GAL Aquifer Formation Extents v01

Abstract

The dataset was derived by the Bioregional Assessment Programme from multiple source datasets. The source datasets are identified in the Lineage field in this metadata statement. The processes undertaken to produce this derived dataset are described in the History field in this metadata statement.

This dataset is a model of the extent of aquifers in the Galilee geologic basin that is Moolyember Formation, Clematis Formation, Rewan Formation, Bandanna/Betts Creek Formation, Joe Joe Group, Basement (bottom of Galilee Basin).

Purpose

This dataset was created to provide formation extents for aquifers in the Galilee geological basin

Dataset History

A Quality Assurance (QA) and validation process was conducted on the original well and bore data to choose wells/bores that are within 25 kilometres of the BA Galilee Region extent.

The QA/Validation process is as follows:

1. Well data

   a. Obtained excel file "QPED_July_2013_galilee.xlsx" from GA

   b. Based on stratigraphic information in "BH_costrat" tab formation names were regularised and simplified based on current naming conventions.

   c. Simplified names added to QPED_July_2013_galileet.xlsx as "Steve_geo" and "Steve_group"

   d. Produced new file "GSQ_Geology.xlsx" contained decimal latitude and longitude, KB elevation, top of unit in metres from KB, top of unit in metres AHD, bottom of unit in metres from KB, bottom of unit in metres AHD, original geology, simplified geology, simplified Group geology.

          i.   KB obtained from "BH_wellhist"
   
          ii.  Where no KB information was available ie KB=0, sample the 1S DEM at the well's location to obtain height. KB=DEM+10. Marked well as having lower reliability.
   
          iii. Calculated Top_m_AHD = KB - Top_m_KB
   
          iv.  Calculated Bottom_m_AHD = KB - Bottom_m_KB
   

   e. Brought GSQ_Geology.xlsx into ArcGIS

   f. Selected wells based on "Steve_geo" field for each model layer to produce a geodatabase for layer

          i.   GSQ_basement_wells
   
          ii.  GSQ_top_joe_joe_group
   
          iii. GSQ_top_bandanna_merge
   
          iv.  GSQ_rewan_group
   
          v.   GSQ_clematis
   
          vi.  GSQ_moolyember
   

   g. Additional wells and reinterpreted tops added to appropriate geodatabase based on well completion reports

   h. Additional wells added to coverages to help model building process

          i.   Well_name listed as Fake
   
          ii.  Exception being GSQ_top_basement_fake which was created as a separate geodatabase
   

   i. Created additional geodatabase for each model layer to highlight wells where the relevant model layer does not exist.to guide extent definition

          i.   GSQ_joejoe_null
   
          ii.  GSQ_rewan_ggroup_null
   
          iii. GSQ_clematis_null
   
          iv.  GSQ_moolyember_null
   

2. Bore data

   a. Obtained QLD_DNRM_GroundwaterDatabaseExtract_20131111 from GA

   b. Used files REGISTRATIONS.txt, ELEVATIONS.txt and AQUIFER.txt to build GW_stratigraphy.xlsx

          i.   Based on RN
   
          ii.  Latitude from GIS_LAT (REGISTRATIONS.txt)
   
          iii. Longitude from GIS_LNG (REGISTRATIONS.txt)
   
          iv.  Elevation from (ELEVATIONS.txt)
   
          v.   FORM_DESC from (AQUIFER.txt)
   
          vi.  Top from (AQUIFER.txt)
   
          vii. Bottom from (AQUIFER.txt)
   

   c. Brought GW_stratigraphy.xlsx into ArcGIS

   d. Created gw_bores_galilee_dem

          i.   Sampled 1S DEM to obtain ground level elevation column RASTERVALU
   
          ii.  Created column top_m_AHD by RASTERVALU - Top
   

   e. Selected bores based on "FORM_DESC" field for each model layer to produce a geodatabase for each layer.

          i.   Gw_basement
   
          ii.  GW_bores_joe_joe_group
   
          iii. GW_bores_bandanna
   
          iv.  Gw_bores_rewan
   
          v.   Gw_bores_clematis
   
          vi.  Gw_bores_moolyember
   

3. Surface geology

   a. Extracted surface geology from QUEENSLAND GEOLOGY_AUGUST_2012 using Galilee BA region boundary with 25 kilometre boundary to form geodatabase QLD_geology_galilee

   b. Selected relevant surface geology from QLD_geology_galilee based on field "Name" for each model layer and created new geodatabase layers

          i.   Basement_geology: Argentine Metamorphics,Running River Metamorphics,Charters Towers Metamorphics; Bimurra Volcanics, Foyle Volcanics, Mount Wyatt Formation, Saint Anns Formation, Silver Hills Volcanics, Stones Creek Volcanics; Bulliwallah Formation, Ducabrook Formation, Mount Rankin Formation, Natal Formation, Star of Hope Formation; Cape River Metamorphics; Einasleigh Metamorphics; Gem Park Granite; Macrossan Province Cambrian-Ordovician intrusives; Macrossan Province Ordovician-Silurian intrusives; Macrossan Province Ordovician intrusives; Mount Formartine, unnamed plutonic units; Pama Province Silurian-Devonian intrusives; Seventy Mile Range Group; and Kirk River beds, Les Jumelles beds.
   
          ii.  Joe_joe_geology: Joe Joe Group
   
          iii. Galilee_permian_geology: Back Creek Group, Betts Creek Group, Blackwater Group
   
          iv.  Rewan_geology: Rewan Group
   
                1. Later also made dunda_beds_geology to be included in Rewan model: Dunda beds
   
          v.   Clematis_geology: Clematis Group
   
                1. Later also made warang_sandstone_geology to be included in Clematis model: Warang Sandstone
   
          vi.  Moolyember_surface_geology: Moolyember Formation
   

The formation extents were derived as follows:

1. Where surface geology outcropped primarily on eastern margin of the basin. The aquifer extent was confined to the eastern margin of the outcrop geology.

2. Using the well and bore datasets, the extent was edited to include all wells/bores where the relevant layer was present and to exclude wells/bores where the relevant layer was absent.

3. Where no other information was present, the aquifer extent was guided by the shape of the Galilee Basin as shown in OZ SEEBASE.

4. The extents were saved as polygons and converted to grids using the Polygon to Raster tool.

Dataset Citation

Bioregional Assessment Programme (2014) GAL Aquifer Formation Extents v01. Bioregional Assessment Derived Dataset. Viewed 12 December 2018, http://data.bioregionalassessments.gov.au/dataset/e77f61d8-86d1-442a-a6ba-4256ae470595.

Dataset Ancestors

• Derived From Queensland Geological Digital Data - Detailed state extent, regional. November 2012

• Derived From QLD Department of Natural Resources and Mines Groundwater Database Extract 20142808

• Derived From Phanerozoic OZ SEEBASE v2 GIS

• Derived From Queensland petroleum exploration data - QPED