@misc{10481/55414,
year = {2018},
month = {8},
url = {http://hdl.handle.net/10481/55414},
abstract = {Unmanned aerial vehicles (UAVs) are rapidly growing remote sensing platforms
for capturing high-resolution images of exposed rock surfaces. We used a DJI Phantom 3
Professional (P3P) quadcopter to capture aerial images that were used to generate a high-resolution
three-dimensional (3-D) model of the Jokisivu open-pit gold deposit that is located in southwestern
Finland. 158 overlapping oblique and nadir images were taken and processed with Agisoft Photoscan
Pro to generate textured 3-D surface models. In addition, 69 overlapping images were taken from
the steep faces of the open pit. We assessed the precision of the 3-D model by deploying ground
control points (GCPs) and the average errors were found minimal along X (2.0 cm), Y (1.2 cm),
and Z (5.0 cm) axes. The steep faces of the open pit were used for virtual structural measurements
and kinematic analyses in CloudCompare and ArcGIS to distinguish the orientation of different
fracture sets and statistical categorization, respectively. Three distinct fracture sets were observed.
The NW-SE and NE-SW striking fractures form a conjugate geometry, whereas the NNW-SSE striking
fractures cut the conjugate fracture set. The orientation of conjugate fractures match well with the
resource model of the deposit and NW- and NE-trending segments of regional-scale anastomosing
shear zones. Based on the conjugate geometry of fracture sets I and II, and the regional pattern
of anastomosing shear system lead us to interpret an origin of gold mineralization in two stages.
An early N-S or NNW-SSE crustal shortening, corresponding to the regional D4 (ca. 1.83–1.81 Ga) or
pre-D4 (ca. 1.87–1.86 Ga) Svecofennian tectonic event(s) that produced anastomosing shear zones.
Subsequent E-W directed D5 contraction (ca. 1.79–1.77 Ga) partly reactivated the anastomosing shear
zones with the formation of conjugate system, which controlled the migration of fluids and gold
mineralization in SW Finland.},
publisher = {MDPI},
keywords = {UAV},
keywords = {Open-pit mine},
keywords = {Gold deposit},
keywords = {Structure-from-motion},
keywords = {Shear fractures},
title = {Virtual Structural Analysis of Jokisivu Open Pit Using ‘Structure-from-Motion’ Unmanned Aerial Vehicles (UAV) Photogrammetry: Implications for Structurally-Controlled Gold Deposits in Southwest Finland},
author = {Sayab, Mohammad and Aerden, Domingo Gerard and Paananen, Markku and Saarela, Petri},
}