Jd. Floyd et Gs. Kimbell, MAGNETIC AND TECTONOSTRATIGRAPHIC CORRELATION AT A TERRANE BOUNDARY -THE TAPPINS GROUP OF THE SOUTHERN UPLANDS, Geological Magazine, 132(5), 1995, pp. 515-521
Prominent aeromagnetic anomalies around Ballantrae in southwest Scotla
nd have long been associated with extensive outcrops of basic/ultrabas
ic igneous rocks in the Midland Valley terrane. However, recent reproc
essing of data from a 1978 detailed aeromagnetic survey has demonstrat
ed excellent correlation between discrete aeromagnetic features and ce
rtain magnetic greywacke formations within the early Caradoc Tappins G
roup. This heterogeneous unit forms the oldest and most northwesterly
tectonostratigraphic tract in the Southern Uplands terrane and is char
acterized by relatively high detrital magnetite (and serpentinite) con
tent and elevated values for Cr and Ni. This suggests original close s
edimentary Links with an ophiolitic terrane not unlike the presently a
djacent Ballantrae Complex (or its extensive along-strike correlatives
), a consideration which has important implications for terrane recons
tructions in this region.