SPENCER GULF: Matthew Flinders & the Coastal Landforms of SE Australia

Sailing and exploring along the southern coast of New Holland, prior to reaching Spencer Gulf, in summer (Feb 1802) had its difficulties ... 'The reflection of the heat from the sand and rock on shore has made it intolerably hot in traveling. Mr. Brown's thermometer stood at 98º [37°C] in the shade, and the island does not in any one part promise to afford a drop of water. On board the ship the heat is much more considerable than we have ever yet felt it to be before.' 'From the great combined heat from of the sun and that reflected from the sand and rocks of the island, and from the bird holes into which we were falling every two or three minutes, I found a walk of about 2 miles to be as much as I could perform.' - Journal of Matthew Flinders [ 3 Feb 1802 ]
By the time the Investigator reached the western mouth of the Gulf water was running low. At the western opening to Spencer Gulf, near present-day Port Lincoln, the ship's boat was sent to land to find fresh water. On its return it ran into trouble; the boat never returned and all eight lives were presumed lost - a catastrophe for the expedition! Wreckage and personal articles, but no human remains, were found during the following days by searching crews, mainly led by Robert Fowler, the ship's first Lieutenant. While Flinders had ordered a thorough search for the missing crew members, the need for water finally forced the expedition to continue. The nearby cape was named Cape Catastrophe and the large island, Thistle Island, in memory of Mr John Thistle, a respected midshipman and close associate of Captain Flinders. Other features were also named after lost crew members. Parts of Flinders' account of the incident and his tribute follow. Ominously, large sharks were sighted in the vicinity.	Flinders' Chart, Cape Catastrophe (extract from Flinders' chart)
The catastrophe and tribute: 'Sent the master in a cutter over to the main to search for fresh water ... At 7, the boat was seen returning but suddenly missed ... Our apprehensions led us to suppose that the boat has been swamped, and that she capsized over them and drifted with the tide to seaward. Only two of the men in the boat were at all expert in swimming.' 'Sent the cutter away in search of the boat and people ... The cutter soon returned, towing the wreck of the other boat, which appeared to have been dashed upon the rocks, nothing remaining except the bottom of the boat which was upwards ... but by nobody was anything of the master or boat's crew seen.' *- Matthew Flinders in Journal, p.349, Feb 1802* ' ... Mr Thistle was truly a valuable man, as a seaman, an officer, and a good member of society ...His loss was severely felt by me; and he was lamented by all on board ... Mr William Taylor ... was a young officer who promised fair to become an ornament to the service ... The six seamen had all volunteered for the voyage. They were active and useful men; and in a small and incomplete ship's company, which had so many duties to perform, this diminution of our force was heavily felt ... ' - Matthew Flinders in Terra Australis
Sortly after the loss of the cutter, the Investigator sailed into a significant water body, named Port Lincoln by Flinders after his home in Lincolnshire, England. Here the sailors reprovisioned the ship with water and any food they could find, the botanists, led by Robert Brown, 'botanised', and Flinders carried out surveys, checked the timekeepers and examined some land features. Memory Cove - Port Lincoln area - Link to SLSA's Flinders Journal - photo version Memory Cove - Port Lincoln area - Link to SLSA's Flinders Journal - text version (Note: text version loads more quickly than photo version)
The crew of the Investigator spent considerable time and effort surveying the mouth, shores and the head ('top') of the Gulf, as well as other major indentations of the coastline. Numerous parties landed, looking for food and water, exploring, and taking records. Flinders' charts finally made clear the true nature of Australia's southern coast, often referred to as the 'Unknown Coast'.	Photo 1: Part of the Spencer Gulf coastline Here in the upper Gulf the water body is moderately wide; it widens further to the left (south) and narrows to the right (North)
Spencer Gulf is a large indentation of Australia's southern coastline. It is part of major north-south geological depression, caused by faulting and subsidence of much of the region millions of years ago. Since then, the region has undergone many geological and geomorphic changes. A major depression, the South Australian shatter zone (including Spencer Gulf), extends south to Kangaroo Island and north to Lake Eyre (which is below sea level). Within sight of the The Gulf are numerous interesting landforms; mud, salt and mangrove flats, weathered surfaces, shoreline beaches and 'cliffs', 'jump up' hills and bluffs, and fault-block uplands.	Photo 2: Flat-topped hill and plateau near the head of the Gulf
Descriptions of entering the gulf ' ... these circumstances, with the trending of the coast to the north, did not fail to excite many conjectures. Large rivers, deep inlets, inland seas, and passages into the Gulf of Carpentaria, were terms frequently used in the conversations of this evening; and the prospect of making an interesting discovery seemed to have infused new life and vigour into every man in the ship.' - *Matthew Flinders in Terra Australis, Feb 1802* 'The coast is of moderate elevation, not sandy, but rather bare of vegetation and of smooth surface: I should judge it to be granite. The mountain ... its top is flat and its N.E. end rather steep ... The land which was unexpectedly seen to the eastward of us ... appears to be part of the main ... at this time we judge ourselves to have entered some large river or gulph.' *- Matthew Flinders in Journal, pps.373, 375, Mar 1802*
The Gulf forms a depositional environment for stream sediments of the area, as it is a low area adjacent to highlands, with lesser water movements than the open ocean. Mangroves grow on tidal portions of the muddy shore. As the ship sailed northward, the gulf became steadily narrower and shallower. Flinders wished to find out exactly what lay at the head of the gulf, and so a group travelled in the small boat as far as possible in the shallow water, landing to take observations. Flinders' description of this exploration is found below. Note: At the same time another group led by Brown, the expedition's botanist, ascended the prominent peak to the south-west (later called Mt Brown) (see Flinders Ranges page).	Photo 3: Gulf waters and portion of S.Flinders Range near head of Gulf (Mt Brown in distance)
