closed- system behavior of the speleothems are indicated by interlaboratory comparisons, concordance of 230Th and 231Pa ages, and the result that all ages are in correct stratigraphic order. Over the past 71 000 yr, the stalagmites have similar growth histories with alternating periods of relatively rapid and slow growth. The growth rates vary over more than two orders of magnitude, and there were three periods of rapid growth: 71-60 ka, 39-33 ka, and 24-12 ka. These growth-rate shifts correspond in part with global glacial-interglacial climatic shifts. Paleontological evidence indicates that around the Last Glacial Maximum (20 ka), climate in central Texas was cooler and wetter than at present. This wetter interval corresponds with the most recent period of increased growth rates in the speleothems, which is consistent with conditions necessary for speleothem growth. The temporal shift in wetness has been proposed to result from a southward deflection of the jet steam due to the presence of a continental ice sheet in central North America. This mechanism also may have governed the two earlier intervals of fast growth in the speleothems (and inferred wetter climate). Ice volumes were lower and temperatures in central North America were higher during these two earlier glacial intervals than during the Last Glacial Maximum, however. The potential effects of temporal variations in precession of Earth's orbit on regional effective moisture may provide an additional mechanism for increased effective moisture coincident with the observed intervals of increased speleothem growth. The stalagmites all exhibit a large drop in growth rate between 15 and 12 ka, and they show very slow growth up to the present, consistent with drier climate during the Holocene. These results illustrate that speleothem growth rates can reflect the regional response of a hydrologic system to regional and global climate variability

Interpretation of spring recession curves, 2002,
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Amit H, Lyakhovsky V, Katz A, Starinsky A, Burg A,
Recession curves contain information on storage properties and different types of media such as porous, fractured, cracked lithologies and karst. Recession curve analysis provides a function that quantitatively describes the temporal discharge decay and expresses the drained volume between specific time limits (Hall 1968). This analysis also allows estimating the hydrological significance of the discharge function parameters and the hydrological properties of the aquifer. In this study, we analyze data from perennial springs in the Judean Mountains and from others in the Galilee Mountains, northern Israel. All the springs drain perched carbonate aquifers. Eight of the studied springs discharge from a karst dolomite sequence, whereas one flows out from a fractured, slumped block of chalk. We show that all the recession curves can be well fitted by a function that consists of two exponential terms with exponential coefficients alpha(1) and alpha(2). These coefficients are approximately constant for each spring, reflecting the hydraulic conductivity of different media through which the ground water flows to the spring. The highest coefficient represents the fast flow, probably through cracks, or quickflow, whereas the lower one reflects the slow flow through the porous medium, or baseflow. The comparison of recession curves from different springs and different years leads to the conclusion that the main factors that affect the recession curve exponential coefficients are the aquifer lithology and the geometry of the water conduits therein. In normal years of rainy winter and dry summer, (Xi is constant in time. However, when the dry period is longer than usual because of a dry winter, (X, slightly decreases with time

A global experimental system approach of karst springs' hydrographs and chemographs, 2002,
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Grasso D. A. , Jeannin P. Y. ,
Investigation techniques for karst flow systems are based mainly on the study of different signals leaving the system caused by natural or induced external influences. Each signal represents one of the systems outputs (e.g., hydraulic, chemical, physical, or isotopic responses) that reflect the characteristics of the entire system. In this paper, we present a method to infer information about the structure of karst systems. It is based on a simultaneous analysis of chemical and hydraulic responses. Beside the classical piston flow at the beginning of a flood pulse, we define a chemically based recession flow phase. During this phase, field data show that the concentration of total dissolved solids can be considered as an exponential function of the logarithm of flow. This relationship allows two parameters to be defined, one of which is dependent on the structure and degree of development of the karst conduit network, the other is dependent mainly on bioclimatic factors. Data collected from seven karst springs are used to support ideas introduced in the paper

