Metasomatic origin of garnet xenocrysts from the V. Grib kimberlite pipe, Arkhangelsk region, NW Russia

AbstractThis paper presents new major and trace element data from 150 garnet xenocrysts from the V. Grib kimberlite pipe located in the central part of the Arkhangelsk diamondiferous province (ADP). Based on the concentrations of Cr2O3, CaO, TiO2 and rare earth elements (REE) the garnets were divided into seven groups: (1) lherzolitic “depleted” garnets (“Lz 1”), (2) lherzolitic garnets with normal REE patterns (“Lz 2”), (3) lherzolitic garnets with weakly sinusoidal REE patterns (“Lz 3”), (4) lherzolitic garnets with strongly sinusoidal REE patterns (“Lz 4”), (5) harzburgitic garnets with sinusoidal REE patterns (“Hz”), (6) wehrlitic garnets with weakly sinusoidal REE patterns (“W”), (7) garnets of megacryst paragenesis with normal REE patterns (“Meg”). Detailed mineralogical and geochemical garnet studies and modeling results suggest several stages of mantle metasomatism influenced by carbonatite and silicate melts. Carbonatitic metasomatism at the first stage resulted in refertilization of the lithospheric mantle, which is evidenced by a nearly vertical CaO-Cr2O3 trend from harzburgitic (“Hz”) to lherzolitic (“Lz 4”) garnet composition. Harzburgitic garnets (“Hz”) have probably been formed by interactions between carbonatite melts and exsolved garnets in high-degree melt extraction residues. At the second stage of metasomatism, garnets with weakly sinusoidal REE patterns (“Lz 3”, “W”) were affected by a silicate melt possessing a REE composition similar to that of ADP alkaline mica-poor picrites. At the last stage, the garnets interacted with basaltic melts, which resulted in the decrease CaO-Cr2O3 trend of “Lz 2” garnet composition. Cr-poor garnets of megacryst paragenesis (“Meg”) could crystallize directly from the silicate melt which has a REE composition close to that of ADP alkaline mica-poor picrites. P-T estimates of the garnet xenocrysts indicate that the interval of ∼60–110 km of the lithospheric mantle beneath the V. Grib pipe was predominantly affected by the silicate melts, whereas the lithospheric mantle deeper than 150 km was influenced by the carbonatite melts

Раннее назначение генно-инженерных биологических препаратов при иммуновоспалительных заболеваниях: возможности и перспективы. Позиция экспертов

Psoriasis (Ps), psoriatic arthritis (PsA), and inflammatory bowel diseases (IBDs) are characterized by a  progressive course and commonly result in disability. Therefore, their early diagnosis with the assessment of a  clinical phenotype and unfavorable prognostic factors and the timely initiation of therapy are important. The paper provides the expert consensus on the definition of the early stage of Ps, PsA, and IBDs, their treatment goals and main unfavorable prognostic factors. It also gives the rationale for the early use of biological agents in patients with immune-mediated inflammatory diseases.Псориаз (Пс), псориатический артрит (ПсА) и  воспалительные заболевания кишечника (ВЗК) характеризуются прогрессирующим течением и  нередко приводят к  инвалидизации, поэтому важными задачами становятся их ранняя диагностика с  оценкой клинического фенотипа и  факторов неблагоприятного прогноза и  своевременное начало терапии. В  статье приводятся согласованная позиция экспертов по определению ранней стадии Пс, ПсА и  ВЗК, цели терапии и  основные факторы неблагоприятного прогноза течения этих заболеваний, представлено обоснование раннего применения генно-инженерных биологических препаратов у  пациентов с  иммуновоспалительной патологией