Geohistory tourism of the Brisbane CBD

Sea floor sediments

 Brisbane CBD Geohistory

– 300 million years in the making

The concept of geohistory tourism  for Brisbane’s CBD is linked to its geological history, ecology and human interactions.

This includes:

  1. Geological processes, landscapes and ecology and how these change with time
  2. Plants and animals in geological and human time frames
  3. The traditional local indigenous inhabitants, their life style prior to European settlement
  4. Plants and animals in geological and human time frames
  5. The traditional local indigenous inhabitants, their life style prior to European settlement
  6. The initial setting up of Brisbane city and its effects on local environment and inhabitants
  7. Conflicts between indigenous inhabitants and European settlement
  8. Water resources and sources of building stone in the city
  9. The changing scape of the city
  10. Current and future directions, facilities and walking trails

Sea floor sediments

ROCKS IN THE CBD

  • Two Rock Units – The Neranleigh-Fernvale beds (NFB) and the Brisbane Tuff
  • The age of NFB was unknown until 1974 – they were thought to be Pre-Cambrian as no fossils had been discovered.
  • The first fossils found in the South D’Aguilar Sub Province along the Mount Nebo-Mount Glorious road were poorly preserved brachiopods, bryozoa and crinoid. Follow up zircon dating showed an age of 351 Ma from the enclosing sediments. Later radiolarian fossils from cherts at Lake Manchester are Devonian or younger

Rock bodies

The Neranleigh – Fernvale beds were deposited in the deep ocean in the Late Devonian to Early Carboniferous (about 360-320million years ago), were accreted to the continent and underwent deformation from the Late Carboniferous to Early Permian (to about 300 million years before present).  Examples of deformation of these old rocks can be seen in outcrops adjacent to the eastern abutment of the Captain Cook Bridge.

Following that the Brisbane Tuff – a cataclysmic stratovolcanic eruption similar in style to Mount St Helens  (and represented locally by the Kangaroo Point Cliffs) was deposited in deep stream valleys in the Late Triassic (230Ma). An animation of the deposition of the tuff can be seen by downloading the Konect Tourism app from the app store .  Over time these rock bodies were eroded and the landscape become more subdued.  The rock bodies that formed the valleys to the Brisbane Tuff were more susceptible to erosion that the tuff, consequently the current landscape is an inverted landscape with rocks that originally formed the valley are now forming a hill in the landscape.

 

Mount St Helens Style eruption

The vegetation preserved in fossils in the tuff indicate a wet climate with dinosaurs, seed ferns, and cycads were abundant at the time of the Brisbane Tuff eruption.

The vegetation at the time of the originial aboriginal settlement indicates thick rain forest on the southern bank of the Brisbane River and drier eucalypt forest on the northern bank.

Original local inhabitants and conflicts of colonial settlement

The Turrbal people, according to Tom Petrie (a founding family of modern-day Brisbane,‘Meeaan-jin’), occupied the area of land extending far inland to the Gold Creek or Moggill, as far north as North Pine, and south to the Logan River.

They were fishing people and the Brisbane River and Creeks and swamps around Brisbane were vital food sources. the land, the river and its tributaries were the source and support of life in all its dimensions. . The river’s abundant supply of food included fish, shellfish, crab, and shrimp. Good fishing places became campsites and the focus of group activities with groups of up to 300.