Inferring source waters from measurements of carbonate spring response to storms, 2002,
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Desmarais K, Rojstaczer S,
We infer information about the nature of groundwater flow within a karst aquifer from the physical and chemical response of a spring to storm events. The spring discharges from the Maynardville Limestone in Bear Creek Valley, Tennessee. Initially, spring discharge peaks approximately 1-2 h from the midpoint of summer storms. The initial peak is likely due to surface loading, which pressurizes the aquifer and results in water moving out of storage. All of the storms monitored exhibited recessions that follow a master recession curve very closely, indicating that storm response is fairly consistent and repeatable, independent of the time between storms and the configuration of the rain event itself. Electrical conductivity initially increases for 0.5-2.9 days (longer for smaller storms), the result of moving older water out of storage. This is followed by a 2.1-2.5 day decrease in conductivity, resulting from an increasing portion of low conductivity recharge water entering the spring. Stable carbon isotope data and the calcite saturation index of the spring water also support this conceptual model. Spring flow is likely controlled by displaced water from the aquifer rather than by direct recharge through the soil zone. (C) 2002 Elsevier Science B.V. All rights reserved

The situation and dynamics of the North Yorkshire windypits: A geophysical and geomorphological investigation, MSc Thesis [Engineering Geology], 2002,
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Devlin, R.

ub-surface slip-rift fissures and shafts, known locally as 'windypits', are numerous in the Upper Jurassic strata of the Hambleton Hills and Ryedale district of North Yorkshire. Windypits are predominantly open gull-formations, formed as a result of cambering between competent Corallian Group sandstone and limestone beds above weak clay beds of the Oxford Clay Formation. They relate to the natural pattern of steeply-dipping, widened joint-plane discontinuities, with individual blocks of caprock moving relative to one another along these surfaces. The most extensive fissure systems are up to 40m deep and over 300m long, and typically run sub-parallel to slope contours and linear topographic features, rupturing the surface above the line of maximum gradient. More complex and unpredictable structures occur where there is more than one direction of movement, resulting in a radial fissure network. Windypits have been associated with other forms of scarp recession and landslide activity, most notably the formation of unstable block detachments along vertical cliff-exposures. Aerial photographic interpretation and terrain analysis based on field observations and mapping have been used here in a detailed geomorphological investigation of windypit structures and their related landforms. They appear to play a significant role within a far more complex model of superficial slope evolution, with important consequences for rock-slope stability. The potential hazards from landslides and natural cavities are also assessed in the light of engineering geological evaluation. Shallow geophysical surveying techniques have been used to profile the electrical contrasts between void space and host rock, at a number of selected sites. It has been found that non-contacting electromagnetic conductivity methods are unsuitable for producing a discrete windypit anomaly, due to their limited depth of penetration. Tomographic resistivity techniques appear to be the most promising for accurately locating sub-surface fissures, and helping to map their true depth and full extent Comprehensive ground investigation would allow better interpretation of the geophysical data collected.


Underground Water Flow from the Tržiščica Sinking Stream (SE Slovenia), 2002,
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Kogovš, Ek Janja, Petrič, Metka

A tracing test with injection of uranine in the sinking stream Tr¾i¹èica (SE Slovenia) was carried out at the hydrological conditions of recession from medium to low waters. Concentrated flow towards the springs Tominèev studenec, Javornikov izvir and Debeljakov izvir near the village Dvor in the Krka valley was proved. Apparent flow velocities between 2.4 and 4.6 cm/s were obtained, and the share of recovered tracer was estimated to 2/3 of the injected amount. In the Podpe¹ka jama cave the tracer in lower concentrations was detected only after heavy rain occurred after two months of low water. The apparent flow velocity of 0.1 cm/s was calculated. Obtained results, together with the outcomes of the previous tracing tests, indicate that hydrological conditions significantly influence the underground water flow from the Tr¾i¹èica sinking stream.


