Möglichkeiten des Komposteinsatzes im Pflanzenbau

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Potassic lavas in the orogenic volcanism of the mediterranean area

Volcanism in the Mediterranean fold belts is dominantly related to plate-convergence processes. The occurrence of highly potassic and often leucite-bearing lavas is a typical feature of many Neogene to Quaternary volcanic provinces in the Mediterranean area.The paper describes possible relationships between the Aeolian island arc and the Roman comagmatic region and presents petrological evidence for an ultrapotassic province within the Cypriot-Taurus arc of Turkey. It is thus a contribution to the controversy about tectonic setting and geodynamic significance of the highly potassic volcanism of the Mediterranean suite.     

Carbonatitic volcanism in the Kaiserstuhl alkaline complex: Evidence for highly fluid carbonatitic melts at the earth's surface

Extrusive carbonatites are described from the Miocene alkaline complex of the Kaiserstuhl, Rhinegraben, Western Germany. Agglutinated carbonatitic lapilli form pyroclastic rocks in which all components show forms acquired when a highly fluid melt was sprayed into the air by an explosive eruption: droplets, spherical and elliptical lapilli, rods, dumbbell and pear-shaped forms.Complete morphological analogies suggest a mechanism similar to the formation of “Pele's tears”, basaltic droplets formed by the eruption of the most fluid Hawaiian basaltic magmas. Evidence is provided by this example that CaCO₃-carbonatitic magmas can exist in nature under surface conditions displaying extremely low viscosity.     

Scleractinian Corals as an Indicator of Vertical Density of the Antarctic Circumpolar Current

Oceanology - The article presents data indicating the relationship of the bathymetric distribution of solitary endemic scleractinian corals inhabiting the Antarctic continental shelf and upper...     

松辽盆地徐家围子营城组流纹岩地球化学特征及构造指示意义

松辽盆地徐家围子营城组发育一套以流纹岩为主的中酸性火山岩。岩石薄片观察和主量、微量元素研究发现,后期热液蚀变、区域埋深及低温水合作用对流纹岩的Si、K、Rb等元素含量产生一定影响; 流纹岩明显富集Rb、Th、U、Pb等强不相容元素,Ba、Sr、Ti、Eu、P 负异常,暗示其经历了斜长石、磷灰石和钛铁矿分离结晶作用。流纹岩的(⁸⁷Sr/⁸⁶Sr)_i(0.705265 ~ 0.711895)值变化范围较大,大多数ε_Nd(t)为正值(1.83 ~ 3.38),Pb同位素比值相对集中,(²⁰⁶Pb/²⁰⁴Pb)_i=18.09～18.32,(²⁰⁷Pb/²⁰⁴Pb)_i=15.50 ~ 15.54,(²⁰⁸Pb/²⁰⁴Pb)_i=37.80 ~ 38.10。研究表明,岩石的源区为大比例年轻成分与少量古老地壳的混合部分熔融,其演化过程中经历了不同程度的地壳混染。松辽盆地早白垩世火山岩为板内伸展环境喷发的产物,可能与太平洋板块俯冲导致的中国东部岩石圈减薄、软流圈上涌密切相关。     

Exploring the past through lynchet landscapes in the Vosges Mountains and the Lorraine Plateau (France)

Lynchets are ridges formed by erosion and sediment accumulation downstream of agricultural plots and offer valuable insights into past agricultural activity. These microtopographies cover vast areas and serve as indicators of historical changes in land use. As a result, their ubiquity across Europe makes them particularly interesting. In this study, we propose a geoarchaeological approach to analyze six lynchets, four in the Vosges Mountains and two on the Lorraine Plateau (France). The lynchets can be considered soil archives with no stratigraphic organization or chronological sequence from bottom to top, making it difficult to determine the age of the lynchets and identify changes in land use over time. To this end, we propose the analysis of historical and geo-historical archives combined with the “pedosedimentary” archives of lynchets through charcoal identification and dating combined with near-infrared spectroscopy to determine the age, vegetation, and past land use changes associated with lynchet landscapes. By combining these multiple data sources, we are better able to show the chronological development of these ancient agricultural systems and uncover valuable information on landscape history. Charcoal dating suggests a higher frequency of fires from the Middle Ages. The dating aligns with the regional dynamics of anthropogenic fires, indicating a potential use of fire for cultural purposes. We also demonstrate the difficulty of extrapolating the dating of a lynchet to the entire lynchet system. Our results highlight the difficulties of interpreting the formation and dating of lynchets and the lynchet system on the sole basis of charcoal analysis. However, we highlight the value of applying pedoanthracology to lynchets to determine the dynamics of land use change in former fields.