Charles Lyell from 1832 to 1835: marriage, Principles, 2 trips to Heidelberg, snails and loess

Charles Lyell, on his way to becoming a famous geologist, married Mary Horner in Bonn in July 1832; volume 3 of his ‘Principles of Geology’ was published by John Murray in London in May 1833. Between these two dates Lyell encountered the loess of the Rhine valley. The loess impressed Lyell and he included mentions of it in the Principles, first in 1833 and then, with some revised ideas, in volume 4 of the 4th edition published in 1835. Twelve editions of the Principles were published between 1830 and 1875 and it became one of the most important works in the development of geology, and made a major contribution to the worldwide spread of loess awareness. It is possible that Lyell was drawn to the loess because of its high molluscan content, he was particularly attracted to the study of shells.     

Effect of plant growth on Pb and Zn geoaccumulation in 300-year-old mine tailings of Zacatecas,México

Concentrations of Pb and Zn, plant uptake of these metals, the influence of the plants’ growth on the physicochemical properties and metal concentrations in the tailings of an abandoned 300-year-old mine tailing dam in Zacatecas, Mexico were investigated. Tailings were found to be heavily contaminated, with average levels of 2621 ± 53 and 3827 ± 83 mg/kg for Pb and Zn, respectively (maximum concentrations of 8466 ± 116 and 12,475 ± 324 mg/kg, respectively), exceeding international standards. Though physico-chemical conditions (pH, conductivity, redox potential, moisture, organic matter, nitrate, nitrite, ammonium nitrogen, total nitrogen, phosphorus and sulfates) do not favor the development of vegetation, some plants have adapted to these adverse conditions. Moreover, there was a significant reduction of Pb and Zn concentration in the rhizosphere (between 10–78% for Pb and 18–62% for Zn, depending on plant species). Sporobolus airoides showed average biomass concentrations of 173 ± 2 and 313 ± 6 mg/kg, for Pb and Zn, respectively; which implies a risk for mobility and possible incorporation into the food chain. Barcleyanthus salicifolius, Asclepsias linaria and Cortaderia selloana on the other hand, showed average biomass concentrations of 28 ± 3 and 121 ± 5 mg/kg of Pb and Zn, respectively, thus representing a lower biomagnification risk. The effect of these plants to reduce metal concentrations in the rhizosphere, improve physico-chemical conditions in metal polluted substrates, but with limited metal accumulation in biomass, suggests that they can be evaluated for use in stabilizing metal polluted tailings.     

The mechanism and kinetics of DTPA-promoted dissolution of barite

The dissolution rate of natural barite, BaSO₄, was measured in solutions of DTPA (diethylene triamine penta-acetic acid) to investigate the mechanism of ligand-promoted dissolution using a strong chelating agent. Experiments were carried out over a range of DTPA concentrations 0.5–0.0001 M solutions, at room temperature (22 °C), as well as a range of temperatures, 22–80 °C at 1 atm. The dissolution rate is inversely related to the DTPA concentration in solution. A more dilute DTPA solution is shown to be more efficient as a solvent in terms of the approach to the equilibrium saturation value for the dissolution of Ba²⁺. An analysis of the temperature dependence of the dissolution rate at high pH by the determination of activation energies indicates that the reaction is probably controlled by the pre-exponential term in the rate constant. This indicates that reaction frequency mostly controls differences in reactivity and suggests an explanation for the results in terms of stearic hindrance due to adsorbed DTPA molecules at the barite surface. The effect of DTPA on the solvation of the Ba²⁺ ion may also influence the dissolution rate.     

Anthropogenic changes in the sediment composition of Lake Gości& aogon;ż (central Poland), during the last 330 yrs*

According to historical sources, the development of settlement around Lake Goci& aogon; during the last 330 yrs was intense at two time periods: the second half of the 1700's, and from ca. 1880 until 1944. The small farms were then abandoned, following which the lake surroundings were planted with forest trees. The presented study of human influence on the lake ecosystem and surrounding vegetation has been based on analyses of general sediment composition and its chemistry, pollen, Cyanobacteria, Chlorophyceae, Rotatoria, Cladocera, and a preliminary diatom survey. The history of human impact has been divided into four phases: 1. Phase of small local hamlets (before ca. 1770): The human impact was rather moderate then, but the cultivation of Canabis sativa, Secale cereale and later of Fagopyrum is evidenced from that time. 2. Phase of Hollandii settlement (ca. 1770-1863). Its influence is indicated first by the recession of deciduous wood (Corylus, Carpinus) stands, which triggered drastic drop of calcium in sediments. The development of rural economy in the area, including, an extension of agriculture (Secale and other cereals, crucifers, potatoes), and animal breeding based partly on grazing in the forest, is evidenced only after 1820. 3. Phase of German colonization (1863-1944): In the early periods (before 1910) the pollen spectra do not document any essential change in the type of farming, however, a serious disturbance of the lake ecosystem and sediment chemistry is evidenced by the blooms of Araphidinae diatoms and Tetraedron minimum, a maximum frequency of Bosmina longirostris, disturbances of the regular spring blooms of Chrysophyceae, appearance of vivianite, distinct maxima of organic matter, potassium, and iron concentration in sediments and an increase of the sedimentation rate. An intensification of agricultural activities commenced around 1910; woods, including also pinewoods, were then heavily devastated, and farming extended on poor soils, what was symptomatic for the general poverty of population. Coincidently in the lake, Centriceae showed blooms, Araphidinae diatoms and Tetraedron minimum developed, and the content of potassium, iron and phosphorus increased substantially, indicating altogether rising eutrophication. 4. Phase of restoration of the natural landscape (after 1945): The farm degradation from ca. 1944 is very weakly expressed in pollen data, which show a substantial fall of farming indicators from 1953/6 only, when the whole area was used for forest plantation. It was accompanied by a certainly spontaneous development of Betula and Alnus woods, this process progressing till recent time. The gradual extinction of farming activity near Lake Goci was accompanied by abrupt changes in the lake ecosystem, expressed by the restored blooms of Chrysophyceae expansion of planktonic Cladocera, rapid decline of phosphorus and extinction of vivianite from sediments. As documented by the drop of Cu/Zn ratio, lake hypolimnion has been weakly oxidized since 1949, what was probably responsible for the drop of Fe and Mn content in sediments. Increasing strength of overturns affected preservation of laminae in sediments, which almost completely disappeared after 1966.     