'Canons' revisited and reviewed: Lester King's views of landscape evolution considered 50 years later, 2003,
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Twidale C. R. ,
Fifty years after its publication, Lester King's Canons of Landscape Evolution is reviewed and is considered in light of subsequent trends and actual developments. Some of his ideas, such as the role of scarp recession and the antiquity of some surfaces, remain current. His broad view of the world and his interest in major relief anticipated trends that are now fashionable. Some of his interpretations, however, and in particular his downgrading of the importance of structural factors and his linking of scarp retreat and pedimentation, have not stood the test of time. Other concepts, such as the etch or two-stage origin of forms, which were mooted but not fully appreciated in King's day, have come to the forefront, and technological advances in dating and survey, particularly of the ocean floors, have signaled new perspectives in landscape interpretation. Nevertheless, King's was a courageous attempt to provide guidelines for landscape study

Evaluation of aquifer thickness by analysing recession hydro-graphs. Application to the Oman ophiolite hard-rock aquifer, 2003,
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Dewandel A. , Lachassagne P. , Bakalowicz M. Et Al.

Evaluation of aquifer thickness by analysing recession hydrographs. Application to the Oman ophiolite hard-rock aquifer, 2003,
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Dewandel B, Lachassagne P, Bakalowicz M, Weng P, Almalki A,
For more than a century, hydrologists and hydrogeologists have been investigating the processes of stream and spring baseflow recession, for obtaining data on aquifer characteristics. The Maillet Formula [Librairie Sci., A. Hermann, Paris (1905) 218], an exponential equation widely used for recession curve analysis, is an approximate analytical solution for the diffusion equation in porous media whereas the equation proposed by Boussinesq [C. R. Acad. Sci. 137 (1903) 5; J. Math. Pure Appl. 10 (1904) 5], that depicts baseflow recession as a quadratic form, is an exact analytical solution. Other formulas currently used involve mathematical functions with no basis on groundwater theory. Only the exact analytical solutions can provide quantitative data on aquifer characteristics. The efficiency of the two methods was compared on the basis of recession curves obtained with a 2D cross-sectional finite differences model that simulates natural aquifers. Simulations of shallow aquifers with an impermeable floor at the level of the outlet show that their recession curves have a quadratic form. Thus, the approximate Maillet solution largely overestimates the duration of the 'influenced' stage and underestimates the dynamic volume of the aquifer. Moreover, only the Boussinesq equations enable correct estimates of the aquifer parameters. Numerical simulations of more realistic aquifers, with an impermeable floor much deeper than the outlet, proves the robustness of the Boussinesq formula even under conditions far from the simplifying assumptions that were used to integrate the diffusion equation. The quadratic form of recession is valid regardless of the thickness of the aquifer under the outlet, and provides good estimates of the aquifer's hydrodynamic parameters. Nevertheless, the same numerical simulations show that aquifers with a very deep floor provide an exponential recession. Thus, in that configuration, the Maillet formula also provides a good fit of recession curves, even if parameter estimation remains poor. In fact, the recession curve appears to be closer to exponential when flow has a very important vertical component, and closer to quadratic when horizontal flow is dominant. As a consequence, aquifer permeability anisotropy also changes the recession form. The combined use of the two fitting methods allows one to quantify the thickness of the aquifer under the outlet. (C) 2003 Elsevier Science B.V. All rights reserved

A deterministic approach to the coupled analysis of karst springs' hydrographs and chemographs, 2003,
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Grasso D. A. , Jeannin P. Y. , Zwahlen F. ,
During the chemically based recession flow phase of karstic springs the carbonate (dissolved limestone) concentration can be expressed as negative power of the flow rate. The empirically determined Conc/Q relationship allows two parameters (alpha and A) to be defined, of which one (alpha) depends on the geometric dimensions of the saturated (submerged) karstic network. In this paper we present a deterministic model which simulates the concentration of carbonate at the outlet of a network of circular rectilinear conduits as a function of flow rate. This model, based on hydraulic principles and the calcite dissolution kinetics, allows the sensitivity of the alpha and A parameters to be studied under different chemical, physical and geometric scenarios. Simulation results show that A is a function of the calcite saturation concentration, whereas alpha depends on the spatial dimensions of the karstic network (void length and aperture). The deterministic model results were applied to real karstic systems to evaluate the geometric dimensions of submerged karstic networks. (C) 2002 Elsevier Science B.V. All rights reserved

