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A multidisciplinary study of the Devonian–Carboniferous boundary interval in pelagic successions of the Holy Cross Mountains and Sudetes and the ramp successions in the Western Pomerania region (Poland) is presented herein. The analysis applies the results of new palaeontological and biostratigraphic studies based mainly on conodonts, ammonoids and palynomorphs, biostratigraphic results interpreted earlier by different authors that have been re-examined, and geochemical and mineralogical characteristics, as well as magnetic susceptibility measurements across the Devonian–Carboniferous boundary interval. The study is focused on the interval from the Famennian ultimus conodont Zone to the Tournaisian duplicata conodont Zone, and from the Famennian lepidophyta–explanatus (LE) miospore Zone to the Tournaisian verrucosus–incohatus (VI) miospore Zone, respectively. The paper highlights sections, which are the most representative for the Devonian–Carboniferous boundary in each region, illustrates and summarises current knowledge on the uppermost Famennian to lowermost Tournaisian in these regions, gives data and correlation of the important stratigraphic markers for each region, and briefly correlates them outside the region. The sedimentary successions and specific phenomena, together with microscale environmental perturbations, recognised close to the Devonian/Carboniferous boundary in Poland, display a pattern similar to that observed in many areas in Europe during the Hangenberg Event.

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1 Pol ish Geo log i cal In sti tute -Na tional Re search In sti tute, Rakowiecka 4, 00-975 Warszawa, Po land Brañski, P., 2014. Cli ma tic di sas ter at the Tri as sic-Ju ras sic bound ary -a clay min er als and ma jor el e ments re cord from the Pol ish Ba sin. Geo log i cal Quar terly, 58 (2): 291-310, doi: 10.7306/gq.1161The Tri as sic-Ju ras sic bound ary in ter val (ca. 201 Ma) was a time of sud den global en vi ron men tal changes trig gered by Pangea breakup and Cen tral At lan tic Mag matic Prov ince de vel op ment. The bulk-rock min er al ogy, clay min er al ogy and major el e ment geo chem is try of 87 con ti nen tal mudrock sam ples col lected from four bore hole cores yield in for ma tion on Rhaetian-ear li est Hettangian palaeoclimatic changes in the Pol ish Ba sin. Dur ing the Rhaetian, smectite pre pon der ance was re placed by kaolinite and illite dom i na tion. This fun da men tal shift in clay min eral as sem blages (sup ported by ma jor el ement data) in di cates very sig nif i cant change in cli mate hu mid ity. More over, some beds in the Zagaje For ma tion (Up per Rhaetian-Lower Hettangian) are par tic u larly rich in kaolinite in di cat ing ex treme chem i cal weath er ing in hu mid-sub trop i cal to trop i cal cli mate ep i sodes in the af ter math of pow er ful warm ing and abun dant rain fall. Im por tantly, the first dis tinct kaolinite en rich ment ap pears al ready in the Lower Rhaetian Wielichowo Beds. In ad di tion, abrupt and ep i sodic shifts in the kaolinite-illite ra tio and in val ues of weath er ing in di ces point to pro found cli mate de sta bi li sa tion and a se quence of fre quent, cat a strophic cli ma tic re ver sals in the Late Rhaetian and at the Tri as sic-Ju ras sic bound ary. These re sults are gen er ally consis tent with car bon iso tope re cords in sec tions world wide.Key words: Tri as sic-Ju ras sic bound ary, clay min er als, ma jor el e ments, weath er ing re gime, palaeoclimatic shifts, Pol ish Ba sin.

1 Pol ish Geo log i cal In sti tute -Na tional Re search In sti tute, Rakowiecka 4, 00-975 Warszawa, Po land Brañski, P., Mikulski, S.Z., 2016. Rare earth el e ments dis tri bu tion in fine-grained de pos its from the up per most Tri as sic and Lower Ju ras sic of the Pol ish Ba sin: prov e nance and weath er ing in the source area. Geo log i cal Quar terly, 60 (2): 441-450, doi: 10.7306/gq.1288Nine teen sam ples of up per most Tri as sic and Lower Ju ras sic claystones and mudstones, which were formed in the epicontinental Pol ish Ba sin, were ana lysed by in duc tively cou pled plasma mass spec trom e try (ICP-MS) for rare earth el ements (REE) and other se lected trace el e ments (Sc, Y, Th, Zr and U). The re sults in di cate that the source of most of the claystones and mudstones stud ied were sed i men tary rocks of the up per con ti nen tal crust of old cratonic ar eas, where the protolith had a mainly fel sic char ac ter. How ever, in the lat est Tri as sic a char ac ter is tic layer formed, im ply ing sig nif i cant in put from mafic vol ca nic protolith. It was also found that mod er ately in tense chem i cal weath er ing usu ally fa voured in creased concen tra tion of the rare earths. Ex tremely strong hy dro ly sis, re lated to ep i sodes of very hot and hu mid cli mate (green house events), caused con spic u ous im pov er ish ment in REE in re sid ual clays. Weath er ing and re cy cling pro cesses mod i fied the com po si tion of REE to some ex tent, but gen er ally did not oblit er ate the orig i nal char ac ter is tics of the protolith. In some samples, en rich ment in rare earth el e ments was ob served, caused by ad mix tures of ac ces sory min er als (be ing a main car rier of REE) and/or in creased sort ing dur ing re cy cling. Key words: rare earth el e ments, prov e nance, palaeo-weath er ing, up per most Tri as sic and Lower Ju ras sic, Pol ish Ba sin.

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Fine-grained siliciclastic rocks from the Triassic-Jurassic transition (Rhaetian–Hettangian) in the former Mid-Polish Trough were the subject of the geochemical study at the Polish Geological Institute – National Research Institute in Warsaw. Ninety-four samples of claystones and mudstones from six archived drill cores were analysed by ICP-MS and XRF for rare earth elements (REE) and other trace elements. The results indicate that the sources of most of the claystones and mudstones were sedimentary rocks of the upper continental crust of old cratonic areas, where the protolith had a moderately felsic character. Weathering and recycling processes modified the original chemical composition to some extent. However, during Rhaetian and early Hettangian, some geochemical data in the south-eastern segment of the MPT suggest significant input from a mafic volcanic protolith. Moreover, a clear enrichment in rare-earth elements was observed in few samples, caused by admixtures of accessory minerals (being a main carrier of REE). Nevertheless, based on currently obtained data, the Rhaetian–Hettangian concentrations of REE (and other trace elements) in the MPT are low and they are of scientific indicative significance, not of raw material importance.