title: Stratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic change

authors: Green, John D.

subjects: paleolimnology

abstract: The stratigraphy and geomorphology of Lake Maratoto and its surrounds were investigated as part of a programme of paleolimnological studies based on sediment cores from lakes in northern North Island. Changes in the lake and catchment were inferred from variations in sediment character, the correlation and timing being determined from distinctive tephra layers in the sediments and by radiocarbon dating. Nineteen new C-l4 dates, on gyttja or peat, are reported (old T½, years B.P,): 11 on tephras (Mamaku Ash 6830 ±90. Wk227; Rotoma Ash 8370 ± 90, Wk522; 8350 ± 100, Wk523; Opepe Tephra 9370 ± 210, Wk230; Mangamate Tephra 9700 ± 140, Wk23l; 10000 ± 120, Wk232; Waiohau Ash 12 200 ± 230, Wk233; 12500 ± 190, Wk234; 12450 ± 200, Wk5l5; 12300 ± 190,Wk516; RotoruaAsh 13450 ± 120, Wk511); 5 on the deposition of Hinuera Formation alluvium (16 300 ± 250, Wk239; 16 900 ± 470, Wk240; 17050 ± 200, Wk358; 16200 +360 -340, Wk509; 15 850 ± 130, Wk510); and 3 on basal peat of the Rukuhia bog (10 250 ± 90, Wk114; 15200 ± 130, Wk534; 10600 ± 90, Wk553).
Lake Maratoto originated c. 17 000 years ago when a small valley was dammed by volcanogenic alluvium (Hinuera Formation). From c. 17 000 to c. 14 000 years ago the lake was about 2 m deep with clear water. Marginal peat first developed at c. 15000 years ago, reducing the area of the lake by about one-half by c. 13 000 years ago. Lake area then expanded, possibly because of marginal erosion and/or oxidation of the peat, to its maximum size at the present day. The adjacent Rukuhia peat bog grew rapidly from c. 11 000 years ago and is now 8 m thick immediately to the west of the lake. As a result of this growth, the lake became dystrophic and deepened (3.5 m at c. 7000 years ago, 6.4 m at c. 2000 years ago, and 7. 1 m today).
The developmental history suggests that net precipitation increased at c. 15 000 years ago, increased further at c. 11 000 years ago, remaining high to c. 7000 years ago at least, but with a decline at or before c. 2000 years ago. There may have been a distinctly wetter or windier period from c. 10 000 to 9000 years ago.
This interpretation is consistent with other reconstructions of postglacial climate in the Southern Hemisphere.

text: Stratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic change The stratigraphy and geomorphology of Lake Maratoto and its surrounds were investigated as part of a programme of paleolimnological studies based on sediment cores from lakes in northern North Island. Changes in the lake and catchment were inferred from variations in sediment character, the correlation and timing being determined from distinctive tephra layers in the sediments and by radiocarbon dating. Nineteen new C-l4 dates, on gyttja or peat, are reported (old T½, years B.P,): 11 on tephras (Mamaku Ash 6830 ±90. Wk227; Rotoma Ash 8370 ± 90, Wk522; 8350 ± 100, Wk523; Opepe Tephra 9370 ± 210, Wk230; Mangamate Tephra 9700 ± 140, Wk23l; 10000 ± 120, Wk232; Waiohau Ash 12 200 ± 230, Wk233; 12500 ± 190, Wk234; 12450 ± 200, Wk5l5; 12300 ± 190,Wk516; RotoruaAsh 13450 ± 120, Wk511); 5 on the deposition of Hinuera Formation alluvium (16 300 ± 250, Wk239; 16 900 ± 470, Wk240; 17050 ± 200, Wk358; 16200 +360 -340, Wk509; 15 850 ± 130, Wk510); and 3 on basal peat of the Rukuhia bog (10 250 ± 90, Wk114; 15200 ± 130, Wk534; 10600 ± 90, Wk553).
Lake Maratoto originated c. 17 000 years ago when a small valley was dammed by volcanogenic alluvium (Hinuera Formation). From c. 17 000 to c. 14 000 years ago the lake was about 2 m deep with clear water. Marginal peat first developed at c. 15000 years ago, reducing the area of the lake by about one-half by c. 13 000 years ago. Lake area then expanded, possibly because of marginal erosion and/or oxidation of the peat, to its maximum size at the present day. The adjacent Rukuhia peat bog grew rapidly from c. 11 000 years ago and is now 8 m thick immediately to the west of the lake. As a result of this growth, the lake became dystrophic and deepened (3.5 m at c. 7000 years ago, 6.4 m at c. 2000 years ago, and 7. 1 m today).
The developmental history suggests that net precipitation increased at c. 15 000 years ago, increased further at c. 11 000 years ago, remaining high to c. 7000 years ago at least, but with a decline at or before c. 2000 years ago. There may have been a distinctly wetter or windier period from c. 10 000 to 9000 years ago.
This interpretation is consistent with other reconstructions of postglacial climate in the Southern Hemisphere.

