GEOLOGY OF THE GREYMOUTH AREA - GNS Science

CONTENTSABSTRACT . v LATE CRETACEOUS AND TERTIARy . ..25Keywords .INTRODUCTION .THE QMAP SERIES .. v. I...... IT he QMAP geographic information system 1Data sources 1ReliabilityIREGIONALSEITING ...Culture and land-use .GEOMORPHOWGY 3STRATIGRAPHy....CAMBRIAN TO EARLY CARBONIFEROUS.3. 3Southern Alps 3Alpine Fault. . 3Western mountains . . 5Lowland areas 5Plateau areas . 9Present day deformation . 9Offshore bath ymetry. 10Buller lerrane . 11Ordovician sedimentary rocks 11Paragneiss and associated rocks 12Devonian sedimentary rocks 13Takaka terrane . 1.3Cambrian to Ordovician volcanjc and sedimentaryrocks 13Late Devoni an to Early Carboniferous intrusive rocks 14PERMIAN TO EARLY CRETACEOUS .West ofthe Alpine FOliit . . 17Triassic-Jurassic sedjmentary and volcanic rocks 17Early Cretaceous granitoid rocks 17Early Cretaceous sedimentary rocks 17Cretaceous d ikes and high level intrusions. 19East ofthe Alpine Fault: Rakaia terrane .... 21Late Triassic sedimentary rocks . .. 21Late Tri assic semischi stose and schistose rocks 21Structure of Rakaia rocks 22Esk Head belt. . 22Late Jurassic - Early Cretaceous melange 22IIII17Late Cretaceous to Paleocene sedimentary rocks 25Eocene sedimentary rocks 25Oligocene to earliest Miocene sedimentary rocks T!Earl y to Middle Miocene sedimentary rocks 29Late Miocene to Pliocene sedimentary rocks 30Late Pliocene to Earl y Pleistocene sedimentary rocks. 30QUATERNARY.GEOLOGICAL RESOURCES ....ENGINEERING GEOLOGY .......... 31Glacial deposits 31A lluvial deposits 34Alluvial fan deposits ... 34Coastal marine deposits and dunes . .. 34Swamp and lake deposits 34Scree deposits . .. 36Landsli de deposits 36Deposits of human origin . 36TECTONIC HISTORy 37. 39Gold. . 39Ilmenite (and associated minerals) . .. 40Other metallic mjnerals 40Clay... . 41Rock 41Greenstone (nephrite. pounamu) and goodletite 42Limestone. .. ...42Other non-metall ic minerals 42Coal ............ . 43Oil and gas .. .. 45Water 45Warm spri ngs . 45GEOLOGICAL HAZARDS 46Seis l1lotectonic (earthquake) hazard . 46Landslidi ng . 47Tsunam.i................................... . 47. 49Paleozoic-Mesozoic rocks west of the Alpine Fault 49Paleozoic-Mesozoic rocks east of the Alpine Fault 49Tertiary sedimentary rocks 49Quaternary sediments .. 49AVAILABILITY OF QMAP DATA 51ACKNOWLEDGMENTS. . 51REFERENCES . . 52