Such distinct hematitic
, red cores and yellow, goethitic cortexes are common features of Fe nodules (Amouric et al.
The "Duke's Red" is a beautiful hematitic
limestone found in a limited deposit at Youlgreave in Derbyshire in the 1820s.
At Site 151 the cross-laminated boundary layer is rich in planktonic foraminifers, which alternate with hematitic
smectite laminae derived from the alteration of tektites (Izett et al.
They are generally coated with rusty sulphidic, hematitic
and manganese staining.
Interparticle cements can exceed 30 percent by volume of oolitic grainstone and include very early isopachous marine spar, hematitic
coats of uncertain origin, vadose meniscus microcrystalline spar, and pore-filling meteoric spar (Haywick and Kopaska-Merkel, in prep).
In south-western Mali close to the Senegal border, the Bafing-Makana hematitic
iron ore deposit is estimated to contain 150 Mt at 36-37% Fe.
However, medium grained, moderately sorted grey sandstone sequence with hematitic
altered beds, trough cross beds, wood logs and presence ofterrestrial vertebrate fossils all are indicative ofa fluvial system.
The sulphide mineralisation was primarily pyrite with minor chalcopyrite (copper sulphide) accompanied by strong chlorite and in places siliceous and hematitic
(jasperoidal) alteration.A competent medium to coarse grained grey granite/granodiorite with minor disseminated pyrite was intersected from 675 metres to the end of the hole at 812 metres final depth.Low order copper anomalism was recorded in assay results for the interval between 632 metres and 649.5 metres (average 280ppm Cu, peak assay value 0.2% Cu).Neumayer #1 Target (drill hole NEUDD-01)NEUDD-01 was drilled 25km to the north-north-east of AUGDD-01 to test a high order residual gravity anomaly and coincident magnetic anomaly located on a regional scale north-west trending fault structure.
(1987) from XRD patterns of iron oxide concentrated clays, was 0.85 for the Rhodic Acrudox and 0 for the Xanthic Acrustox, indicating that the former can be classified as hematitic
(Hm/Hm+Gt >0.6) and the latter as goethitic (Hm/Hm+Gt <0.2) (EMBRAPA 1999).