Paleomagnetism and magnetic mineralogy of metabasites and granulites from Orlica-Śnieżnik Dome (Central Sudetes)

The results of palaeomagnetic, rock magnetic, and microscopic study of Early Paleozoic metabasites and granulites from the Orlica?nie?nik Dome (OSD, Sudetes) have been combined with geochronological data. In the eastern part of the OSD (?nie?nik Massif, SM) ferrimagnetic pyrrhotite is prevalent, accompanied by various amounts of Fe-oxides. In the western part of the OSD (Orlica-Bystrzyca Massif, OBM) Fe-oxides dominate. All magnetic minerals originated during hydrothermal and weathering processes. The palaeomagnetic study revealed the presence of three secondary components of natural remanence: Late Carboniferous, Late Permian, and Mesozoic. Two Paleozoic components are related to volcanic activity in the Sudetes. They are carried by pyrrhotite and Fe-oxides and were isolated only in SM rocks. The Mesozoic component was determined in both parts of the OSD and is carried by Fe-oxides. It covers a time span, from ～160 to ～40 Ma, corresponding to a long period of alteration.     

Crustal memory and basin evolution in the Central European Basin System—new insights from a 3D structural model

The Central European Basin System (CEBS) is composed of a series of subbasins, the largest of which are (1) the Norwegian–Danish Basin (2), the North German Basin extending westward into the southern North Sea and (3) the Polish Basin. A 3D structural model of the CEBS is presented, which integrates the thickness of the crust below the Permian and five layers representing the Permian–Cenozoic sediments. Structural interpretations derived from the 3D model and from backstripping are discussed with respect to published seismic data. The analysis of structural relationships across the CEBS suggests that basin evolution was controlled to a large degree by the presence of major zones of crustal weakness. The NW–SE-striking Tornquist Zone, the Ringkøbing-Fyn High (RFH) and the Elbe Fault System (EFS) provided the borders for the large Permo–Mesozoic basins, which developed along axes parallel to these fault systems. The Tornquist Zone, as the most prominent of these zones, limited the area affected by Permian–Cenozoic subsidence to the north. Movements along the Tornquist Zone, the margins of the Ringkøbing-Fyn High and the Elbe Fault System could have influenced basin initiation. Thermal destabilization of the crust between the major NW–SE-striking fault systems, however, was a second factor controlling the initiation and subsidence in the Permo–Mesozoic basins. In the Triassic, a change of the regional stress field caused the formation of large grabens (Central Graben, Horn Graben, Glückstadt Graben) perpendicular to the Tornquist Zone, the Ringkøbing-Fyn High and the Elbe Fault System. The resulting subsidence pattern can be explained by a superposition of declining thermal subsidence and regional extension. This led to a dissection of the Ringkøbing-Fyn High, resulting in offsets of the older NW–SE elements by the younger N–S elements. In the Late Cretaceous, the NW–SE elements were reactivated during compression, the direction of which was such that it did not favour inversion of N–S elements. A distinct change in subsidence controlling factors led to a shift of the main depocentre to the central North Sea in the Cenozoic. In this last phase, N–S-striking structures in the North Sea and NW–SE-striking structures in The Netherlands are reactivated as subsidence areas which are in line with the direction of present maximum compression. The Moho topography below the CEBS varies over a wide range. Below the N–S-trending Cenozoic depocentre in the North Sea, the crust is only 20 km thick compared to about 30 km below the largest part of the CEBS. The crust is up to 40 km thick below the Ringkøbing-Fyn High and up to 45 km along the Teisseyre–Tornquist Zone. Crustal thickness gradients are present across the Tornquist Zone and across the borders of the Ringkøbing-Fyn High but not across the Elbe Fault System. The N–S-striking structural elements are generally underlain by a thinner crust than the other parts of the CEBS.The main fault systems in the Permian to Cenozoic sediment fill of the CEBS are located above zones in the deeper crust across which a change in geophysical properties as P-wave velocities or gravimetric response is observed. This indicates that these structures served as templates in the crustal memory and that the prerift configuration of the continental crust is a major controlling factor for the subsequent basin evolution.     