  • The free settlers didn’t recognise local aboriginal ownership and did not compensate the Turrbul and some serious affrays and conflicts ensued.
  • By 1869, many Turrbul had died from gunshot or disease, but the Moreton Bay Courier frequently mentioned local indigenous people working and living in the district.  There was constriction of their movement and the term boundary road reflected the region that local aboriginal were not allowed closer to the CBD.
  • In the1840s to 1860s, the settlement relied increasingly on goods obtained through trade with aboriginals—firewood, fish, crab, shellfish—and services they provided such as water-carrying, tree-cutting, fencing, ring-barking, stock work and ferrying.
  • Since the arrival of Europeans the rate of change in the natural environment has increased dramatically. The district was characterized by open woodlands and rain forest once fringed the Brisbane River and its major tributaries, especially on the broader floodplains such as St. Lucia and Seventeen Mile Rock when land was required in Brisbane for housing and farming trees were felled, creeks (Creek Street), estuaries, gullies and wetlands (e.g Brisbane City Hall) were  filled-in  and local plants and animals were reduced with the introduction of foreign species
  • Exotic plants in many of the creeks of the Brisbane River have substantially changed the aquatic environment.  These include grasses, e.g. para grass (Brachiaria mutica), and green couch (Cynodon dactylon) which reduce free water in stream channels, and flow velocities in the lower reaches of most creeks and Creeks extinguishing native aquatic vegetation.  Floating exotic plants including water hyacinth (Eichornia crassipes), salvinia (Salvinia auriculate) and water lettuce (Pistia stratiotes) blanket some reaches. Native aquatic macrophytes have declined, apparently due to dredging, saltation and other disturbances (Arthington et al, 1983).” (Task M2 State of the Brisbane River and Moreton Bay and Waterways – Gutteridge, Haskins & Davey Pty Ltd, p. 6-9 1996). Arthington et al, 1983).
  • Major weeds in the catchment include:
  • Lantana monteuidensis (creeping lantana), Lantana camera (lantana), Baccharis halimfolia (groundsel bush), Celtis sinensis (Chinese elm), Cinnamomum camphora (camphor laurel), Protasparagus africanis (a climbing asparagus), Bryophyllum spp. (mother of millions), Cassia spp. (exotic cassia)
  • Up to 60% of urban bushland remnants suffer from some level of weed invasion, either from human influence (dumping of garden clippings, misguided revegetation) or by natural means (wind blown seeds, dispersal by birds and animals, spread by water) (BCC, 1990).

Brisbane From country town to thriving capital city – short history

  • Earliest water supply from the spring at Spring Hill was stored at the tank at Tank Street, this water supply became polluted fron animal excrement, which caused significant typhoid health problems  in Brisbane
  • 1859 – City of Brisbane established and separation from NSW  and John Petrie became  first mayor
  • First reticulated water supply 1871 and 1882 from Enoggera Creek and stored in tanks on Wickham Terrace and fed by gravity feed into the city. This reticulated water supply fed a local population of more than 50 000 inhabitants from the 1880s.
  • First railway in Brisbane went from Roma Street to Ipswich in 1879.
  • A demonstration of electric lighting of lamp posts along Queen Street in 1882 was the first recorded use of electricity for public purposes in the world.
  • First horse-drawn, then electric trams operated in Brisbane from 1885 until 1969.
  • The first reservoir was built in 1871, and the second in 1882. Both were built primarily of red-brick and mortar, set in-ground. Interiors feature columns and arches between walls for reinforcement. At the time of planning, Spring Hill was considered to be the ideal location for a Brisbane water source, due to its elevation above most of what is now Brisbane City. Water was sourced from Enoggera Dam via gravity feed.
  • Significant historical buildings include the Commissariat Store along Queens Wharf Road, the old Windmill (along Wickham Terrace)  and the Treasury Building (Casino) at the Raddison Plaza
  • The proclamation of the Commonwealth of Australia was read on the first of January, 1901 from the Treasury Building facing William Street.
  • Brisbane was regarded as a country town rather than a major city and McAthur Chambers in Queen Street was the headquarters in World War 2 for Douglas MacArthur the commander of allied forces in the Pacific
  • the long period of control of the Country party by Johannes Bjelke Petersen  (1969-1988) had both positive and negative effects on the city. During his time in office there was a diminution of public right to demonstrate, however despite much controversy there was important infrastructure was constructed eg Wivehoe Dam, but significant public buildings were destroyed by Dean brothers in the name of progress e.g., the Bellevue Hotel and Cloudland.
  • In 1988 the World Expo at the current Southbank site fundamentally changed the concept of dining out in Brisbane
  • In the past 20 years, large complexes of units have been constructed in the CBD and significant student migration of Asian students has been a feature of urban Brisbane
  • Road tunnels have been constructed to reduce traffic congestion and reduce travel times across the CBD.
  • Queens Wharf is the oldest roadway in the city and was constructed to bring material from the first wharf on the northern bank of river at the beginning of colonial settlement.  This roadway  fronts the Commissariat Store.  This area is being renewed as part of a major redevelopment of the inner city.

For any additional information on Geotourism, your projects and details of experience contact me.

