Page 243 - NEWGEN21-Proceedings-Full

Thursday’s Gossan – Our Early Exploration

1000
diorite Late Porphyry Compositions
QDP
Host rocks at Thursdays Gossan have the trace
monzogabbro
tonalite
dacite element signature of arc magmas: enriched in K
basalt
100 and Pb; depleted in Ti and Nb relative to MORB
andesite
microdiorite
LKD
high P microdiorite Normal fractionation trends
basalt 2
trondhjemite
10
Mt Stavely dacite
High phosphorous microdiorite is enriched in P,

Nd, Sm, Zr, Hf, Eu, Ti and Tb compared to all

other rock types:

1
- indicates magma derived from a heterogenous

source region with a greater component of high

field strength element-enriched, metamorphosed

mantle wedge
0.1
Cs Rb Ba Th U Nb K La Ce Pb Pr Sr P Nd Sm Zr Hf Eu Ti Tb Dy Y Ho Er Tm Yb Lu

MORB normalised spidergram

64