3D structural model of the Polish Basin

A 3D structural modelling of the Permian–Mesozoic Polish Basin was performed in order to understand its structural and sedimentary evolution, which led to basin maturation (Permian–Cretaceous) and its tectonic inversion (Late Cretaceous–Paleogene). The model is built on the present-day structure of the basin and comprises 13 horizons within the Permian to Quaternary rocks. The analysis is based on 3D depth views and thickness maps. The results image the basin-scale symmetry, the perennial localization of the NW–SE-oriented basin axis, the salt movements due to tectonics and/or burial, and the transverse segmentation of the Polish Basin. From these observations, we deduce that salt structures are correlated to the main faults and tectonic events. From the model analysis, we interpret the stress conditions, the timing, and the geometry of the tectonic inversion of the Polish Basin into a NW–SE-oriented central horst (Mid-Polish Swell) bordered by two lateral troughs. Emphasis is placed on the Zechstein salt, considering its movements during the Mesozoic sedimentation and its decoupling effect during the tectonic inversion. Moreover, we point to the structural control of the Paleozoic basement and the crustal architecture (Teisseyre–Tornquist Zone) on the geometry of the Polish Basin and the Mid-Polish Swell.     

Basin evolution of the northern part of the Northeast German Basin — Insights from a 3D structural model

A 3D structural model for the entire southwestern Baltic Sea and the adjacent onshore areas was created with the purpose to analyse the structural framework and the sediment distribution in the area. The model was compiled with information from several geological time-isochore maps and digital depth maps from the area and consists of six post-Rotliegend successions: The Upper Permian Zechstein; Lower Triassic; Middle Triassic; Upper Triassic–Jurassic; Cretaceous and Cenozoic. This structural model was the basis for a 3D backstripping approach, considering salt flow as a consequence of spatially changing overburden load distribution, isostatic rebound and sedimentary compaction for each backstripping step in order to reconstruct the subsidence history in the region. This method allows determination of the amount of tectonic subsidence or uplifting as a consequence of the regional stress field acting on the basin and was followed by a correlation with periods of active salt movement. In general, the successions above the highly deformed Zechstein evaporites reveal a thickening trend towards the Glückstadt Graben, which also experienced the highest amount of tectonic subsidence during the Mesozoic and Cenozoic. Two periods of accelerating salt movement in the area has been correlated with the E–W directed extension during the Late Triassic–Early Jurassic and later by the Late Cretaceous–Early Cenozoic inversion, suggesting that the regional stress field plays a key role in halokinesis. The final part of this work dealt with a neotectonic forward modelling in an attempt to predict the future topography when the system is in a tectonic equilibrium. The result reveals that many of the salt structures in the region are still active and that future coastline will run with a WNW–ESE trend, arguing that the compressional stresses related to the Alpine collision are the prime factor for the present-day landscape evolution.     

Topotactic formation of ferrisicklerite from natural triphylite under hydrothermal conditions

The topotactic oxidation and delithiation reaction from triphylite, Li(Fe,Mn)PO₄, leading to ferrisicklerite, Li_<1(Fe³⁺,Mn²⁺)PO₄, was investigated under hydrothermal conditions. A cuboid cut from a triphylite single-crystal (Palermo Mine, New Hampshire, USA) with the composition Li_0.93(3)(Fe²⁺ _0.733(6),Fe³⁺ _0.015(1),Mn²⁺ _0.210(4),Mg_0.063(2))_1.021(8)P_1.00(2)O₄ in addition with ground bulk material were treated with KMnO₄ and 30 % H₂O₂(aq) as oxidizing agent in a 0.1 N hydrochloric acid solution in the temperature range between 60 and 200 °C. At 120 °C a rim of 0.1 mm thickness of ferrisicklerite had formed around the core of unreacted triphylite. The sharp reaction boundary was clearly visible, due to the reddish brown absorption colors of ferrisicklerite, compared to colorless triphylite. Using single-crystal X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), electron probe micro-analysis (EPMA) and ⁵⁷Fe-Mössbauer spectroscopy the product ferrisicklerite was characterized and its composition determined as Li_0.30(7)(Fe²⁺ _0.049(1)Fe³⁺ _0.65(2)Mn²⁺ _0.218(5)Mg_0.062(2))_0.98(1)P_1.01(3)O₄, with unit cell parameters a?=?4.795(1), b?=?9.992(4), and c?=?5.886(2) Å. EPMA investigations across the reaction boundary showed no changes in the concentrations of Fe, Mn, Mg, and P. In contrast, SIMS measurements clearly proved the delithiated state of the ferrisicklerite product. Polarization microscopy revealed that the orientation of the ferrisicklerite rim was the same as that of the original triphylite single-crystal, confirming the strictly topotactic character of the reaction.