Home Geologische Onderzoeken Stratigraphy Introduction

The Berg en Terblijt hardground is a unique layer, because of the many fossils with a very good preservation state found in there. On top of this hardground a bioclast grit layer was deposited. The top of the Berg en Terblijt hardground is probably the Cretaceous/ Tertiary boundary (K/T) (Vonhof & Smit, 1996), although some research results do not support that (Smit & Brinkhuis, 1996).

The purpose of the fieldwork carried out in the Curfs quarry in Berg en Terblijt was to determine the relation between the Berg en Terblijt hardground, the bioclast grit layers on top, the clay layers, and the K/T boundary. There are several hypotheses about the forming of the Berg en Terblijt hardground. First, the hardground is a normal hardground like the other hardgrounds in the Meerssen member. The second hypothesis is from Zijlstra, 1996, and comprises the deposition of a stormlayer over the hardground and thus preserving the fossils present. The third hypothesis is also the deposition of a storm layer on top of the hardground, but now as a result of the Chicxulub meteorite impact in the Gulf of Mexico at the end of the Cretaceous period.

To test the hypotheses, seven sections were sampled, measured, and correlated in the Curfs quarry from several meters below the "Berg en Terblijt" hardground until the Vroenhoven horizon above if possible. To compare the bioclast grit layer and hardground to a 'normal' sequence, four sections were measured in the Meerssen member in the ENCI quarry. The grainsize, roundness, sedimentary structures, and the mesofossil content of the sequences from both locations were compared.

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