Composite transfer functions for karst aquifers, 2003,
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Icjukic V. , Jukic D. ,
Linear transfer functions have been extensively used in hydrological studies. Generally, we support this conclusion: rainfall-runoff models based on the convolution between rainfall rates and a nonparametric transfer function (NTF) are not successful at simulating karst spring discharges during long recession periods. The tails of identified transfer functions have irregular shapes and they are not accurate physical representation of the transport through a karst system. Irregularities are the result of unavoidable errors in input and output time series and simplifications made by considering the system as linear and time invariant. This paper deals with a new form of the transfer functions for karst aquifers, the so-called composite transfer function (CTF). The CTF simulates discharges by two transfer functions adapted for the quick flow and the slow flow hydrograph component modeling. NTF is responsible for the quick flow component. The slow flow component is modeled by a parametric transfer function that is an instantaneous unit hydrograph mathematically formulated and defined from a conceptual model. By using the CTF, the irregular shape of the tail of the identified transfer function can be avoided, and the simulation of long recession periods as well as the simulation of a complete hydrograph becomes more successful. The NTF, the Nash model, the Zoch model and other similar conceptual models can be considered separately as simplified forms of the CTF. The rainfall-runoff model based on the convolution between rainfall rates and the CTF was tested on the Jadro Spring in Croatia. The results of the application are compared with the results obtained by applying NTFs independently. (C) 2003 Elsevier Science B.V. All rights reserved

Unraveling the Origin of Carbonate Platform Cyclothems in the Upper Triassic Durrenstein Formation (Dolomites, Italy), 2003,
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Preto Nereo, Hinnov Linda A. ,
Facies analysis of the Durrenstein Formation, central-eastern Dolomites, northern Italy, indicates that this unit was deposited on a carbonate ramp, as evidenced by the lack of a shelf break, slope facies, or a reef margin, together with the occurrence of a 'molechfor' biological association. Its deposition following the accumulation of rimmed carbonate platforms during the Ladinian and Early Carnian marks a major shift in growth mode of the Triassic shallow marine carbonates in the Dolomites. The Durrenstein Formation is characterized by a hierarchical cyclicity, with elements strongly suggestive of an allocyclic origin, including (a) subaerial exposure features directly above subtidal facies within meter-scale cyclothems, (b) purely subtidal carbonate cyclothems, (c) symmetric peritidal carbonate cyclothems, and (d) continuity of cyclothems of different orders through facies boundaries. The Durrenstein cyclothems are usually defined by transgressive and regressive successions, and so most of them probably originated from sea-level oscillations. Their allocyclic origin allows their use for high-resolution correlations over distances up to 30 km. A stratigraphic section in the Tre Cime di Lavaredo area, encompassing the upper part of the Durrenstein Formation and the lower part of the overlying Raibl Formation (Upper Carnian) was studied using time-frequency analysis. A strong Milankovitch signal appeared when interference arising from a variable sedimentation rate was estimated and removed by tuning the short precession line in a spectrogram. All of the principal periodicities related to the precession index and eccentricity, calculated for 220 Ma, are present: P1 (21.9 ky); P2 (17.8 ky); E1 (400 ky), E2 (95 ky), and E3 (125 ky), along with a peak at a frequency double that of the precession, which is a predicted feature of orbitally forced insolation at the equator. Components possibly related to Earth's obliquity at ca. 35 ky and ca. 46 ky are present as well. The recovery of Milankovitch periodicities allows reconstruction of a high-resolution timescale that is in good agreement with published durations of the Carnian based on radiometric ages. The recognition of a Milankovitch signal in the Durrenstein and lower Raibl formations, as well as in other Mesozoic carbonate platforms, strongly supports a deterministic and predictable--rather than stochastic--control on the formation of carbonate platforms. Carbonate platforms might thus be used in the future for the construction of an astronomical time scale for the Mesozoic

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