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Systemy piętrowych nor krewetek-alfeuszy i ich znaczenie środowiskowe w oksfordzie i kimerydzie Gór Świętokrzyskich

Radwańska U., Radwański A.

Volumina Jurassica

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2004

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Vol. 2, no. 1

113-130

EN

To the activity of alpheid shrimps genus Alpheus Weber, 1795) ascribed are the tiered burrows of a gridlike appearance from Lower Kimmeridgian oolitic shoals and Middle Oxfordian nearshore micritic limestones of the Holy Cross Mountains, Central Poland. The burrow networks are confined to beds of the soft or hard bottom type, the upper parts of which are more or less deeply truncated, to indicate erosional events of storm agitation. At low stand, the open burrows served as traps for solutions derived from the nearby hypersaline lagoons of the sabkha type, to cause precipitation either of dolomite, or of silica gel. At high stand, the open burrows, exemplified by the Małogoszcz section (Lower Kimmeridgian), became taphonomic traps and/or crevice habitats for diverse biota, the echinoderms in particular, to form their graveyards (EchinodermenlagerstŹtten). In these, represented are echinoids (tests, some spine-coated, all either empty, or sediment-filled; broken tests and their fragments, spines) stalkless crinoids (cusps, centrodorsals, radials, brachials, cirrals), stalked crinoids (columnals, pluricolumnals), starfish (marginalia, ambulacral plates), and ophiuroids (vertebrae, arm plates). Eco-taphonomic pathways for particular echinoderms (21 taxa taxonomically recognised) are interpreted since their death to burial in open burrows. Spine-coated echinoids were entrapped alive, others were swept into during successive storms which acted as a lethal agent. The storms, catastrophic for echinoderm communities, have prevailed through a longer timespan, when the alpheid-burrowed shoal evolved from the soft bottom to the hard ground colonized by a successive echinoderm community dominated by stalked crinoids.

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Jeżowce oksfordu Bałtowa

Radwańska U.

Volumina Jurassica

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2004

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Vol. 2, no. 1

131-140

EN

The autecology of echinoids from the Middle Oxfordian coraliferous limestones of Bałtów (NW margin of the Holy Cross Mountains, Central Poland) is discussed, as aparent from the morphology of tests, ambulacral pores for tube feet, and spines. Inferred is mode of life, locomotion, and feeding, as well as the diet of the taxonomically recognised three species: Paracidaris florigemma (Phillips, 1829) – spines only, Glypticus hieroglyphicus (Goldfuss, 1826), and Hemicidaris merryaca Cotteau, 1850, the latter reported for the first time in Poland. The phenotypic convergence is indicated of such species as: P. florigemma and extant Eucidaris tribuloides Desmoulins, 1835, of Florida and the Caribbean, as well as G. hieroglyphicus and extant Colobocentrotus atratus (Linnaeus, 1758) of the Indo-Pacific. Environmental conditions, under which the Bałtów echinoids lived, are concluded as extremely shallow marine (shallow subtidal up to low-intertidal), connected with the Bałtów coral patch reef nearby.

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Dynamika rozwoju utworów koralowych środkowego oksfordu okolic Bałtowa

Gutowski P.

Volumina Jurassica

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2004

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Vol. 2, no. 1

17-28

EN

Coral facies developed on the Middle Oxfordian carbonate ramp were controlled in the region of Bałtów, NE margin of the Holy Cross Mts., Poland, by syndepositional activity of extensional fault blocks. Elevated parts of sea bottom were occupied since Early Oxfordian time by sponge bioherms successively colonized by coral reefs when grown up to the sea level. Micritic sedimentation prevailed in interbioherm denivelations. This micritic succession was replaced by soft-bottom coral buildups constructed by flat coral colonies, typical of a relatively quiet environment of the depths 20-70 m, and finally by coarse bioclastic grainstones and oncolites which are interpreted as talus of the coral reef constructed on tops of former sponge bioherms by branched and hemispherical coral colonies in very dynamic and extremely shallow water conditions.