Project Management Styles

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Styles of Project Management

Cranfield Geosevices identifies the style of project and program management appropriate for client demand and documentation.  There are a range of project management tools including Gant charts, risk management strategies, planning software and budgeting . For short term projects project management is usually an internal process managed by Cranfield Geoservices based on agreed terms of reference for the project with the client.  Agreement with a client identifies staged project outcomes based on delivery of different aspects of the project as either simply outlined in an Excel spreadsheet with identified possible road blocks or delays to  the work flow based on lack of critical data or other issues.

In larger projects there is commonly a more formal project management structure based on more detailed project management  documentation of agreed outcomes and payment using project management software as required by the client.  If these schedules require input of information and resources by the client these are clearly identified at the commencement of the project to avoid any misconception by both parties.

For any additional information on styles of management for your projects and details of my experience contact me.

 

Geological Mapping Projects

Norhtern Surat radiometrics

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Data sets used for  mapping projects

Cranfield Geoservices (CGSI) uses all available data and knowledge to create or update geological maps. The goal is to integrate an updated understanding of the regional structure and geological evolution into local prospects.  A comprehensive understanding of how airborne geophysical and remotely sensed imagery enhance interpretation of the local geology is vital in designing your exploration program.

Regional Airborne geophysical surveys

Airborne Geophysical Surveys for geological mapping use both radiometric and magnetic imagery. Radiometric surveys measure gamma rays which are continuously being emitted from the Earth by natural decomposition of some common radiogenic minerals. The use of radiometric imagery to distinguish differences in rock chemistry between and within geological units has been applied most extensively for granitic rocks, but it is gaining in acceptance to use to distinguish chemical differences in sedimentary sequences related to provenance and elements of a mineralised system including:

  • Exploration for a range of uranium deposits.
  • Special applications such as exploration for diamonds by assisting in location of kimberlite.
  • Porphyry copper  deposits particularly in zones of potassic alteration
  • Exploration for gold using the Au-U association in specific localities.
  • Exploration for radioactive halos over hydrocarbon deposits.

Geophysical surveys for subsurface interpretation

Subsurface geophysical techniques for creating a solid geology map and underlying resources  (ie on of an interpreted geology below the surface also include:-

Magnetic Surveys

  • Magnetic surveys – which measure variations in the Earth’s magnetic field due to the presence of magnetic minerals. Subtle changes to these minerals are used to interpret rock types and assist in identifying resources. These surveys can be aerial, on the surface or in down-hole logging tools. Magnetic surveys are commonly used in  mineral exploration.

Gravity geophysical surveys

  •  Gravity surveys – include both ground and airborne surveys.  The instrumentation identifies variations in rock density in the Earth’s crust. These surveys are commonly used in conjunction with magnetic surveys to locate regions of higher density that may correlated with economic mineralization.

Induced Polarisation geophysical surveys

  •  Induced Polarisation (IP)  surveys  induce an electric field in the ground and measure the chargeability and resistivity of the subsurface to locate changes in the electric currents due to variations caused by rocks and minerals.

Electromagnetic geophysical surveys

  • Electromagnetic (EM) surveys create an induced electromagnetic field and measure the three dimensional variations in conductivity (capacity to conduct electricity) within the near-surface soil and rock. Uses include  the location metallic minerals,and to understand groundwater and salinity. In the case  of groundwater salinity there is a capacity to model the salinity at different depths.

 

For any additional information on your projects and details of experience contact me.

Basin Analyses Integration

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Basin analyses – data integration

High level basin analyses must consider the information gained from all public open file data available online and the use of the most recent company data as required to interpret and solve local anomalies .  The following discussion identifies the publicly available data to undertake an analysis of Queensland’s basins.  Each data set tells us something about the underlying rocks, but a results from interpretation of a single data set is not always directly applicable  to the results of interpretation of another.  A linking flow chart of the information from each data set to a final interpretation may allow a more comprehensive understanding for each basin. The sequence of using data sets is always from a regional concept (1:250 000 to 1:100 000 scale)  to the detailed exploration project (<1:10,000 scale), and it is important to understand the geology at all scales using the appropriate technique for each scaling parameter.

Queensland Resources

The location of major mineral and energy resources of the state is given on a state-wide basis by the Department of Natural Resources and Mines (qld-resources-map (1))

The Late Palaeozoic to Mesozoic basins of Queensland have been extensively drilled particularly for energy resources (coal, oil and gas), but much of the mapping dates back to the 1960s and 1970s.  Linking the outcropping geology to a subsurface information delivers a holistic three dimensional view of these basins.