year: 1985

title: Further validation of the New Zealand test of adult reading (NZART) as a measure of premorbid IQ in a New Zealand sample

authors: Lichtwark, Irene Tatjana

subjects: IQ estimation

abstract: Premorbid IQ estimates are used to determine decline in cognitive functioning following trauma or illness. This study aimed to: 1) further validate the New Zealand Adult Reading Test (NZART) in a New Zealand population and compare its performance to the UK developed National Adult Reading Test, and 2) develop regression formulae for the NZART to estimate Wechsler Adult Intelligence Scale-IV (WAIS–IV) IQ scores. The 67 participants (53 females; 16 Māori), aged 16 to 90 years old (mean age = 46.07, SD 23.21) completed the WASI-IV, the NART and the NZART. The NZART predicted Verbal Comprehension Index (VCI) scores slightly better than the NART (r =.63 vs. r = .62) and explained 33% of the variance in FSIQ scores. Reasons for developing regression formulae for the NZART are discussed, regression formulas for the NZART based on the WAIS–IV are included and suggestions of alternate ways of determining premorbid IQ are made.

text: Further validation of the New Zealand test of adult reading (NZART) as a measure of premorbid IQ in a New Zealand sample Premorbid IQ estimates are used to determine decline in cognitive functioning following trauma or illness. This study aimed to: 1) further validate the New Zealand Adult Reading Test (NZART) in a New Zealand population and compare its performance to the UK developed National Adult Reading Test, and 2) develop regression formulae for the NZART to estimate Wechsler Adult Intelligence Scale-IV (WAIS–IV) IQ scores. The 67 participants (53 females; 16 Māori), aged 16 to 90 years old (mean age = 46.07, SD 23.21) completed the WASI-IV, the NART and the NZART. The NZART predicted Verbal Comprehension Index (VCI) scores slightly better than the NART (r =.63 vs. r = .62) and explained 33% of the variance in FSIQ scores. Reasons for developing regression formulae for the NZART are discussed, regression formulas for the NZART based on the WAIS–IV are included and suggestions of alternate ways of determining premorbid IQ are made.

year: 2013

title: Piahana Hou: a Ngati Rahiri rangatira

authors: Hart, Philip

abstract: Piahana Hou, as the half-brother of Karauna Hou, had an illustrious ancestry, but to Pakeha he was known as, briefly, the skipper of a river steamer and, for most of his life, as a labourer. His interests in several blocks of land enabled him to obtain money through selling some of his holdings, but he never became prosperous. He had minimal involvement in mining at Te Aroha.
Piahana came to prominence not as a rangatira but as a drunk, who was even involved in a bar fight at Te Aroha. Despite this weakness, his high status meant that hundreds attended his splendid tangi. Unlike some other rangatira, he did not use his status to play an important role in either Maori or Pakeha society.

text: Piahana Hou: a Ngati Rahiri rangatira Piahana Hou, as the half-brother of Karauna Hou, had an illustrious ancestry, but to Pakeha he was known as, briefly, the skipper of a river steamer and, for most of his life, as a labourer. His interests in several blocks of land enabled him to obtain money through selling some of his holdings, but he never became prosperous. He had minimal involvement in mining at Te Aroha.
Piahana came to prominence not as a rangatira but as a drunk, who was even involved in a bar fight at Te Aroha. Despite this weakness, his high status meant that hundreds attended his splendid tangi. Unlike some other rangatira, he did not use his status to play an important role in either Maori or Pakeha society.

year: 2016