At the Head of the Gulf Flinders wrote: ' ... The river being small in this part I did not intend to proceed further until some flights of swans, going downwards induced us to hope for a supply of fresh food. At 10, we had ascended as far a boat could go, the river being scarcely more than a drain from swamps, but was still as salt as below. I observed the longitude here (which see hereafter) and by means of the highest peak on the eastern ridge of mountains I ascertain the head of the river to be in latitude 32º.25'. - So. or 20 miles distant from the ship in a straight line. At noon, we stopped at a red bank on the western shore.' *- Matthew Flinders in Flinders' Journal, 11 Mar 1802* 'Flat topped land ... Bluff ... Middle Mt.' 'Ridge of high, rocky, and barren mountains ... Mt.Brown ... Mt.Arden' 'Low flat land ... Curlew Pt. ... Pt.Lowly ... Low sandy shore, the land rising gradually' 'Mud and sand ... Soft mud ... dry at low wr. ... Great Eastern Shoal' - from Flinders' chart of area near Head of Gulf Head of Gulf - Mt Brown area - SLSA's Flinders Journal - photo version (Note: may take a while to load)
The shoreline of Spencer Gulf ('Gulph' in Flinders' notes) is very indented and complex. To fully explore this, the Investigator had to travel close to the coast, and frequently launch the ship's boat (the cutter). A considerable amount of exploration was carried out on foot, with parties walking along the shore. The numerous shoals of the Gulf made it necessary for the Investigator to sail and navigate carefully. Crew members were posted in key places to look forward at the waters, trying to identify potentially dangerous areas (this took place during all sailing, but especially so in areas of known risk). Soundings were carried out to allow the plotting of a safe course. The presence of shoals meant that a sailing ship had to take an 'erratic' course in such areas, to avoid running aground. Often it could be dangerous to sail close to the shoreline; at such times it was necessary to pass by well out from the shore.	Flinders' chart, Head of Gulf (extract from Flinders' chart)
Flinders' chart makes clear the narrowing of the Gulf to the north. While the botanist Brown and his party climbed a mountain to the east (later called Mt Brown), Flinders left the Investigator, exploring to the very northern limit of the Gulf, a tidal mangrove mud flat, in the cutter. No major river was in sight. For once and for all it was shown that no strait divided Australia nor did any major river reach the sea here. This was a disappointment for most - there was no important positive news to report from the visit to the Head of the Gulf! [ Note: The members of Mr Brown's party, having ascended Mt 'X', were also disappointed with their lack of interesting findings.]
Waves striking the coastline are generally of low energy, especially in the narrow upper Gulf, where winds do not have the reach of the open oceans (where waves may be higher). Gentle waves (and currents) are still able to shift sediments around, forming shoals (shallows) of mud and sand in the Gulf, and shaping the smaller features of the shoreline (such as beaches). The photo (right) shows part of the mainly north-south Flinders Ranges to the east of Spencer Gulf. Much of the rock of the Flinders Ranges is sedimentary. Sandstone and quartzite in particular, form many of the higher ridges due to their resistance to erosion.	Photo 4: Southern Flinders Ranges from near head of Gulf
At the conclusion of the exploration of the great gulf, Flinders wrote: ' ... the investigation of the gulf was terminated, and in honour of the respectable nobleman who presided at the Board of Admiralty when the voyage was planned and ship put into commission, I named it Spencer's Gulf.' - Matthew Flinders in Terra Australis
In summary ... The thought of a major indentation on Australia's south coast exerted particular fascination over early residents of the NSW colony. Matthew Flinders was this gulf's maritime discoverer and first explorer [noting, of course, that indigenous people were aware of this water body well before others]. Because Flinders was primarily interested in gaining maritime knowledge, he and his party took only relatively modest 'excursions' overland to nearby features of interest (most notably Mt Brown). Prior to Flinders' specific investigation of the gulf, some wondered if the Gulf extended so far that it opened on to the northern coast, thereby dividing Australia into eastern and western portions (this, ironically, was in fact so millions of years ago). Flinders was keen to find out the true situation, and although there was disappointment on board the Investigator when it was clear that no great passage to the Gulf of Carpentaria would be found, there was satisfaction knowing that a large blank on the map had been filled in, and that a significant gulf had been charted.	Extract from Flinders' chart - Spencer's Gulf Eyre Peninsula (left), Yorke's Peninsula (right)
Further exploration of the gulf region ... Serious land-based exploration began in the area with Edward John Eyre, an early overlander. He set out in May 1839 to explore the area north of the head of the Gulf and to travel along the western shore to the newly established settlement of Port Lincoln. On the way he traversed the eastern shore, crossing numerous creeks, and reaching the range whose southern end was mapped by Flinders. Eyre named Mt Remarkable and his party was the first to report a species of bettong (a small, kangaroo-like marsupial) - 'they were excellent eating.' The area west of the head of the gulf was shown to be barren and inhospitable. His efforts included numerous probes into areas around the Flinders Ranges, each time seeing the distant, white strips made by Lake Torrens and other dry, salt lakes. His expeditions took him as far north as Lake Eyre South, thinking that it was part of Lake Torrens. He concluded that a gigantic arc of such land surrounded the Flinders, a belief that remained until 1858 when others showed that there were 'land gaps' between a series of vast, but discrete salt lakes.