Much of Queensland has been flown by airborne geophysics and this data set has not been used extensively to update the detailed geology of these basins.  To maximise the potential of these basins it is important that all this data is used to update the interpretation of these economic basins.

This requires integration of available data sets and the solving of anomalies in interpretation locally and regionally.  The variation in the type of data and the scale of the information poses a range of issues in data integration.  Concepts of geology have been modified from the early mapping of the basin areas with updates to knowledge from sequence stratigraphy, chronstratigraphy and lithostratigraphy.

To generate a comprehensive interpretation of these basins requires an integrated approach by government and industry data to deliver a three dimensional basin concept to maximise knowledge of energy resources within basins and potential mineral resources at the margins of these basins.

Large Publicly available data sets that can be integrated with your project

A major  coverage publicly available source of data is the geophysical data coverage of Queensland.  A major significant coverage of  data is Geophysical Data coverage.  

Major subsets of this data are the 2D and 3D seismic lines mainly completed by exploration companies, deep crustal seismic, magnetotellurics, gravity and regional airborne geophysics completed by the state and commonwealth governments, and drill hole data completed by exploration companies and the state and commonwealth governments. These coverages are depicted below. Data was extracted from the DNRM website in March 2018.

Geophysical surveys in Queensland (Geophysical Data coverage)

Seismic data coverage (March, 2018)

Seismic data Queensland

The seismic data coverage is mainly concentrated in the southwest corner and the southern central part of the state associated with oil and gas in the Cooper and Surat Basins. Combinations of drilling, geological mapping and seismic data could be integrated to solve local interpretation  anomalies. The 2D and 3D seismic is applicable for the subsurface data and linking to detailed drill hole interpretation of the stratigraphy.

Deep Crustal Seismic and Magnetotelluric surveys (March 2018)

At the margins of mineralised provinces in north Queensland  deep crustal seismic reflection surveys have been completed.  These surveys use the  structural and petrophysical properties of rock bodies to create a depth profile  of the geology. The acquired data (in conjunction with rock properties and geophysical data) enables a much better understanding of the geology and mineral potential of northern Queensland.  It allows the imaging of deep regions of basinal areas and can pick older basin stratigraphy and structural disconformities at a significant depth.

Magnetotellurics (MT) was used along the same lines as the deep crustal seismic surveys. These currents are influenced by rock properties such as type, porosity, permeability and temperature. MT is an electromagnetic technique that measures naturally occurring electric (telluric) currents induced by variations in Earth’s magnetic field.  These techniques were implemented  to image the conductivity of Earth’s crust to similar depths as attained by the deep crustal surveys.

Magentotellurics surveys .

magnetotellurics north Queensland

Airborne Geophysical Data Coverage (March, 2018)

Magnetics radiometrics Queensland

The airborne geophysical data coverage is extensive with only the south-east corner, the northern tropical coast and an area in the central part of the state with no coverage. The south-east has flight restrictions around the major Brisbane and Coolangatta airports and the northern  coast World Heritage tropical rain forest areas are unlikely to be covered by data. Integration of the radiometrics and magnetic data captured by this technique can improve the interpretation of stratigraphic contacts between basin units and show the magnetic (airborne magnetics) and non-magnetic (radiometics) fault features and the features of buried magnetic stratigraphy and igneous rock bodies (magnetics).  This technique is particularly useful to update geological mapping interpretation derived solely from the use of aerial photographic interpretation over sedimentary basins from scales of 1:250 000 to 1:100 000.

Gravity Data over Queensland (March, 2018)

Gravity data detects variation in the density of rock bodies and is appropriate technique to assist in the location of mineral deposits that have a higher density than the surrounding rock bodies.

Gravity Queensland

GSQ has completed  regional gravity surveys with a station spacing that is equal to or less than 4km. The collected data was incorporated into the National Gravity Database.

Drilling Database Queensland  (March 2018)

DNRM and the current Department of Resources, Queensland  has major drilling data over the state derived from departmental and exploration drilling for water, stratigraphic interpretation and energy exploration and this can be downloaded from databases available online.  Departmental custodians of this data that keep the information current in line with legislative controls of data delivery and public availability.  To solve local issue requires access to other and more current company exploratory drilling. The use of drilling data with extensive seismic data can generate a 3D picture of large basin areas and identify the likely presence of fluids in these basins.  This can be accompanied by local knowledge on specific products.

For any additional information on your projects and details of experience contact me.

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