Table 1. Major and trace element concentrations as well as selected normative compositions for dated rock samples from southern Tanzania	

Sample	MS 2	MS 3	MS 4	MS 5	MS 6	MS 7	MS 8	MS 9	MS 10	MS 12	MS 13	MS 14	MS 15	MS 16	
SiO2	72.46	68.64	71.66	69.19	68.12	67.78	74.25	59.16	35.58	68.19	72.66	71.89	66.27	64.30	
TiO2	0.25	0.56	0.12	0.53	0.55	0.36	0.07	0.77	0.79	0.35	0.25	0.08	0.63	0.99	
Al2O3	13.69	14.76	12.77	13.81	14.52	16.41	13.70	17.01	25.66	15.16	13.84	15.10	15.37	115.04	
Fe2O3	0.93	1.58	0.49	1.70	1.80	0.85	1.03	2.23	4.23	1.39	0.37	1.15	1.15	4.82	
FeO	1.08	1.68	0.33	1.24	1.24	1.14	0.23	4.47	6.68	1.85	0.48	0.24	3.34	1.40	
MnO	0.07	0.04	0.01	0.05	0.05	0.03	0.03	0.12	0.07	0.08	0.01	0.09	0.08	0.11	
MgO	0.56	0.82	0.08	0.67	0.70	1.01	<0.01	3.25	4.26	1.11	0.29	0.03	1.64	1.22	
CaO	2.51	2.38	1.23	2.25	2.36	2.72	0.51	6.18	18.37	3.39	0.99	0.69	4.57	3.67	
Na2O	3.05	3.65	2.99	3.65	3.85	4.40	4.37	3.71	0.13	3.73	2.33	4.63	4.36	3.83	
K2O	3.14	4.41	5.62	3.73	3.91	3.39	4.88	1.67	0.04	3.38	7.17	5.25	1.22	2.87	
P2O5	0.07	0.21	0.02	0.19	0.20	0.12	<0.01	0.20	0.48	0.21	0.03	0.01	0.15	0.27	
LOI	1.09	0.85	0.83	0.78	1.11	0.85	0.47	1.28	1.98	0.80	0.85	0.43	1.09	1,30	
Total	98.89	99.57	96.14	99.16	99.80	99.07	99.50	100.04	98.28	99.64	99.26	99.72	99.87	99.80	
															
Ab	25.81	30.89	25.13	30.89	28.94	37.23	36.98	31.39	0.00	31.56	19.72	39.18	36.89	32.41	
Or	18.56	26.06	32.44	22.04	27.24	20.03	28.66	9.87	9.76	19.98	42.37	31.03	7.21	16.96	
An	12.00	10.44	2.63	9.92	10.46	12.71	2.46	24.83	19.51	14.64	4.72	3.36	18.77	15.37	
Rock type	Granite	Granite/ qtz monz.	Granite	Granite	Qtz mon-
zonite	Grano-
diorite	Granite	Tonalite	Meta-
pelite	Grano-
diorite	Granite	Granite	Tonalite	Grano-
diorite	
															
Ba	1160	1183	656	1007	1418	1954	185	603	<2	1010	926	170	727	435	
Sc	4	6	1	6	8	5	1	17	44	8	<1	3	10	12	
V	22	42	8	38	30	30	2	120	254	49	10	2	69	64	
Cr	10	13	9	9	8	14	1	51	177	13	8	4	13	10	
Co	142	136	144	146	101	125	143	86	55	102	160	118	98	65	
Ni	15	7	2	4	4	7	4	21	53	5	4	2	9	8	
Cu	23	17	5	6	2	3	2	<1	19	5	1	4	<1	7	
Zn	34	44	11	45	59	51	38	90	124	41	38	42	58	82	
Ga	13	19	16	20	21	18	24	20	31	13	15	21	18	27	
Rb	67	111	127	115	99	62	131	45	1	96	120	116	36	39	
Sr	201	358	175	278	275	1109	14	426	797	373	157	43	510	280	
Y	16	23	3	23	38	4	36	19	30	23	2	42	16	85	
Zr	130	335	89	281	527	137	117	127	134	178	124	109	155	498	
Nb	9	15	4	18	18	5	8	6	15	12	3	38	18	59