About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


AAPG Bulletin, V. 86, No. 9 (September 2002), P. 1573-1591.

Copyright ©2002. The American Association of Petroleum Geologists. All rights reserved.

Diagenesis associated with cooling during burial: An example from Lower Cretaceous reservoir sandstones (Sirt basin, Libya)

A. Ceriani,1 A. Di Giulio,2 R. H. Goldstein,3 C. Rossi4

1Dipartimento di Scienze della Terra, Universitae di Pavia, Pavia, Italy, 27100; email: [email protected]
2Dipartimento di Scienze della Terra, Universitae di Pavia, Pavia, Italy, 27100; email: [email protected]
3University of Kansas, Department of Geology, 1475 Jayhawk Boulevard, Room 120, Lawrence, Kansas, 66045-7613; email: [email protected]
4Departamento de Petrologia y Geoquimica, Facultad de Ciencias Geologicas, Universidad Complutense, Madrid, 28040, Spain; email: [email protected]


Andrea Ceriani is a postdoctoral student at the University of Pavia (Italy). He received his M.S. degree (1995) and Ph.D. (2001) from the University of Pavia. His current research includes diagenesis of carbonates and siliciclastics, with particular attention to fluid-inclusions studies, and provenance of modern sands and ancient arenites.

Andrea Di Giulio is associate professor at the University of Pavia (Italy). He received his B.Sc. degree in geological science in 1985 and then began his research, focusing mostly on the sedimentology and petrology of clastic sequences. His current interests include diagenesis of reservoir rocks, modeling of foredeep basins, and models to relate source land geology, climate, and relief to the composition of so-called daughter sediments.

Robert H. Goldstein is the Haas Distinguished Professor at the University of Kansas. He received his B.S. degree from Juniata College, Huntingdon, Pennsylvania, and his M.S. degree and Ph.D. from the University of Wisconsin. His current research includes development of the fluid-inclusion tool for diagenetic research, integration of diagenesis with sequence stratigraphy and tectonic setting, and evaluation of controls on the sequence stratigraphic character of carbonate rocks.

Carlos Rossi is an associate professor in the Department of Petrology and Geochemistry at Complutense University (Madrid). He received a Ph.D. in geology from Complutense University in 1993. His main research interests are sequence stratigraphy and diagenesis of carbonates, Quaternary karst, and diagenesis of sandstone petroleum reservoirs, especially from north Africa.


Shirley P. Dutton and David W. Houseknecht are kindly acknowledged for their careful reviews. Financial grants were provided by the Italian Ministry of University and Research (MURST), Pavia University funds (FAR), and Andrea Ceriani's personal funds (Progetto Giovani Ricercatori 1999).


Fluid inclusions in quartz and dolomite cements were used to determine temperature, timing, origin, and function of fluids in the diagenetic evolution of the Lower Cretaceous Upper Sarir Sandstone (Sirt basin, Libya). Transmitted light, backscattered electron, and scanning electron microscope (SEM) cathodoluminescence analyses were carried out to determine the paragenesis.

In quartz overgrowths, fluid inclusions along the grain-overgrowth boundary yield homogenization temperatures from 130 to 141 degreesC and salinities between seawater and freshwater. Aqueous fluid inclusions in later quartz overgrowths have homogenization temperatures from 114 to 129 degreesC and salinities between 18 and 21 wt. % NaCl equivalent. Fluid inclusions in dolomite have variable homogenization temperatures (120-141 degreesC) and high salinities (20-22 wt. % NaCl equivalent).

This trend in homogenization temperatures of fluid inclusions is interpreted as the result of quartz cement precipitation in the presence of hot, low-salinity, connate fluids connected with an increased heat flow related to regional rifting. Later quartz overgrowths precipitated during regional cooling concurrent with the end of the rifting and after invasion of saline fluids, possibly brought in from adjacent areas or refluxed downward during or after times of evaporite deposition.

This diagenetic history linked to a decreasing heat flow could be common in other aborted-rift basins, which are important targets for oil exploration.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].