Middle and Lower Lunde members

Carbonate diagenesis and porosity evolution in sheet-tlood sandstones evidence from the Middle and Lower Lunde Members (Triassic) in the Snorre Field,... 

Two wells, 34/4-1 and 34/7-A-3H (Fig. 2), were selected based on the availability of coring of the Middle and Lower Lunde Members. The cored intervals from these two wells do not overlap stratigraphically. Samples examined from well 34/ 7-A-3H are exclusively sarxlstones that represent the uppermost part of the Middle Lurxle. Samples from well 34/4-1 comprise mudstones and sandstones, and represent the upper part of the Lower Lunde Member and middle and lower intervals of the Middle Lunde Member. 

The Upper Lunde Member ( 850 m thick) marks another change in the depositional facies and style of these Upper Triassic continental beds. The lower boundary of this member is usually assigned to the base of the first marked fluvial-channel sandstone. The lower part of the upper member consists of braided stream channel sandstones and units of reddish-brown floodplain mudstones characterized by palaeosols with calcrete concretions. The upper part of the member also comprises middle-sinuous stream deposits, interchanging with rather mature reddish-brown, calcrete-rich palaeosols (Nystuen Fait, 1995). 

The burial history of the Lower and Middle Lunde Members in the northeastern part of the rotated... 

Fig. 6. Cross-section of the rotated Snorre fault block showing structural position of the wells cored in the Lower and Middle Members of the Lunde Fo abon. The depth of erosion beneath the base Cretaceous unconformity (BCU) increases towards the crest line of the fault block in the northeast. The positions of chronostratigraphical boundaries are uncertain. See positions of cross-section lines on Fig. 2.

Fig. 9. Chemical composition of diagenetic carbonates from the Lower and Middle Members of Lunde Formation.

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