POST 10 Meandering in the Main Karoo Basin eastern Cape ... 10...Major post-Karoo fault Dykes Growth rings on in situ tree trunks Stop 17: Meandering river channel in the lower Elliot

POST 10

Meandering in the main Karoo

Basin, Eastern Cape, South Africa FIELD TRIP LEADERS:

Emese Bordy & Goonie Marsh

This comprehensive five day trip will take us through, via an unique route in the shortest travel time and

distance, a geo-traverse through 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.

Field Trip Leaders: Emese Bordy and Goonie Marsh

Start: Port Elizabeth

End: Port Elizabeth

Dates: 2-7 September 2016

ITINERARY

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

2 September 2016, Friday Arrival at Port Elizabeth Airport and transfer to Grahamstown

Overnight at the Graham Hotel in Grahamstown BB

Day 2

3 September 2016, Saturday

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

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

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:

Textural features of the tillite (e.g., grain-size range, poor-sorting, roundness, clast types)

Dropstones

Rock colour changes (variable chemical weathering, locally enhanced by fractures)

Massive bedding

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:

Grahamstown Peneplain (silcrete duricrust) around Rhini

Rock colour changes in the tillite (further weathering)

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

Overnight at the Graham Hotel in Grahamstown BB

Day 3

4 September 2016, Sunday

Grahamstown-Aloe Grove.

Stop 4: Glacio-marine tillites, Dwyka Group (Late Carboniferous – Early Permian) Location:

Abandoned quarry, ~15 km NE of Grahamstown

Features to be seen:

Textural features of the tillite (e.g., grain-size range, poor-sorting, roundness, clast types)

Dropstones

Soft-sediment deformation in syn-Dwyka sandstone clasts - Massive bedding

Overnight at the Aloe Guestfarm BB

Day 4

5 September 2016, Monday Queenstown-Tarkastad area.

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:

Architecture of the sandstone units: lateral and vertical accretion

Well-preserved crevasse splays

Floodplain successions with erosional features

Gigantic desiccation cracks

Palaeosol features (pedogenic nodules, root traces)

Trace fossils

Vertebrate fossils

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

Features to be seen at 15:

Medium-grained, tabular, multi-storey sandstones

Erosively based upward-fining cycles

Rip-up mudstone clasts and intraformational conglomerates

Floodplain successions, crevasse-splays, palaeosols, bioturbation and amazing desiccation cracks

In situ fossils from the Earliest Triassic Lystrosaurus Assemblage Zone

In situ vertebrate burrows

Overnight at the Aloe Guestfarm BB

Day 5

6 September 2016, Tuesday

Dordrecht-Jamestown area.

Stop 16: Braided fluvial channel succession and associated organic matter rich floodplain sediments in the

Molteno Formation, Stormberg Group (Late Triassic)

Location: Roadcut along the R56, W of Dordrecht

Features to be seen:

Fluvial architecture: vertical accretion resulting in a multi-storey channel succession

Rip-up mudstone clasts

Trough cross-bedding - roadcut perpendicular to flow direction

Carbonaceous floodplain sediments

Major post-Karoo fault

Dykes

Growth rings on in situ tree trunks

Stop 17: Meandering river channel in the lower Elliot Formation, Stormberg Group (Late Triassic) Location:

Roadcut along the R56, W of the junction of the R56 and N6

Features to be seen:

Fluvial architecture: asymmetrical channel-fill, lateral accretion surfaces and well-preserved steep cut-bank

Rip-up mudstone clasts

Trough cross-bedding - roadcut perpendicular to flow direction

Trace fossils

Potentially dinosaur bone fossils

Small post-Karoo fault

Dykes

Stop 18: Diatremes

Location: near Jamestown, just W of the N6

Features to be seen:

The diatreme & its fascinating story

Near the diatreme, aeolian features in the Clarens Formation (Early Jurassic).

Overnight at the Aloe Guestfarm BB

Day 6

7 September 2016, Wednesday

Departure/travel day

Depart from Aloe Grove Guest Farm via East London to Port Elizabeth. Fly out from East London or in the

evening from Port Elizabeth (some can overnight in Port Elizabeth)

Travel distances on the final day: Aloe Grove Guest Farm – East London = ~200 km; East London - Port

Elizabeth = ~300 km (either via the N2 or the coastal route of R72; weather dependent)

Meal Key

BB Bed and Breakfast

DBB Dinner, Bed and Breakfast

DBB+ Dinner, Bed and Breakfast plus one additional activity

DBB++ Dinner, Bed and Breakfast plus two additional activities

FB Full Board (includes 3 meals per day)

FB+ Full Board (includes 3 meals per day) plus one additional service

FB++ Full Board (includes 3 meals per day) plus two additional services

FI Fully Inclusive (includes all meals and local drinks), plus all activities

MINIMUM NUMBERS 18

MAXIMUM NUMBERS 28

Transfers in 32-seater coach

COST INCLUDES:

• 2 Nights accommodation at Graham Hotel on a BB basis

• 3 Nights accommodation at Aloe Guest Farm on a BB basis

• 5 x lunches

• 4 x dinners

• Handling Fee

• Transport in private touring vehicles

• Local English speaking driver on all transfers

• Local English speaking guide on all sightseeing excursions

• Guide and Driver meals & accommodation where necessary

• Entrance fees to sightseeing venues as stated in the itinerary above

• Porterage at airports on arrival (1 x standard piece of luggage per person)

• 2x 500 ml bottled water a day

COST EXCLUDES

• All airfares, air reservations and airport taxes

• All other accommodation

• All other meals

• All other transport

• All other sightseeing

• Personal expenses such as tips for meals, gratuities for guides & drivers, all alcoholic and other beverages,

telephone calls and laundry

• Any other services not mentioned above