Title: Lacustrine microporous micrites of the Madrid Basin (Late Miocene, Spain) as analogues for shallow-marine carbonates of the Mishrif reservoir Formation (Cenomanian to Early Turonian, Middle East)
Authors: Volery, Chadia ×
Davaud, Eric
Foubert, Anneleen
Caline, Bruno #
Issue Date: 2010
Publisher: Institut für Paläontologie der Universität Erlangen-Nürnberg
Series Title: Facies vol:56 pages:385-397
Abstract: Shallow-marine microporous limestones
account for many carbonate reservoirs. Their formation,
however, remains poorly understood. Due to the lack of
recent appropriate marine analogues, this study uses a
lacustrine counterpart to examine the diagenetic processes
controlling the development of intercrystalline microporosity.
Late Miocene lacustrine microporous micrites of the
Madrid Basin (Spain) have a similar matrix microfabric as
Cenomanian to Early Turonian shallow-marine carbonates
of the Mishrif reservoir Formation (Middle East). The
primary mineralogy of the precursor mud partly explains
this resemblance: low-Mg calcites were the main carbonate
precipitates in the Cretaceous seawater and in Late
Miocene freshwater lakes of the Madrid Basin. Based on
hardness and petrophysical properties, two main facies
were identified in the lacustrine limestones: a tight facies
and a microporous facies. The tight facies evidences strong
compaction, whereas the microporous facies does not.
The petrotexture, the sedimentological content, and the
mineralogical and chemical compositions are identical in
both facies. The only difference lies in the presence of
calcite overgrowths: they are pervasive in microporous
limestones, but almost absent in tight carbonates. Early
diagenetic transformations of the sediment inside a fluctuating
meteoric phreatic lens are the best explanation for
calcite overgrowths precipitation. Inside the lens, the dissolution
of the smallest crystals in favor of overgrowths on
the largest ones rigidifies the sediment and prevents compaction,
while partly preserving the primary microporous
network. Two factors appear essential in the genesis of
microporous micrites: a precursor mud mostly composed of
low-Mg calcite crystals and an early diagenesis rigidifying
the microcrystalline framework prior to burial.
ISSN: 0172-9179
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Division of Geology
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
10473.pdf Published 1233KbAdobe PDFView/Open Request a copy

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science