RELATIONSHIPS BETWEEN HYDROCARBON GENERATION, COAL TYPE AND RANK FOR MIDDLE EOCENE COALS, BULLER COALFIELD, NEW ZEALAND

1997 ◽  
Vol 20 (4) ◽  
pp. 427-458 ◽  
Author(s):  
C. M. Norgate ◽  
C. J. Boreham ◽  
P. J. J. Kamp ◽  
J. Newman
1988 ◽  
Vol 62 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Rodney M. Feldmann ◽  
Robert K. Bearlin

Linuparus (Linuparus) korura n. sp. is described from Bortonian (middle Eocene) rocks in Otaio Gorge, South Canterbury, New Zealand. This discovery represents the first occurrence of the genus in New Zealand and the first notice of a fossil occurrence of the subgenus which is represented by three modern Indo-Pacific species. Comparison of key morphological descriptors suggests that L. korura is related to L. scyllariformis and L. trigonis. A stridulatory mechanism, similar to that seen on modern Linuparus, is described for the first time from the fossil record.


2005 ◽  
Vol 45 (1) ◽  
pp. 601 ◽  
Author(s):  
J.E. Blevin ◽  
K.R. Trigg ◽  
A.D. Partridge ◽  
C.J. Boreham ◽  
S.C. Lang

A study of the Bass Basin using a basin-wide integration of seismic data, well logs, biostratigraphy and seismic/sequence stratigraphy has resulted in the identification of six basin phases and related megasequences/ supersequences. These sequences correlate to three periods of extension and three subsidence phases. The complex nature of facies relationships across the basin is attributed to the mostly terrestrial setting of the basin until the Middle Eocene, multiple phases of extension, strong compartmentalisation of the basin due to underlying basement fabric, and differential subsidence during extension and early subsidence phases. The Bass Basin formed through upper crustal extension associated with three main regional events:rifting in the Southern Margin Rift System;rifting associated with the formation of the Tasman Basin; and,prolonged separation, fragmentation and clearance between the Australian and Antarctic plates along the western margin of Tasmania.The final stage of extension was the result of far-field stresses that were likely to be oblique in orientation. The late Early Eocene to Middle Eocene was a time of rifttransition and early subsidence as the effects of intra-plate stresses progressively waned from east to west. Most of the coaly source rocks now typed to liquid hydrocarbon generation were deposited during this rift-transition phase. Biostratigraphic studies have identified three major lacustrine episodes during the Late Cretaceous to Middle Eocene. The lacustrine shales are likely to be more important as seal facies, while coals deposited fringing the lakes are the principal source rocks in the basin.


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