Pr. Duller et Jd. Floyd, TURBIDITE GEOCHEMISTRY AND PROVENANCE STUDIES IN THE SOUTHERN UPLANDSOF SCOTLAND, Geological Magazine, 132(5), 1995, pp. 557-569
Regional Lithogeochemical data from the Southern Uplands have been use
d to characterize a distinctive stratigraphy across this region. A sui
te of 840 point-counted and petrographically classified greywacke samp
les were used to establish chemical fingerprints for a series of greyw
acke-dominated lithostratigraphical units. These fingerprints were the
n used to evaluate a further 1455 greywacke samples collected througho
ut the Southern Uplands and Longford Down and enabled a series of stri
ke-parallel geochemical tracts to be defined. Four principal geochemic
al groups are recognized, relating to cratonic- and volcanic-derived g
reywacke provenances and both carbonate-rich and hydrothermally altere
d greywackes. Volcanic-derived units display higher Ti, Fe, Mg, Ca, Na
, Mn, Cr, Ga, Ni, Sr, V and Zn values than their cratonic counterparts
, which, with the exception of the carbonate-rich Hawick Group, displa
y higher Si, K, La, Nb, Rb, Th and Zr. Volcaniclastic greywackes displ
ay REE patterns dissimilar to typical post-Archean upper crust, but si
milar to their andesitic components, whereas cratonic groups have REE
patterns close to that of upper crust. Systematic strike-parallel geoc
hemical variation in the Southern Uplands is controlled by petrographi
cal differences which directly reflect provenance, with individual lit
hostratiphical units derived from variable mixtures of ophiolitic, cal
c-alkaline, acid-igneous, low-grade metamorphic and carbonate-rich det
ritus.