This layer shows a compilation of separate sediment layers (Mud, Sand, and Gravel) to portray a combined picture of bottom composition. Rock along with nine sediment types were initially defined according to the Folk sediment classification system based on the percentage of mud, sand, and gravel within cells (Folk et al., 1970). These were then grouped into mud, mixed sediment (mud + gravel and mud + gravel + sand), sand, and course sediment (gravel and gravel + sand) based on the figure below and are shown with rocky reef areas overlayed. Most of New Zealand’s seafloor is covered by soft sediments, which tend to be characterized by less macrobiotic biodiversity than course sediment and rocky areas, although different key biogenic habitats can be found in each of these habitat types. Different configurations of grain sizes and materials are indicative of geologic history, hydrodynamic conditions, seafloor topography and biological activity and as a result host differing communities of organisms.

Source and reference:

“The Folk sediment triangle and the hierarchy of Folk classification (15, 6 and 4 classes, plus an additional class “rock and boulders,” indicated by the arrow) used in the EMODnet Geology project.” (Kaskela et al., 2019).

Folk RL, Andrews PB, Lewis DW. 1970. Detrital sedimentary rock classification and nomenclature for use in New Zealand. New Zealand Journal of Geology and Geophysics. 13:937–968. DOI:10.1080/00288306.1970.10418211. https://www.tandfonline.com/doi/abs/10.1080/00288306.1970.10418211

Kaskela, A. M., Kotilainen, A. T., Alanen, U., Cooper, R., Green, S., Guinan, J., et al. (2019). Picking up the pieces–Harmonising and collating seabed substrate data for European maritime areas. Geosciences 9:84. doi: 10.3390/geosciences9020084 https://www.researchgate.net/publication/331094612_Picking_Up_the_Pieces-Harmonising_and_Collating_Seabed_Substrate_Data_for_European_Maritime_Areas

References for sediment and rock layers included:

Bostock, H., C. Jenkins, K. Mackay, L. Carter, S. Nodder, A. Orpin, A. Pallentin, and R. Wysoczanski. 2019. Distribution of surficial sediments in the ocean around New Zealand/Aotearoa. Part A: continental slope and deep ocean. New Zealand Journal of Geology and Geophysics 62:1-23.

Bostock, H., C. Jenkins, K. Mackay, L. Carter, S. Nodder, A. Orpin, A. Pallentin, and R. Wysoczanski. 2019. Distribution of surficial sediments in the ocean around New Zealand/Aotearoa. Part B: continental shelf. New Zealand Journal of Geology and Geophysics 62:24-45. https://www.tandfonline.com/doi/full/10.1080/00288306.2018.1523199

Jenkins CJ. 1997. Building offshore soils databases. Sea Technology. 38(12):25–28.

Smith, A. N., Duffy, C., Anthony, J., and Leathwick, J. R. 2013. Predicting the distribution and relative abundance of fishes on shallow subtidal reefs around New Zealand, Department of Conservation, Wellington, New Zealand

This layer shows a compilation of separate sediment layers (Mud, Sand, and Gravel) to portray a combined picture of bottom composition. Rock along with nine sediment types were initially defined according to the Folk sediment classification system based on the percentage of mud, sand, and gravel within cells (Folk et al., 1970). These were then grouped into mud, mixed sediment (mud + gravel and mud + gravel + sand), sand, and course sediment (gravel and gravel + sand) based on the figure below and are shown with rocky reef areas overlayed. Most of New Zealand’s seafloor is covered by soft sediments, which tend to be characterized by less macrobiotic biodiversity than course sediment and rocky areas, although different key biogenic habitats can be found in each of these habitat types. Different configurations of grain sizes and materials are indicative of geologic history, hydrodynamic conditions, seafloor topography and biological activity and as a result host differing communities of organisms.

Source and reference:

“The Folk sediment triangle and the hierarchy of Folk classification (15, 6 and 4 classes, plus an additional class “rock and boulders,” indicated by the arrow) used in the EMODnet Geology project.” (Kaskela et al., 2019).

Folk RL, Andrews PB, Lewis DW. 1970. Detrital sedimentary rock classification and nomenclature for use in New Zealand. New Zealand Journal of Geology and Geophysics. 13:937–968. DOI:10.1080/00288306.1970.10418211. https://www.tandfonline.com/doi/abs/10.1080/00288306.1970.10418211

Kaskela, A. M., Kotilainen, A. T., Alanen, U., Cooper, R., Green, S., Guinan, J., et al. (2019). Picking up the pieces–Harmonising and collating seabed substrate data for European maritime areas. Geosciences 9:84. doi: 10.3390/geosciences9020084 https://www.researchgate.net/publication/331094612_Picking_Up_the_Pieces-Harmonising_and_Collating_Seabed_Substrate_Data_for_European_Maritime_Areas

References for sediment and rock layers included:

Bostock, H., C. Jenkins, K. Mackay, L. Carter, S. Nodder, A. Orpin, A. Pallentin, and R. Wysoczanski. 2019. Distribution of surficial sediments in the ocean around New Zealand/Aotearoa. Part A: continental slope and deep ocean. New Zealand Journal of Geology and Geophysics 62:1-23.

Bostock, H., C. Jenkins, K. Mackay, L. Carter, S. Nodder, A. Orpin, A. Pallentin, and R. Wysoczanski. 2019. Distribution of surficial sediments in the ocean around New Zealand/Aotearoa. Part B: continental shelf. New Zealand Journal of Geology and Geophysics 62:24-45. https://www.tandfonline.com/doi/full/10.1080/00288306.2018.1523199

Jenkins CJ. 1997. Building offshore soils databases. Sea Technology. 38(12):25–28.

Smith, A. N., Duffy, C., Anthony, J., and Leathwick, J. R. 2013. Predicting the distribution and relative abundance of fishes on shallow subtidal reefs around New Zealand, Department of Conservation, Wellington, New Zealand