- Tytuł:
- Stable isotope composition of carbonates in loess at the Carpathian margin (SE Poland)
- Autorzy:
-
Łącka, Bożena
Łanczont, Maria
Komar, Maryna
Madeyska, Teresa - Powiązania:
- https://bibliotekanauki.pl/articles/2026059.pdf
- Data publikacji:
- 2008
- Wydawca:
- Polska Akademia Nauk. Czytelnia Czasopism PAN
- Tematy:
-
loess
authigenic carbonates
carbon and oxygen stable isotopes
Vistulian - Opis:
- Sam ples for the study were col lected from, known from the lit era ture, out crop pro files in Zar zecze, Ra dymno, Dybawka, Tarnawce and Pikulice- Nehrybka, situ ated at the Car pa thian bor der, in the vi cin ity of the Prze myoel town, close to the San River val ley (SE Po land). They rep re sent the Vis tulian loess- palaeosol se quences. Car bon ates oc cur mainly in the lo esses rep re sent ing OIS 2 and 3. Pol len analy sis, car ried out for two pro files (Tarnawce, Ra dymno), throws light on pa laeoe co logi cal con di tions of loess cover for ma tion and trans for ma tion. Iso topic analy sis of authigenic car bon ates was car ried out on car bon ate ce mented bod ies dis persed through out the loess in forms of nod ule, rhi zolith and rhi zo cre tion and on bio clasts, mainly snail shells, os tra cod valves, and sparse glob ules (proba bly the in ter nal shells of the na ked snails). In the suc ces sions stud ied, the up per Vistulian loess de pos ited in en vi ron ment with poor veg e ta tion, con tains rhizoliths and rhizocretions mainly, while in the mid dle and lower Vistulian loess with well de vel oped soils, gley ho ri zons, and in ter ca la tions of sub aque ous sed i ments, re mains of snail shells and ostracod valves pre vail. The two main forms of car bon ates dif fer mark edly in iso to pic com po si tion from one an other. These dif fer ences seem to be more im por tant than those be tween sam ples of one form of car bon ates along par tic u lar sec tions. That is the re sult of nu mer ous fac tors af fect ing the frac tion ation of car bon and, in par tic u lar, ox y gen sta ble iso topes in the en vi ron ment of pre cip i ta tion of authigenic cal cite. The iso to pic com po si tion of car bon ates ce ment ing sed i ments is con trolled mainly by biomineralization of or ganic mat ter and lo cal cli ma tic pa ram e ters which were rather slightly dif fer en ti ated dur ing the for ma tion of the stud ied sed i ments. The d13C val ues for bioclasts vary in a broader range than for calcitic ce ments. Usu ally the snail shell car bon ate is more en riched with heavier car bon iso tope than that from ostracod valves, re sult ing from the iso to pic equi lib rium with pre cip i ta tion and with sur face wa ters, re spec tively. Bas ing on our study we can con clude that fluc tu a tions of iso tope com po si tion of authigenic car bon ates make it hard to ap ply as a paleoclimatic in di ca tor. How - ever, the gen eral trend of d18O vari a tion in ana lysed car bon ate frac tions from leoss-palaeosol se quences dis plays some con nec tions with cli ma tic fluc tu a tions.
- Źródło:
-
Studia Quaternaria; 2008, 25; 3-21
1641-5558
2300-0384 - Pojawia się w:
- Studia Quaternaria
- Dostawca treści:
- Biblioteka Nauki
Artykuł