Utwory kenozoiku w nadkładzie złóż soli w regionie Zatoki Puckiej
Abstract
Cenozoic overburden of salt rocks deposits in the Puck Bay region
A b s t r a c t . Thick succession of Cenozoic sediments occurs in the overburden of the salt rock deposits in the Puck Bay region. It starts with Middle Eocene/Lower Oligocene marine to brackish sediments. Marine clayey-silty deposits of the Pomerania Fm. rest on the pre-Cenozoic basement consisting of various Upper Cretaceous units and situated at 90–110 m b.s.l. A transgressive sequence with basal horizon of gravels and phosphatic nodules is succeeded by silty amber-bearing Połczyno Fm. and sandy Chłapowo Fm of the upper marine complex. The early Oligocene brackish deposits (Czempin Fm.) and the uppermost level of the Upper Mosina Fm. sands reflect the Late Rupelian marine ingression. Miocene deposits, defined mostly as Middle Miocene in age, consist of sands, silts and clays, locally with one to a few lignite layers. Their exposures occur along the cliff shores of the moraine uplands. Total Palaeogene/Neogene thickness is up to 50 m. Quaternary deposits of the Meso- and Neopleistocene cover erosional-exarational Neogene surface. They are built of three to four glacial till layers with intra-moraine sediments. Large denivelations between the Quaternary bottom surface and the recent soil surface are the result of subglacial erosion processes. Infilling of the soil-surface depressions with alluvial and phytogenic matter as well as marine abrasion and accumulation of the Littorina sea sediments took place in the Holocene. Most probably this was also the time of origin of the Hel Spit (with the largest thickness of the Holocene in the whole Poland, that is about 100 m) and flooding surrounding low coastal areas by the recent Puck Bay waters.
A b s t r a c t . Thick succession of Cenozoic sediments occurs in the overburden of the salt rock deposits in the Puck Bay region. It starts with Middle Eocene/Lower Oligocene marine to brackish sediments. Marine clayey-silty deposits of the Pomerania Fm. rest on the pre-Cenozoic basement consisting of various Upper Cretaceous units and situated at 90–110 m b.s.l. A transgressive sequence with basal horizon of gravels and phosphatic nodules is succeeded by silty amber-bearing Połczyno Fm. and sandy Chłapowo Fm of the upper marine complex. The early Oligocene brackish deposits (Czempin Fm.) and the uppermost level of the Upper Mosina Fm. sands reflect the Late Rupelian marine ingression. Miocene deposits, defined mostly as Middle Miocene in age, consist of sands, silts and clays, locally with one to a few lignite layers. Their exposures occur along the cliff shores of the moraine uplands. Total Palaeogene/Neogene thickness is up to 50 m. Quaternary deposits of the Meso- and Neopleistocene cover erosional-exarational Neogene surface. They are built of three to four glacial till layers with intra-moraine sediments. Large denivelations between the Quaternary bottom surface and the recent soil surface are the result of subglacial erosion processes. Infilling of the soil-surface depressions with alluvial and phytogenic matter as well as marine abrasion and accumulation of the Littorina sea sediments took place in the Holocene. Most probably this was also the time of origin of the Hel Spit (with the largest thickness of the Holocene in the whole Poland, that is about 100 m) and flooding surrounding low coastal areas by the recent Puck Bay waters.