This comprehensive five day trip will take us through, via an unique route in the shortest travel time and distance, a geo-traverse trough over 400 million years of South African geological history. The main focus of the field trip is the sedimentary fill of the southern main Karoo Basin, including the nature of some of the major Karoo intrusive and volcanic complexes of the Eastern Cape. Simplified geological map of the main Karoo Basin (left) and the overview map (right) of the 18 stops of the 5 day field trip in the Eastern Cape, South Africa. Day Date Area Themes Main Stops 0 05/09, Port Elizabeth to African Safari after meeting at the Port Addo Elephant Park Mon. Grahamstown; overnight in Elizabeth airport Grahamstown 1 06/09, Grahamstown; overnight in Introduction to the Phanerozoic history on Vicinity of Grahamstown Tues. Grahamstown South Africa – an Eastern Cape perspective 2 07/09, Grahamstown to Aloe Sed.: Dwyka, Ecca and Beaufort Groups Ecca Pass; Elandsberg; Wed. Grove; overnight at Aloe (tillites, turbidites, Permian, P-Tr boundary, Waterdown Dam; Cathcart Grove Early Triassic fluvial) Ign.: Deep sills 3 08/09, Queenstown-Cradock- Sed.: Katberg & Burgersdorp Fms. (fluvial, Queenstown; Thurs. Queenstown; overnight at Early Triassic) Tarkastad/Golden Valley; Aloe Grove Ign.: Saucer-shaped intrusions Cradock 4 09/09, Queenstown- Jamestown- Sed.: Molteno, Elliot and Clarens Fms. Dordrecht, Jamestown Fri. Queenstown; overnight at (fluvial, aeolian, lacustrine, Late Triassic – Aloe Grove Early Jurassic) Ign.: Hydrothermal vent complexes 5 10/09, Aloe Grove to Port Travel to major domestic airports East London; Grahamstown; Sat. Elizabeth via East London* Port Elizabeth Contact of the field trip leaders: Emese M. Bordy, University of Cape Town; Ph. +27-8471-345-81; email: [email protected] Goonie Marsh, Rhodes University, Grahamstown; Ph. +27-46-603-8309; email: [email protected] Dates: 5-10 August 2016 (post-congress trip) Start – End: Port Elizabeth - Port Elizabeth/East London Number of participants: max. 26 (excluding guides & drivers) Transport: 2 x 22 seater buses, one single cab bakkie for the luggage Brochure: Comprehensive field guide will be issued to every participant Detailed itinerary Day 0 Arrival/travel day; Overnight in Grahamstown. Welcoming the field trip participants at the Port Elizabeth Airport (preferably in the morning*). Drive to Grahamstown via Addo Elephant Park. We would collect the participants two or three times during the day to cater for the different arrival times at the Port Elizabeth Airport. If the last group will arrive after 2 pm, there would be no time to visit the Addo Elephant Park, and this group will have to be taken straight to Grahamstown. Day 1 Stop 1: Overview of 400 million years of South African geological history though the rocks and landscape of Grahamstown, Eastern Cape. Topics covered: Cape and Karoo systems, formation of the main Karoo Basin and Cape Fold Belt, Gondwana breakup, Cenozoic sea level changes. Location: 1820 Settlers' Monument Features to be seen: Relationship of the geology and geomorphology a) Cape Fold Belt - large-scale geological and geomorphological features: • Witteberg quartzite ridges with some mudstone lenses to the south (cut by the N2 national road) & to the north (called Botha’s Ridge) running across the horizon. • City bowl overlying the E-W running contact between soft Witteberg mudstones to the south and Dwyka tillites to the north b) Flat peneplain underlain by hard silcretes (with Joza/ King’s Flat township on it), visible along the northeastern horizon. Stop 2: Tillites of the Dwyka Group (Late Carboniferous – Early Permian) in various wreathing stages Location: Roadcut along the N2, SE of Grahamstown Features to be seen: 1. Textural features of the tillite (e.g., grain-size range, poor-sorting, roundness, clast types) 2. Dropstones 3. Rock colour changes (variable chemical weathering, locally enhanced by fractures) 4. Massive bedding 5. Quartzite-mudstone contact in the Witteberg Group - marked by vegetation change. Stop 3: Tertiary peneplain and associated chemical sediments (weathering profiles with silcrete, kaolinite, etc.) of the Grahamstown Formation Location: Roadcuts along the N2, SE of Grahamstown and Makana’s Kop Features to be seen: 1. Grahamstown Peneplain (silcrete duricrust) around Rhini 2. Rock colour changes in the tillite (further weathering) 3. Weathering profiles in the highly bleached Dwyka tillites with silcrete, kaolinite, Liesegang bands and ghost-dropstones Social/cultural: Visit of the Albany Museum (Karoo display) and dinner in town DAY 2 Grahamstown-Aloe Grove. Overnight at Aloe Grove Guest Farm. Stop 4: Glacio-marine tillites, Dwyka Group (Late Carboniferous – Early Permian) Location: Abandoned quarry, ~15 km NE of Grahamstown Features to be seen: 1. Textural features of the tillite (e.g., grain-size range, poor-sorting, roundness, clast types) 2. Dropstones 3. Soft-sediment deformation in syn-Dwyka sandstone clasts 4. Massive bedding 5. Fresh and weathered rock colour - bluish-black matrix 6. Compacted nature of the tillites – the “claystone porphyry” of AG Bains (1856) Stop 5: Hemipelagic sediments, Whitehill and Collingham Formations, Ecca Group (Early Permian) Location: Roadcut along the R67, Ecca Pass Features to be seen: 1. Thinly bedded, organic matter rich hemipelagics 2. Lateral continuity of beds 3. Interbedded, weathered yellow-cream tuffs 4. Deep water trace fossils 5. Plant fragments Stop 6: Distal and proximal turbidites, Ripon Formation, Ecca Group (Early Permian) Location: Roadcut along the R67, Ecca Pass Features to be seen: 1. Sharp, but non-erosional contact (downlap) between turbidites and hemipelagics (submarine fan and basin floor contact) 2. Incomplete Bouma-sequences: erosional bases, sole marks (gutter casts, flute marks, etc.), rip-up mudstone clasts, massive beds, convolute bedding, rare ripple cross-lamination, low- angle cross-bedding 3. Interbedded, organic matter rich hemipelagics (background sediments) 4. Deep water trace fossils 5. Increase in sandstone thickness and grain size towards n (younging direction – upward shallowing) Stop 7: Elusive Permo-Triassic Boundary, Palingskloof Member, Balfour Formation, Adelaide Subgroup, Beaufort Group (Permo-Triassic) Location: Roadcut along the R67, Nico Malan Pass Features to be seen: 1. The Permo-Triassic Boundary – supposedly just a few 10s of m below the contact of the Balfour and Katberg Formations 2. Contact metamorphic features in red and grey mudstones intruded by dolerites Stop 8: Dolerite sills and aureoles [stratigraphically in the lowermost Katberg Formation, Tarkastad Subgroup, Beaufort Group (Early Triassic)] Location: Roadcut along the R67, Elandsberg, Nico Malan Pass Stop 9: Sedimentary dykes in dolerites [stratigraphically in the Katberg Formation, Tarkastad Subgroup, Beaufort Group (Early Triassic)] Location: Roadcut along the R67, E of the Waterdown Dam Stop 10: Braided fluvial deposits in the Katberg Formation, Tarkastad Subgroup, Beaufort Group (Early Triassic) Location: Roadcut along the R351, SE of the Waterdown Dam Features to be seen: 1. Medium-grained, tabular, multi-storey sandstones 2. Erosively based upward-fining cycles 3. Rip-up mudstone clasts and intraformational breccias/conglomerates 4. Planar and trough cross-bedding 5. Ripple cross-lamination 6. Fossil dune covered in ripple marks and muddrapes 7. Sand filled desiccation cracks in interchannel mudstones Stop 11: Braided fluvial deposits in the Katberg Formation, Tarkastad Subgroup, Beaufort Group (Early Triassic) Location: Roadcut along the old N6, north of the junction between R351 and N6 Features to be seen: 1. Medium-grained, tabular, multi-storey sandstones 2. Lateral accretion surfaces 3. Erosively based upward-fining cycles 4. Rip-up mudstone clasts and intraformational breccias/conglomerates 5. Floodplain successions with crevasse-splays, bioturbation and paleosols 6. In situ fossils from the Early Triassic Lystrosaurus Assemblage Zone 7. In situ vertebrate burrows DAY 3 Queenstown-Tarkastad area. Overnight at Aloe Grove Guest Farm. Stops 12 & 13: Meandering river deposits in the Burgersdorp Formation, Tarkastad Subgroup, Beaufort Group (Early to Mid-Triassic) intersected by dolerite dykes Location: Roadcuts along R394 (to Lady Frere -12) and R392 (to Dordrecht -13) – NB Stop 12 (Nonesis Neck Pass) is part of the global biostratigraphic standard for the non-marine Triassic; it displays the world famous late Early to early Mid-Triassic Cynognathus Assemblage Zone. Features to be seen: 1. Architecture of the sandstone units: lateral and vertical accretion 2. Well-preserved crevasse splays 3. Floodplain successions with erosional features 4. Gigantic desiccation cracks 5. Palaeosol features (pedogenic nodules, root traces) 6. Trace fossils 7. Vertebrate fossils 8. Karoo dolerite intrusions and their relationship to the jacked up sedimentary successions Stop 14: Golden Valley sill complex [stratigraphically in the Burgersdorp Formation, Tarkastad Subgroup, Beaufort Group (Early to Mid-Triassic)] Location: Roadcut along the R344, N of Tarkastad Stop 15: Vertebrate burrows in the lower Katberg Formation, Tarkastad Subgroup, Beaufort Group (Early Triassic) Location: Roadcut along the R61, ENE of Cradock PT boundary - just to the south, near Kommandodrif Dam at 32°10'10.38"S 26° 3'11.94"E (for more on these vertebrate burrows, see Bordy et al. 2011 and for more on this PTB section, see De Kock & Kirschvink 2004 Features to be seen at