RT Journal Article
T1 Grain size, composition, porosity and permeability contrasts within cross-beddedsandstones in Tertiary fluvial deposits, central Spain
A1 Hartkamp, Christel A.
A1 Arribas Mocoroa, José
A1 Tortosa, A.
AB Permeability measured with a portable probe pcrmcflmeter on outcrops of cross·bcdded sandstones rangesbetwecn 0·9 and 19 O. The highest pcrmeability (2-19 0 with an avcrage of8·5 D) occurs in thc coarsestgrained foresct laminae (CFL). intermediate values (2-120 with an average of 5·3 D) occur in fincrgrained foreset laminac (FFL) and thc lowest values (0·9-1 0 0 with un avcrage of 4·8 D) occur in boltomsctlaycrs (BL). In the cross·bcds the uverage grain sizc rangcs from medium graincd sand in the CFL to fincgrained s,lnd in thc FFL and BL. In all three subf'lcies. the average size of the primary pores isapproximately It/> unit smaller than the averagc grain size. The abundance of unstablc carbonatc clastscorrelatcs with incrcasing avcrage grain size, micritic clasts being most abundant in the CFL. Converscly.quartz content incrcascs with decreasing grain size and is highest in the FFL and BL. Oiageneticdestruction of primary porosity by compact ion and cementation. as well �IS generation of sccondary porositythrough dissolution, were controlled by the original mineralogical composition of the sand. Contrasts ingrain size detcrmine the primary pore size contrasts and differences in composition bctwecn CFL. FFLand BL. Permeability contrasts reflect variations in averagc primary pore size rather than differenccs intotal porosity. Probe permeability contrasts between eFL. FFL and BL depend on contrasts in llveragepore size and contrasts in mineralogical composition between the subfacies.
PB Blackwell Publishing Ltd
SN 0037-0746
YR 1993
FD 1993
LK https://hdl.handle.net/20.500.14352/57078
UL https://hdl.handle.net/20.500.14352/57078
LA eng
NO The definitive version is available at www.blackwell-synergy.com
DS Docta Complutense
RD 8 abr 2025